A pod of killer whales has sunk another yacht off northwestern Spain, reinforcing a bizarre pattern of vessel encounters that has stretched on for more than six years along the Iberian coast.

In the incident, reported Friday (July 24), the whales destroyed the rudder of a 46-foot-long (14 meters) Swedish-flagged yacht off Galicia in northwestern Spain, forcing the two people aboard to send a mayday call. A Spanish coastguard vessel towed them to safety, Spain-based news outlet Sur in English reported.

The incident came after several other encounters in the same waters earlier that week, including one in which a pleasure craft called the Idem sank near Estaca de Bares, the northernmost point of the Iberian Peninsula. The ship sank after the killer whales, also known as orcas (Orcinus orca), destroyed its rudder. Both occupants were rescued.

That makes the Idem at least the eighth boat lost to these encounters since they began, according to groups that track the incidents. More than 700 interactions between orcas and vessels have been logged since 2020, ranging from a brief nudge to a multihour rudder-ramming session, according to the Atlantic Orca Working Group, the Spanish-Portuguese research collective that has coordinated data collection on the phenomenon from the start.

Researchers have identified roughly 15 individual killer whales involved in these incidents, out of an Iberian subpopulation of fewer than 50. The group is so small that the International Union for Conservation of Nature lists it as critically endangered, as it is dependent mainly on Atlantic bluefin tuna for its food.

The family-like cluster is thought to be led by a female known as White Gladis. That name comes from an early theory researchers themselves once floated: that White Gladis suffered some kind of traumatic run-in with a boat and that the encounter flipped a behavioral switch, with her being the first in the group to start ramming rudders.

Alfredo López Fernandez, a biologist with the Atlantic Orca Working Group, told Live Science in 2023 that this kind of defensive, trauma-driven origin was gaining traction among researchers at the time. But "defensive" isn't "vengeful" — and the idea has since curdled online into a punchier revenge story most scientists studying the population don't endorse.

So why do orcas go after the boats? Nobody knows for certain, but the leading explanation is simple: Orcas are some of the most social animals on the planet, and social animals pick up habits from one another the way trends spread through a friend group. Researchers describe the behavior as socially learned — young orcas appear to watch adults ram a rudder and then try it themselves, and the habit has spread through the group over time.

A 2022 study in the journal Marine Mammal Science found that the killer whales usually targeted sailing boats and often lost interest after striking the rudder and causing the boat to stop.

None of that makes the encounters any less disruptive for the people living through them. The standard guidance from authorities like the Maritime Safety and Rescue Society and the Atlantic Orca Working Group, refined over repeated encounters, is to cut the engine, drop the sails if possible, disengage the autopilot, and let go of the wheel entirely, giving the orcas nothing to push against. Boats that follow this protocol tend to sustain less damage than those that don’t.

Sailors are asked to report every encounter. Each one adds to the data scientists are using to try to solve a years-long mystery.

One of the ocean's most intelligent and aggressive predators has once again surprised scientists with a curious new behavior. In the Gulf of California, researchers witnessed orcas working together to smash dead sunfish into bits — a suspected food processing technique that makes it easier for younger whales to feed on the enormous bony fish that weigh up to 4,400 pounds (2,000 kilograms).

In two separate encounters, one orca gripped a sharp-tail sunfish (Masturus lanceolatus) while another orca charged toward the fish. The first whale released the carcass just before impact, allowing its companion to slam into the fish at high speed and scatter fragments of fish flesh throughout the water.

"It was unlike anything I'd witnessed before," Kathryn Ayres, a scientist at the conservation nonprofit Beneath the Waves told Live Science in an email. "As a scientist, moments like this are incredibly exciting because you realize you're observing something that may never have been documented in detail before — as you can tell in the video!"

Ayres and her colleagues dubbed the behavior "ram-to-fragment." Their observations, published July 23 in the journal Frontiers in Ethology, suggest the killer whales were not trying to kill the sunfish, which were already dead and appeared to have been disembowelled. Instead, the orcas may have been breaking down the bulky carcasses so members of the group, particularly younger animals, could feed more easily.

Hunting in action

The first encounter Ayres observed took place in July 2024 near an offshore seamount off Baja California Sur, Mexico. An adult female orca held a sharp-tail sunfish by its tail-like clavus, or rudder, while an adult male orca accelerated toward it, belly-up. The female released the fish an instant before the male struck.

The collision produced a loud noise and caused the sunfish's tissue to disintegrate. In the video, Ayres' shock is evident as she can be heard exclaiming, "Oh my god!"

A juvenile orca then swam into the cloud of suspended flesh and ate the smaller pieces, while the adults fed on what remained of the main carcass.

A second encounter, which the researchers credited diver Héctor Franz for filming in September 2025, followed much of the same sequence. One adult orca stabilized the sunfish, another rammed it and a calf later pulled tissue from the broken carcass.

Ayres had previously watched orcas hunt ocean sunfish (Mola mola), but this was different.

"I had also seen orcas ram their prey previously, but I had never witnessed an impact powerful enough to completely fragment the tissue like this," Ayres said. "That was what made this observation so remarkable."

The maneuver resembled coordinated attacks Ayres and her team had previously documented, in which orcas confronted whale sharks (Rhincodon typus) — the largest living fish — in the Gulf of California. In those hunts, some orcas took turns ramming it.

Why make fish confetti?

Ramming is not a new killer whale hunting technique, said Matt Hansen, a postdoctoral researcher at the Leibniz Institute of Freshwater Ecology and Inland Fisheries who was not involved in the study. However, the hold-and-release sequences and shattering of carcasses may be new, Hansen told Live Science in an email.

The researchers proposed several possible explanations for the behavior. The predominant assumption is that the adults were processing food for younger whales. Orcas frequently tear apart prey and share portions with calves and juveniles, and in both newly described encounters, young killer whales were present.

But two observations are not enough to show that the adults were deliberately feeding or teaching the youngsters, Heather Hill, a professor and chair of psychology at St. Mary's University in Texas who was not involved in the research, told Live Science in an email.

"Whether or not it represents parental investment, observational learning, or distribution of resources remains circumstantial in my opinion," she said.

The researchers also suggested that the behavior could have been playful. Orcas are highly intelligent and social, and they sometimes manipulate, toss or strike prey without immediately eating it. However, Hill said that the two encounters appeared more practical than playful.

"If it was for fun, I would have expected multiple attempts made with variations in speed, point of contact, force of impact, and initiators because the point of playing is to try different things and not destroy the toy too soon," she said. "Since it appears that these events were 'one and done' so to speak, probably less playful and more functional — to eat the fish and maybe to model a foraging technique and possibly to share resources with the younger animal."

The study authors also raise a more speculative possibility that dispersing the sunfish's microbe-rich skin and gelatinous tissue could somehow affect the surrounding water or expose the orcas to potentially beneficial microbes. But what that benefit might be is unclear.

"I don't see how dispersing the skin into the water column would have a different effect from eating it," Hansen said. "Unless the authors are suggesting [the orcas] are using it like a lotion on their own skin? Who knows, the world is weird and wonderful."

Orca quiz: Will you sink or swim?

An isolated population of sperm whales in the Mediterranean Sea are splitting into two distinct groups with different dialects, a new study reveals. This shift has likely been happening for thousands of years, as two groups split from an initial single population.

The findings, published Tuesday (June 23) in the journal Proceedings of the Royal Society B: Biological Sciences, are providing a rare insight into the process of different dialects emerging among non-human species.

The sperm whales (Physeter macrocephalus) live in small social units of females and young, and they associate with other groups in the same area. They use social vocalizations called codas ‪—‬ shortpatterns of clicks ‪—‬ to communicate. The particular codas they use identify them as being part of the same cultural group.

Taylor Hersh, a researcher in the School of Biological Sciences at the University of Bristol in the U.K. and first author of the research, and her colleagues have analyzed codas recorded over almost 20 years in the Mediterranean, where there is a unique population of a few thousand sperm whales, to see if they all use the same dialect.

Sperm whales entered the Mediterranean via the Strait of Gibraltar about 20,000 years ago, and they have spread throughout the area. The whales rarely leave the sea ‪—‬ even males, which normally migrate. Other sperm whales don't seem to enter often, either, so the Mediterranean ones are effectively isolated from other populations and are considered an endangered subpopulation.

"The sperm whales in the Mediterranean are really cool," Hersh told Live Science. "I've always thought of them as the weirdos of the sperm whale world in that they don't leave through the Strait of Gibraltar even though they could. They are unique, and for a long time, they were also thought to be acoustically unique."

The thinking was that all the sperm whales in the Mediterranean belonged to the same clan, identified by their use of a single coda 90% of the time. This coda consists of three clicks and then a pause before the fourth and final click ‪—‬ a pattern called the three-plus-one type.

But the analysis by Hersh's team of 5,291 codas recorded between 2003 and 2021 revealed that sperm whales living in the eastern Mediterranean around the Hellenic Trench, off Greece, have a slightly different dialect from that used by animals in the western basin around Spain's Balearic Islands.

The eastern whales produce a distinct form of the three-plus-one coda. "It's a very similar pattern of clicks, but it's much, much faster," Hersh said.

In some recordings, whales in the eastern Mediterranean produced the slower coda, showing they were familiar with both dialects.

"The western sperm whales religiously stick to their dialect, but there were four instances of eastern whales using the western dialect," Hersh said. "The question of why is still an open one. Their dialect seems to be a lot more diverse than we expected. They do occasionally make those slow three-plus-one codas, but they make a lot of other coda types, too."

Hersh hopes further recordings alongside records that tie individual whales to sounds and events might help elucidate why the whales switch between dialects.

"It's exciting to see this study showing different populations behaving closely, but also differently," said Gašper Beguš, linguistics lead at Project CETI, a nonprofit organization that aims to translate the communication of sperm whales.

The study paints a picture of sperm whales progressively occupying the Mediterranean from west to east, with the dialect of one group gradually changing. "The groups in the east clearly remember the western dialect because they have these 'throwback' days," Hersh said.

It's still a mystery how and why these dialects evolved.

"Every speech is a dialect; the question is how did they arise and why?" said Beguš, who wasn't involved in the new study. He said the historical change in habitat does help to show which dialect came first. "In the Mediterranean, maybe they're forming different groups, so that's why they're trying to distinguish themselves," he told Live Science, giving the parallel of young people who distinguish themselves from previous generations by coming up with new slang.

"It's possible that these two groups with repertoires that are very similar but still distinctive could represent a sort of midway phase,” Ellen Jacobs, a marine biologist at Aarhus University in Denmark who wasn't involved in the research, told Live Science via email.

"Changes in the rhythm might be a very feasible and meaningful way for coda signals to start to diverge," she said, like the way the English words "How do you do?" got mashed together until they morphed into "howdy."

The timescale on which a sperm whale dialect develops is uncertain, but it's likely a slow process, according to Hersh. "It's probably happening on the scale of hundreds and thousands of years, because sperm whales can live into their 60s and 70s. And this study is looking over 19 years of data, and that's just a snapshot of one animal's life," Hersh said.

This means the eastern whale dialect was conceivably emerging in the Mediterranean Sea as famous human civilizations were speaking different languages on the surrounding lands, including when the ancient Greeks and Romans were rising and then falling.

"Maybe if we could leave them for another 10,000 years, we would come back to find the completely separated dialects of clans," Jacobs said.

Scientists have discovered a vast whale graveyard stretching for hundreds of miles in the Indian Ocean, with some fossil bones dating back over 5 million years.

The deep-sea "megasite," which the researchers have named the Diamantina Zone necropolis, is the most extensive accumulation of whale carcasses and fossils ever found, the researchers reported in a new study published Wednesday (June 10) in the journal Nature.

"It covers over 1,200 kilometers [750 miles], which just defies belief," Nick Pyenson, a curator of fossil marine mammals at the Smithsonian National Museum of Natural History in Washington, D.C., who wasn't involved in the study, told Live Science. "'Megasite' is a totally appropriate term. I think they've uncovered something really special."

"The density is crazy"

Xiaotong Peng, a deep-sea researcher at the Chinese Academy of Sciences' Institute of Deep-sea Science and Engineering, and his colleagues used an underwater vehicle called the Fendouzhe submersible to survey the seafloor in the Diamantina Zone, an area of ridges and fractures in the southeastern Indian Ocean.

After initially spotting one fossil, the team conducted 32 dives covering a survey area of about 0.25 square miles (0.64 square kilometers). In total, they identified 476 whale fossils and five carcasses of whales that had died more recently, known as whale falls, at depths of between 13,800 and 23,000 feet (4,200 to 7,000 meters).

Extrapolating from these figures, the authors said there could be seven to eight whale carcasses and about 750 fossils per square kilometer in the area.

The largest carcass is a 16.4-foot-long (5 m) skeleton from an Antarctic minke whale (Balaenoptera bonaerensis), the researchers said, but most of the remains are from beaked whales ‪—‬ marine mammals we know little about because they live in the open ocean and spend a lot of time diving.

The five active whale falls are covered in bacteria that live without light or oxygen and break down the oils in the whales' bones, producing hydrogen sulfide. This source of chemical energy enables the carcasses to host diverse communities of jellyfish, brittle stars, bone-eating Osedax worms and bivalve mollusks, which together reach densities of up to 2,840 individuals per square meter, the authors discovered.

Many of the members of the whale-fall communities may also be newly discovered species, the authors wrote, because although most could be matched to the genus or family level using DNA data from samples, only one could be confidently assigned to a species: a clam known as Abyssogena southwardae.

"The density is crazy, as is the fact that they're probably all new to science," said Stephen Godfrey, curator of paleontology at the Calvert Marine Museum in Maryland who wasn't involved in the study. "It's like each one of these whale falls is a new little restaurant that opens up in a 1,200-kilometer-long [745 miles] strip mall," he told Live Science.

These are the deepest whale-fall communities ever found, with the one at about 22,000 feet (6,700 m) being about 8,200 feet (2,500 m) deeper than any other known one, according to the study authors.

A fossil deposit being formed

Peng and his colleagues recovered 43 fossils and dated 33 of them based on the ratios of strontium isotopes present. The fossils belonged to five beaked whale species and one species of baleen whale, a group that includes bowhead and humpback whales.

The oldest fossil found in the area belonged to an extinct beaked whale in the Pterocetus genus that dates back about 5.3 million years, to the Early Pliocene. Another fossil find represented a new species, which the authors have named Pterocetus diamantina.

All that remains of most of the specimens is the bony upper jaw, or rostrum. These fossils came mainly from two species: the Andrews' beaked whale (Mesoplodon bowdoini) and the strap-toothed whale (Mesoplodon layardii). Both of these species still inhabit the Indian Ocean, but the fossils the team discovered could be up to 1 million years old.

"The really awesome thing is that this megasite is showing beaked whale ecology over geologic time scales, so you are getting extinct species overlapping the fossil remains of extant species," Pyenson said.

The megasite is analogous to either the famous Lagerstätte fossil deposits, where there is high-quality preservation, including of soft tissue, or to the Burgess Shale in Canada, which has a huge abundance of animals, Godfrey said, "only here, you have one that's still forming."

Beaked whales are rarely seen, so it might seem strange to find the remains of so many individuals in one place. But Godfrey said these animals might preserve better because of the staying power of their rostra, which have one of the highest known bone densities and mineral contents among living vertebrates.

This means they can persist long enough at great depths without being dissolved or consumed by bone-eating worms that they then become encrusted with ferromanganese oxides, solidifying and encasing the bone in a kind of natural sarcophagus.

"This seals the specimen in, so it will last in perpetuity, or at least over 5 million years, and who knows how much longer," Godfrey said.

Why so many dead whales?

The authors saw many squid and fish in the dives in the Diamantina Zone, which suggests the area provides an ideal deep-water foraging ground for beaked whales. This might mean more whales live and die in the area, even though when a whale dies, its decomposition can make it expand with gas and float on the surface for great distances before eventually falling to the seabed.

Peng and his colleagues also suggested that there might be an increased risk of death by beaked whales being tempted to chase prey below their maximum observed diving depth of about 10,000 feet (3,000 m), which puts them at risk of lung collapse or decompression sickness.

Another possibility is that the V-shaped topography of the Diamantina Zone may funnel sinking carcasses into a smaller area, the authors suggested.

"I think what they're dealing with is an analogue to the terrestrial tar pits or caves that are natural traps where biological remains accumulate over time," Pyenson said.

That's only part of the story, though. Normally, ancient remains on the seabed would get covered by sediment from eroded rocks, so we'd never see the fossils. But the sedimentation rate close to the Diamantina Zone is incredibly low ‪—‬ just 0.02 to 0.22 inches (0.05 to 0.55 centimeters) per 1,000 years, the study authors noted. This means skeletal remains could be exposed for hundreds of thousands of years at the flat bottom parts of the zone and for millions of years on slopes or uplifted sections, the team said.

They think there might be other similar "necropolises" off South Africa, the Iberian Peninsula, and the remote Crozet and Kerguelen islands near Antarctica, where some fossils have already been discovered by trawling.

How much do you know about killer whales? Find out with our orca quiz!

Sable Island, off the coast of Nova Scotia, is home to the world's largest gray seal breeding colony — and the site of a gruesome, decades-old mystery that's finally been solved.

Reports of traumatically injured seals have plagued Sable Island since at least 1980. Gray seal (Halichoerus grypus) pups were found with strange spiral-shaped lacerations that tore to the bone, starting at the seals' mouths and winding down to their chests. The oddly shaped injuries led scientists to guess the culprit might be sharks or ship propellers. However, there was no direct evidence to confirm either of those theories.

Now, new research reveals the real corkscrew killers: cannibalistic male gray seals.

Species across the animal kingdom engage in cannibalistic behavior. Cannibalism was first documented in gray seals in Nova Scotia in 1992, and since then, there have been other cases of gray seals preying on pups of their own species.

In 2016, gray seal cannibalism was recorded in Scotland, with direct observations confirming this was the cause of corkscrew-shaped lacerations. Yet gray seal cannibalism still hadn't been observed directly on Sable Island.

"Cannibalism so far has been frequently observed in grey seals," Ursula Siebert, a wildlife researcher at the University of Veterinary Medicine Hannover in Germany who was not involved with the new research, told Live Science in an email. "There was a high potential that this behavior would also be detected [on Sable Island] after we understood the phenomenon."

In 2024, the authors of the new study finally witnessed an adult male gray seal attacking a pup on Sable Island. They began to closely examine seal pups with the spiral-shaped injuries throughout the island, and found bite and claw marks on the animals' skin and blubber that looked like the work of gray seals.

The new paper, published Feb. 4 in the journal Marine Mammal Science, reports these firsthand accounts of gray seal cannibalism on Sable Island. Reanalyzing drone footage from 2023 as well, the research team recorded instances of adult male gray seals feeding on gray seal pups from 2023 through 2025.

Overall, the researchers found 765 seal pups with corkscrew markings during the 2024 breeding season. On a single day in 2025, they found 359 pups that had died from these injuries. However, this may not necessarily indicate that there was a spike in attacks but rather that scientists improved their searches for these pups.

"We were certainly relieved to have an answer to the cause of these deaths," Damian Lidgard, a biologist at Fisheries and Oceans Canada and co-author of the new study, told Live Science in an email. For years, the cause was assumed to be shark predation, Lidgard added, but without any observations of sharks causing these deaths at Sable Island. With instances of male gray seal cannibalism elsewhere, the researchers were not surprised to discover the cause, he said.

The researchers don't necessarily think the behavior is a cause for alarm. "The most recent estimate of grey seal pup production on Sable Island is about 75,000," Lidgard said. "Given that the number of pup deaths from male grey seals is estimated at under 1,000, there is no significant impact of cannibalism on the seal population on Sable Island."

However, understanding the cause of seal pup deaths is important for the management and conservation of the island.

Although cannibalistic behavior has only been recorded in male gray seals on Sable Island, Lidgard said, it is possible that male gray seals are also targeting harbor seal (Phoca vitulina) pups that live on Sable Island, since this has been observed in Europe.

"Grey seals not only practice cannibalism, but also kill other marine mammals such as harbour seals," Siebert said, "[so] it can become a threat to those populations."

"Harbour seal pup production on Sable Island is very small," with populations in decline in recent decades, Lidgard noted, so this is potentially concerning.

The researchers added that the cause behind the cannibalism remains unknown.

"We are not sure why this is occurring on Sable or in other locations," Lidgard said. "This may be a natural behaviour of grey seal males (as observed in other species) that has only recently been observed and documented. It might be a learned behaviour from an individual but that is unlikely given that it occurs on Sable and in the UK which are genetically/behaviourally isolated. I could keep providing hypotheses but really we don't understand the cause."

Scientists are scratching their heads over why three mammal-eating orcas turned up in Seattle waters in March, having apparently traveled 1,500 to 2,000 miles (2,400 to 3,200 kilometers) south from Alaska.

"It's extremely rare to have previously undocumented killer whales show up in local waters, so it's been very exciting to see them, and right now we have more questions than answers," Monika Wieland Shields, the director of the Orca Behavioral Institute, a Seattle-based non-profit research organization, told Live Science in an email.

The pod is composed of three killer whales, likely a mother and her two offspring, one of which is a full-grown male, the Associated Press reported. By identifying individual markings on the whales' fins and side colorations, researchers can track the movements of these animals across the Pacific Northwest. That's how they discovered that the pod had traveled from Alaska, after finding photos of the group from last year, according to the AP.

Killer whales (Orcinus orca) tend to travel within established ranges and return to the same areas and hunting grounds over years and even generations. If these orcas are in fact well outside their usual range, their presence could signal that something has shifted in prey availability, ocean conditions or the whales' own behavior.

"We really have no idea what compels an individual whale to travel outside of their regular territory!" Wieland Shields said. "Thanks to decades of research and the ability to identify individual whales through photo ID, we know all of the individuals and families that regularly visit this region, including their approximate ages and family relationships. … Without this work, we wouldn't even know that these new visitors are unusual!"

A shift in whale populations

Two types of orca subspecies live in the Salish Sea between Washington and Canada: endangered fish-eating Southern resident killer whales and mammal-eating Bigg's killer whales.

These groups' range have changed dramatically over the past few years as a result of shifts in food availability, Wieland Shields said.

"The Southern Residents no longer have abundant, reliable wild salmon to feed on here, so they've shifted their travel patterns elsewhere," Wieland Shields said. "Bigg's killer whales are here in ever-increasing numbers because the populations of their primary prey in the region — harbor seals, harbor porpoise[s] and Steller sea lions — are all booming."

Experts think this could be why the new pod, identified as Bigg's killer whales, is so far south.

"I am inclined to agree with a report that they may be following some food options," Heather Hill, a psychologist focusing on marine mammal behavior at St. Mary's University in San Antonio, told Live Science in an email. "They can be indicators of [the] health of an area — the whole food chain idea. Studying the different pods also helps us understand their social dynamics, such as how they share the same space with other transients or residents."

For Seattle-based Wieland Shields, the pod's arrival raises many more questions. "Until we have further acoustic and/or genetic evidence, we don't know exactly which population they are from, and we have no idea how long they will stay."

Think you know your orcas? Test your knowledge with our orca quiz!

Scientists have captured first-of-its-kind footage of a sperm whale violently headbutting another sperm whale out of the blue.

Researchers filmed the clip with a drone during fieldwork off the Azores and Balearic Islands. It is one of three cases of headbutting between 2020 and 2022 that the scientists reported in a new study published Monday (March 23) in the journal Marine Mammal Science.

"It was really exciting to observe this behaviour, which we knew had been hypothesised for such a long time, but not yet documented and described systematically," study lead author Alec Burslem, a quantitative physiological ecologist at the University of Hawaii, said in a statement.

Mariners and whalers in the 18th and 19th centuries told stories of sperm whales (Physeter macrocephalus) using their heads to push each other and strike boats. The most famous anecdote dates to 1820, when an 89-foot-long (27 meters) whaleship called the Essex reportedly sank after a large male sperm whale headbutted it twice off the Galapagos Islands, according to the statement.

Reports of the Essex's sinking inspired Herman Melville's 1851 novel "Moby Dick," which tells the fictional story of a whaleship captain's obsessive and vengeful quest to find a giant white sperm whale that bit off his leg.

However, until now, scientists had never documented sperm whales' headbutting behavior.

It's still unclear exactly why sperm whales headbutt each other, but some researchers think the behavior originated from competition and physical contests between males, according to the statement. Other experts argue that headbutting is unlikely to have evolved as a widespread behavior in sperm whales, however, because using the head as a weapon can damage brain structures in these whales that are vital for echolocation and social communication.

The footage showed young males participating in headbutting, rather than mature males as was previously hypothesized, raising questions about the role of the behavior in whale groups.

It's possible that headbutting is common in sperm whales, and that researchers are only seeing it now thanks to better and more accessible technology.

"This unique overhead perspective for observing and documenting near-surface behaviour is just one of the ways drone technology is transforming the study of wildlife biology," said Burslem, who was at the University of St Andrews in Scotland when he did this research.

"It's exciting to think about what as-yet unseen behaviours we may soon uncover, as well [as] how more headbutting observations may help us to shed light on the functions the behaviour may serve," he said. "If there are people out there with similar footage, we would be very keen to hear from them."

Animal quiz: Test yourself on these fun animal trivia questions

Orca fins washing up in the North Pacific are scratched with characteristic tooth marks that suggest killer whales are occasionally cannibals. Scientists say this may explain why some orcas live in large family groups.

Orcas (Orcinus orca) come in several distinct types, sometimes considered different subspecies. In the North Pacific Ocean, two of these types inhabit roughly the same areas: Resident orcas (Orcinus orca ater) live in large family groups and eat fish, and Bigg's orcas (Orcinus orca rectipinnus), which are more common and transient, live in smaller groups and hunt other mammals, such as whales, dolphins and seals.

Generally, it was thought the two types avoided each other. But Olga Filatova, a whale researcher at the University of Southern Denmark, and her colleagues have uncovered evidence showing that's not always the case. They published their findings Feb. 24 in the journal Marine Mammal Science.

In August 2022, study co-author Sergey Fomin, a researcher at the Pacific Institute of Geography in Russia, found an orca fin on a beach on Bering Island in eastern Russia. The fin was bloodied and covered with tooth marks.

It isn't that unusual to find fins with such tooth marks. But previous such fins had belonged to Baird's beaked whales (Berardius bairdii) and minke whales (Balaenoptera acutorostrata) that had been attacked and eaten by Bigg's orcas.

"He immediately thought, 'Oh, this looks familiar,' and he thought that mammal-killing killer whales killed this," Filatova told Live Science. But for it to be an orca fin was a surprise.

Two years later, in July 2024, he found a second dorsal fin from an orca. This one was a bit bigger, from a young male, but it had the same killer whale tooth marks on it.

"At that moment, I started thinking that this is a pattern," Filatova said. The fins are tough and not good to eat and prevent a predator from eating the muscle and blubber under it, so killer whales discard them, she added. Genetic tests revealed that the fins came from resident orcas in the North Pacific.

Filatova and her colleagues think the resident orcas were probably attacked and eaten by Bigg's orcas.

"At least now we know that cannibalism happens, but I think it is not super common," Filatova said.

The researchers suggest that such occasional predation by the mammal-eating Bigg's orcas is a reason the resident orcas form large, close-knit family groups. Animals that aggregate in large groups or herds often do it to protect themselves from predators.

Orcas are generally thought to have no natural predators, but they have been known to be aggressive toward each other. In 2016, for example, Bigg's orcas were witnessed chasing and killing a newborn, potentially to force the mother to become sexually receptive. They didn't eat the calf, though.

Teaming up as a defense also may help to explain observations of large groups of resident killer whales chasing away smaller groups of Bigg's killer whales, Filatova said. She noted that, in her own work, she has seen evidence of Bigg's orcas avoiding groups of resident orcas and returning to an area only after the residents had moved on. "So, it looks like this defense strategy is really working," she said.

But not everyone is convinced. "I think the observations of tooth marks on fish-eating whale carcasses are interesting and the idea is worthy of further investigation, but there's not yet enough evidence to build a solid account of the social evolution of fish-eating orcas," Luke Rendell, a biologist at the University of St Andrews in Scotland who wasn't involved in the study, told Live Science via email.

Rendell said the potential benefits of foraging together and passing on specific habitat and prey knowledge could also be important drivers for creating large groups tied to certain locations.

Other animals have also been suspected of forming tight-knit groups to defend against orcas. For example, pods of long-finned pilot whales (Globicephala melas) are also known to confront and drive away killer whales ‪—‬ a behavior that is largely attributed to their highly social nature. And orcas sometimes flee when they hear the calls of pilot whales.

"The similarities between short-finned pilot whale social structure and resident killer whale social structure, and the similarities in how they apparently respond to Bigg's killer whales, do suggest they may both be responding to potential predation pressure," Michael Weiss, research director at the Center for Whale Research in Washington, who wasn't involved in the research, told Live Science via email.

"I certainly think it's possible that Bigg's killer whales predated on these two whales," he said. But he added that scavenging by Bigg's killer whales or aggression from other resident killer whales while they were still alive also could have caused the rake marks on the washed-up dorsal fins. Therefore, it doesn't definitively show cannibalism or predation, Weiss said.

Filatova acknowledged that scavenging can't be ruled out, because orcas are known to have fed on whale carcasses from whaling. But she said fresh killer whale carcasses typically sink fast, making them inaccessible, and they only start floating a few days later, when they start to decompose. "You need to be really hungry to eat this," she said.

Filatova also doesn't think the marks on the fins are related to fights with other residents, because those marks tend to be on the animals' sides, she said.

She thinks predation pressure drove the formation of tight-knit social groups in resident orcas perhaps 100,000 years ago, after killer whales that had been evolving separately in the Pacific and Atlantic started to bump into each other; because the social structure proved efficient, it stuck.

However, she pointed out that eating another orca may not seem like cannibalism to these marine mammals, and there are calls to name them as separate species. "They never socialize; they never spend time together. For them, it's just another whale. So why not eat it?" Filatova said.

Editor's note: This article was updated at 6.53 a.m. ET on March 9 to correct an error that stated the fins belonged to southern resident orcas. The fins were from resident orcas in the North Pacific.

Orca quiz: Will you sink or swim?

China's Yangtze River is showing signs of recovery following the introduction of a 10-year ban on commercial fishing in 2021. The number of large fish has increased, and there has been recovery among endangered animals, including the Yangtze sturgeon (Sinosturia dabryanus) and the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), new research finds.

"These results show that strong political decisions are required to restore biodiversity," Sébastien Brosse, an ecologist at the University of Toulouse in France and co-author of the new study, told Live Science via email. "This is an encouraging message because biodiversity loss is often seen as irreversible." The Yangtze is the longest and largest river in China. About 30% of the country's population lives within its drainage basin, and the 11 provinces and municipalities that make up the Yangtze River Economic Belt generate about 47% of China's total gross domestic product.

But rapid urban development since the 1950s, dam building, decades of overfishing, pollution and habitat degradation had all led to a decline in water quality and a biodiversity crisis. The Yangtze River dolphin (Lipotes vexillifer) and the Chinese paddlefish (Psephurus gladius) went extinct, and 135 fish species found in historical surveys disappeared.

This decline continued despite the establishment of a network of protected areas and an investment of more than $300 billion in water-quality management and improvement. In response, China took drastic measures: The country instituted a 10-year fishing ban across the entire Yangtze basin in 2021, used river police to enforce strict penalties, and continued broad environmental management.

To assess the effects of the fishing ban, Yushun Chen, a hydrobiologist at the Chinese Academy of Sciences in Wuhan, China, and his colleagues used data from between 2018 and 2023 to evaluate the health of fish communities in the Yangtze before and after the ban went into effect.

They found that overall, the total mass of fish collected in samples more than doubled between those dates, and there was a 13% boost in the number of species in the samples.

The overall number of fish stayed about the same, but larger-bodied species that are higher up in the food web, including the economically valuable black Amur bream (Megalobrama terminalis) and the white Amur bream (Parabramis pekinensis), grew, and they contributed a larger amount of the biomass. However, the total mass of smaller species sampled decreased by 18%.

The team's findings, published on Thursday (Feb. 12) in the journal Science, also included positive signs for migratory and endangered species. For example, populations of slender tongue sole (Cynoglossus gracilis) increased after the ban, and its freshwater migration extended farther upstream. Endangered fish species — such as the Yangtze sturgeon, Chinese sucker (Myxocyprinus asiaticus) and tube fish (Ochetobius elongatus) — also showed signs of recovery.

Another notable positive was the boost in numbers of the only freshwater mammal remaining in the Yangtze River, the Yangtze finless porpoise (Neophocaena asiaeorientalis asiaeorientalis), whose population rose by a third from 445 in 2017 to 595 in 2022. This gain may have resulted from a greater availability of bigger fish to eat; fewer deaths related to vessel strikes or fishing bycatch; and a reduction in other stressors, such as underwater noise from vessel propellers, the researchers suggested.

"In an era of unprecedented biodiversity losses and declines, especially in freshwater systems, this study offers a glimpse of hope regarding the future of biodiversity," said Lise Comte, a conservation ecologist at California-based Conservation Science Partners who wasn't involved in the research.

"It demonstrates that bold protection and restoration strategies can be efficient in slowing down and even reverting human impacts on ecological communities," she told Live Science via email.

Chen and his colleagues are still monitoring Yangtze River biodiversity, and they said the recovery is continuing. But they warned that the progress could easily be reversed if commercial fishing were to restart and that lasting biodiversity recovery will depend on sustained management that addresses all human pressures on river systems.

They also suggested that similar conservation measures might be useful on rivers such as the Mekong and the Amazon.

However, the Yangtze fishing ban had huge human and financial costs, as it involved the recall of 111,000 fishing boats, the resettlement of 231,000 fishers, and an investment of more than $2.74 billion in the Yangtze River Economic Belt.

"The promising findings demonstrate the resilience of these systems but are also a case study of an approach that I hope we don't have to emulate elsewhere," co-author Steven Cooke, a professor of biology at Carleton University in Ottawa, Canada, told Live Science via email. "Closing all fisheries in a river basin has significant socio-economic consequences. Fishers, and those in related industries, often move on, forever changing those communities. Managing fisheries in ways that do not require such a 'nuclear' option is always preferred."

A better approach would involve the ongoing assessment of fish populations; science-based fisheries management; and the study of watersheds as integrated systems that connect people, water and fish, he added.

In March 2019, researchers off the coast of southwestern Australia witnessed a gruesome scene: a dozen orcas ganging up on one of the biggest creatures on Earth to kill it. The orcas devoured huge chunks of flesh from the flanks of an adult blue whale, which died an hour later. This was the first-ever documented case of orca-on-blue-whale predation, but it wouldn't be the last.

In recent months, orcas (Orcinus orca) have also been spotted abducting baby pilot whales and tearing open sharks to feast on their livers. And off the coast of Spain and Portugal, a small population of orcas has begun ramming and sinking boats.

All of these incidents show just how clever these apex predators are.

"These are animals with an incredibly complex and highly evolved brain," Deborah Giles, an orca researcher at the University of Washington and the nonprofit Wild Orca, told Live Science. "They've got parts of their brain that are associated with memory and emotion that are significantly more developed than even in the human brain."

But the scale and novelty of recent attacks have raised a question: Are orcas getting smarter? And if so, what's driving this shift?

It's not likely that orcas' brains are changing on an anatomical level, said Josh McInnes, a marine ecologist who studies orcas at the University of British Columbia. "Behavioral change can influence anatomical change in an animal or a population" — but only over thousands of years of evolution, McInnes told Live Science.

Related: Scientists investigate mysterious case of orca that swallowed 7 sea otters whole

But orcas are fast learners, which means they can and do teach each other some terrifying tricks, and thus become "smarter" as a group. Still, some of these seemingly new tricks may in fact be age-old behaviors that humans are only documenting now. And just like in humans, some of these learned behaviors become trends, ebbing and flowing in social waves.

Frequent interactions with humans through boat traffic and fishing activities may also drive orcas to learn new behaviors. And the more their environment shifts, the faster orcas must respond and rely on social learning to persist.

Teaching hunting strategies 

There's no question that orcas learn from each other. Many of the skills these animals teach and share relate to their role as highly evolved apex predators.

Scientists described orcas killing and eating blue whales (Balaenoptera musculus) for the first time in a study published last year. In the months and years that followed the first attack in March 2019, orcas preyed on a blue whale calf and juvenile in two additional incidents, pushing the young blue whales below the surface to suffocate them.

This newly documented hunting behavior is an example of social learning, with strategies being shared and passed on from adult orcas to their young, Robert Pitman, a marine ecologist at Oregon State University's Marine Mammal Institute, told Live Science in an email. "Anything the adults learn will be passed along" from the dominant female in a pod to her offspring, he said.

Taking down a blue whale "requires cooperation and coordination," Pitman said. Orcas may have learned and refined the skills needed to tackle such enormous prey in response to the recovery of whale populations from whaling. This know-how was then passed on, until the orcas became highly skilled at hunting even the largest animal on Earth, Pitman said.

Old tricks, new observations 

Some of the gory behaviors researchers have observed recently may actually be long-standing habits.

For instance, during the blue whale attacks, observers noted that the orcas inserted their heads inside live whales' mouths to feed on their tongues. But this is probably not a new behavior — just a case of humans finally seeing it up close.

"Killer whales are like humans in that they have their 'preferred cuts of meat,'" Pitman said. "When preying on large whales, they almost always take the tongue first, and sometimes that is all they will feed on."

Tongue is not the only delicacy orcas seek out. Off the coast of South Africa, two males — nicknamed Port and Starboard — have, for several years, been killing sharks to extract their livers.

Although the behavior surprised researchers at first, it's unlikely that orcas picked up liver-eating recently due to social learning, Michael Weiss, a behavioral ecologist and research director at the Center for Whale Research in Washington state, told Live Science.

Related: Orcas attacked a great white shark to gorge on its liver in Australia, shredded carcass suggests

That's because, this year, scientists also captured footage of orcas slurping down the liver of a whale shark off the coast of Baja California, Mexico. The likelihood that Port and Starboard transferred their know-how across thousands of miles of ocean is vanishingly small, meaning liver-eating is probably a widespread and established behavior.

"Because there are more cameras and more boats, we're starting to see these behaviors that we hadn't seen before," Weiss said.

Sharing scavenging techniques 

Orcas master and share more than hunting secrets. Several populations worldwide have learned to poach fish caught for human consumption from the longlines used in commercial fisheries and have passed on this information.

In the southern Indian Ocean, around the Crozet Islands, two orca populations have increasingly scavenged off longlines since fishing in the region expanded in the 1990s. By 2018, the entire population of orcas in these waters had taught one another to feast on longline buffets, with whole groups that previously foraged on seals and penguins developing a taste for human-caught toothfish.

Sometimes, orcas' ability to quickly learn new behaviors can have fatal consequences. In Alaska, orcas recently started dining on groundfish caught by bottom trawlers, but many end up entangled and dead in fishing gear.

"This behavior may be being shared between individuals, and that's maybe why we're seeing an increase in some of these mortality events," McInnes said.

Playing macabre games 

Orcas' impressive cognitive abilities also extend to playtime.

Giles and her colleagues study an endangered population of salmon-eating orcas off the North Pacific coast. Called the Southern Resident population, these killer whales don't eat mammals. But over the past 60 years, they have developed a unique game in which they seek out young porpoises, with the umbilical cords sometimes still attached, and play with them to death.

Related: 'An enormous mass of flesh armed with teeth': How orcas gained their 'killer' reputation

There are 78 recorded incidents of these orcas tossing porpoises to one another like a ball but not a single documented case of them eating the small mammals, Giles said. "In some cases, you'll see teeth marks where the [killer] whale was clearly gently holding the animal, but the animal was trying to swim away, so it's scraping the skin."

The researchers think these games could be a lesson for young orcas on how to hunt salmon, which are roughly the same size as baby porpoises. "Sometimes they'll let the porpoise swim off, pause, and then go after it," Giles said.

Are humans driving orcas to become "smarter"? 

Humans may indirectly be driving orcas to become smarter, by changing ocean conditions, McInnes said. Orca raids on longline and trawl fisheries show, for example, that they innovate and learn new tricks in response to human presence in the sea.

Human-caused climate change may also force orcas to rely more heavily on one another for learning.

In Antarctica, for instance, a population of orcas typically preys on Weddell seals (Leptonychotes weddellii) by washing them off ice floes. But as the ice melts, they are adapting their hunting techniques to catch leopard seals (Hydrurga leptonyx) and crabeater seals (Lobodon carcinophaga) — two species that don't rely on ice floes as much and are "a little bit more feisty," requiring orcas to develop new skills, McInnes said.

While human behaviors can catalyze new learning in orcas, in some cases we have also damaged the bonds that underpin social learning. Overfishing of salmon off the coast of Washington, for example, has dissolved the social glue that keeps orca populations together.

"Their social bonds get weaker because you can't be in a big partying killer-whale group if you're all hungry and trying to search for food," Weiss said. As orca groups splinter and shrink, so does the chance to learn from one another and adapt to their rapidly changing ecosystem, Weiss said.

And while orcas probably don't know that humans are to blame for changes in their ocean habitat, they are "acutely aware that humans are there," McInnes said.

Luckily for us, he added, orcas don't seem interested in training their deadly skills on us.

Orcas living off the coast of British Columbia in Canada have been spotted hunting with dolphins and sharing scraps of salmon with them after making a kill.

The northern resident population of orcas (Orcinus orca), or killer whales, off British Columbia has been observed teaming up with Pacific white-sided dolphins (Aethalodelphis obliquidens) in hunts for Chinook salmon (Oncorhynchus tshawytscha).

The researchers used underwater video, data from suction-cup biologging tags and aerial drone footage to establish how nine northern resident orcas moved and hunted in August 2020 — and how they interacted with Pacific white-sided dolphins around Vancouver Island, Canada.

They captured aerial and underwater footage of the animals' coordinated interactions. The two species in this area generally show few signs of mutual aggression and sometimes seek each other out, which is unusual given that orcas hunt dolphins in other locations, while some dolphins mob orcas.

The researchers recorded 258 instances of dolphins traveling near tagged orcas. In all these cases, the orcas were engaged in foraging-related behaviors, such as killing, eating or hunting for salmon, which are too large for dolphins to capture and swallow whole.

The researchers observed 25 instances of orcas changing course after encountering dolphins, after which both would dive down, potentially foraging. This may be a result of orcas listening out for dolphin echolocations, said study lead author Sarah Fortune, an oceanographer at Dalhousie University in Nova Scotia, Canada.

The authors also recorded eight instances of orcas catching salmon, breaking them up and sharing the pieces with other orcas. Dolphins were present on four of these occasions, and on one of them, the dolphins scavenged the conveniently broken-up salmon remains.

"The surprising thing for us is that knowing the resident killer whales are specialists in hunting Chinook salmon, the killer whales should really be the best ones at finding them, so why are they bothering to follow the dolphins?" Fortune told Live Science.

She said the findings are the first documented recording of cooperative hunting and prey-sharing between orcas and dolphins. The research was published in the journal Scientific Reports on Thursday (Dec. 11).

Researchers still aren't sure whether it is a cooperative system that both species benefit from equally, Fortune added. "We haven't been able to quantify the extent to which killer whales and dolphins obtain benefits from this interaction, but from our observations we see positive outcomes for both."

By associating with the orcas, the dolphins may also get protection from other populations of orcas that do hunt dolphins, she said.

"It's perhaps unsurprising, given the learning abilities of toothed whales, that these two species have learned that certain aspects of foraging in the same time and place bring advantages to both species," said Luke Rendell, a reader in biology at the University of St. Andrews in Scotland who wasn't involved in the study. "I find the risk management the dolphins have to do around killer whales is particularly impressive," he told Live Science by email, adding that if you hang out with the wrong orcas "you get eaten."

Scrounging for food?

Michael Weiss at the Center for Whale Research in Friday Harbor, Washington who wasn't involved in the research, noted he wasn't sure whether the observed behavior showed the two species working together.

"I'm not completely convinced that what we're seeing here is cooperative; it seems clear that the dolphins can benefit from reduced predation risk and scrounging from killer whale kills, but I think more work needs to be done to demonstrate a benefit to the whales," Weiss told Live Science by email.

Instead, the behavior might be kleptoparasitism ― one animal stealing food that another has already hunted — noted Jared Towers, the executive director of Bay Cetology, a cetacean research institute in Canada, who wasn't involved in the research.

"They provide evidence for the dolphins stealing fish scraps from the killer whale meals and that's really nice to see, because that's exactly what we thought has been happening all these years," Towers told Live Science.

He said the coordinated movements also support another hypothesis — the idea of orcas avoiding dolphins, not cooperating with them. "The killer whales take longer dives, they travel further underwater and they reduce vocal activity. To me, this suggests that the killer whales are trying to avoid the dolphins."

Fortune agrees other hypotheses are possible. "The dolphins might be the ones sneaking in and stealing the fish from the killer whales, like a kleptoparasite, but we have observations of dolphins going after salmon at the surface and on at least one occasion you see the dolphin catch a salmon, then it loses it, then tries to catch it again," she said. "It's clear that the dolphins want the salmon but they're not necessarily well adapted morphologically to capture those big fish."

Working with orcas would give the dolphins the means to actually get the fish, she added, while the orcas may be able to locate salmon more easily by following dolphins.

Fortune said further investigation of the relationship between these marine mammals is needed to understand how widespread and consistent any cooperative behaviors may be.

In recent years, orcas have been spotted getting up to all kinds of shenanigans, showing impressive levels of cultural learning. Members of the southern resident population near Washington and British Columbia have been seen wearing salmon on their heads and giving each other massages with kelp. And another group of the smart marine mammals has been damaging boats off the coast of Spain.

Orca quiz: Will you sink or swim?

Rare tusked whales have been identified and photographed alive at sea for the first time following a herculean research effort off the shores of Mexico, a new study finds.

The newly-sighted cetaceans are ginkgo-toothed beaked whales (Mesoplodon ginkgodens), which were previously only known from dead individuals that had washed ashore and from bycatch. This isn't all that unusual for beaked whales, which are deep divers and notoriously cryptic, spending their lives away from coastlines.

"Beaked whales are the largest least-known animals left on the planet," study co-author Robert Pitman, an affiliate of the Marine Mammal Institute at Oregon State University, told Live Science in an email. "It is exciting to think that there [are] still organisms here on earth that weigh over a ton and have never been identified alive in the wild."

The hunt for and subsequent discovery of the elusive creatures was sparked by a recording of a distinct echolocation pulse in the North Pacific. Researchers began searching for the animals responsible for the mysterious sonar signal in 2020, and in June of 2024, it led them to a single beaked whale. Within days of that sighting, the team then found a small group of the whales, including a battle-scarred adult male and adult female with a calf.

Beaked whale species can be difficult to tell apart, so simply observing the whales wasn't enough to identify them. The team only confirmed what they had seen after collecting a DNA sample by shooting one of the whales with a crossbow. (Don't worry, the whale is fine.)

The researchers published their findings online July 28 in the journal Marine Mammal Science, which will appear in the upcoming January 2026 issue of the journal. Study lead author Elizabeth Henderson, a bioacoustic researcher at the Naval Information Warfare Center, Pacific, said that the findings demonstrated the benefits of determination and not giving up.

"Myself and some of the other folks on this trip (Gustavo Cardenas, Jay Barlow) spent five years looking for these whales; we spent every year since 2020 searching off Baja to find them, and that effort and determination paid off with a huge reward," Henderson told Live Science in an email.

Ginkgo-toothed beaked whales are so named because the males have a pair of teeth that resemble the fan-shaped leaves of a ginkgo tree. For the whales, almost all of this shape is hidden in the jaw and gum tissue, with only the tip of each tooth visible on either side of their mouth. The teeth grow into small tusks as the males mature, and aren’t for eating, but are used as weapons.

"They feed on small squids and fishes by suction feeding, so they don’t need teeth," Pitman said. "As a result, females are toothless their entire lives, but males retain a single pair of enlarged teeth in the lower jaw that they use as tusks to fight over access to reproductive females."

When the team finally tracked down the whales, they saw that one adult male was seemingly battle-hardened with a worn tusk, bruising and scars. The other whales the researchers recorded across six separate observations were marked, too, and not just from other whales. Their scars included distinctive white blobs indicative of bites from cookiecutter sharks — little sock puppet-like fish that feed by ripping cookie-shaped chunks out of larger animals.

The team documented the whales with binocular observations, photographs and hydrophones (underwater microphones). During the fifth encounter, one of the whales swam within 66 feet (20 meters) of the stern of the researchers' ship, which is when Pitman fired his 150-pound (68-kilogram) draw-weight crossbow loaded with a modified punch-tip arrow.

"The crossbow arrow ('bolt') extracts a tiny, pencil-eraser-sized plug of skin and blubber," Pitman said. "We have collected thousands over the years, from dozens of whale and dolphin species."

Henderson compared the crossbow shot to an ear-piercing gun, while Pitman noted that any one of the whales' cookicutter shark bites probably took 50 times more tissue than the crossbow. The arrow didn't stick in the whale, so the researchers could retrieve it and the tissue. With a sample in the bag, the researchers then sent the tissue to a geneticist for testing.

"It took a few days to process the material and run the tests, and we were all waiting with [bated] breath," Henderson said. "When we got the results back we were all a bit shocked — while they did look like that species, this was not the expected area of their distribution so we had discounted that as a possibility — but we were also thrilled to finally have the mystery solved."

Ginkgo-toothed beaked whale strandings are fairly common in the western Pacific, but only two individuals have ever been recorded stranding in the eastern Pacific. The researchers had initially suspected that the whales they were seeing were Perrin's beaked whales (Mesoplodon perrini), which Pitman said are known from only six stranded specimens off southern California and are the least known marine mammals (and large animals) in the world.

Pitman noted that the team now hopes to go looking for Perrin’s beaked whales and the two other species of beaked whales that have yet to be identified alive in the wild, putting faces to more underwater calls.

"This is important because once we match up the calls to all the individual species, then we can use passive acoustic monitoring (towing hydrophones behind vessels, drifter buoys, etc.) and finally learn where these whales live, how many there are, and how vulnerable they are to human disturbances, especially high-seas fisheries," Pitman said.

Scientists in Norway have witnessed the birth of a baby orca in the wild, first-of-their-kind pictures show.

The researchers were observing a group of orcas (Orcinus orca) during a whale-watching trip off the coast of Skjervøy in the Arctic Circle when the water around the animals suddenly turned crimson with blood, they said.

"We were floating calmly and watching the feeding, when all of a sudden, close to the boat, there was blood spilling and splashing everywhere," Krisztina Balotay, a photographer and videographer at Orca Channel, a boat tour company that also gathers marine mammal data in Norwegian waters, wrote in a Facebook post on Nov. 2.

"At first, I had no idea what was going on," Balotay wrote in the post. "A moment later, I saw a little head pop above water. As it turned out, a female gave birth right next to us."

Moments after the calf was born, the rest of the group formed a protective circle around it. The orcas, mostly females and juveniles, were unusually energetic and seemed to be forcefully pushing the newborn toward the surface, which worried the team on the boat at first.

"We observed them carrying the calf on their back and holding it above water for air," Balotay wrote. "I was not sure if it was alive."

Scientists with the Norwegian Orca Survey, a research and conservation organization, flew a drone above the orcas to take a closer look. They also asked five other whale-watching boats that were on the scene to clear the area so the animals could calm down, representatives of the survey wrote in a Facebook post on Nov. 3.

Footage from the drone showed that the calf had struggled to stay afloat for the first 15 minutes after birth, but that it was alive and well after that.

"The mother was identified as NKW-591, a known female first identified in 2013," the representatives wrote. "She has had multiple offspring and is therefore an experienced mother."

The calf's dorsal fin was bent, but this is to be expected in the hours after a newborn emerges from the womb, Balotay noted in Orca Channel's post. "It was so amazing to watch something like this in the wild," she added.

This is the first documented case of an orca being born in the wild and of its first hour alive, Norwegian Orca Survey representatives wrote on Facebook. The team followed the orcas until darkness fell, maintaining a distance of more than 1,000 feet (300 meters) so as not to disturb the animals. "We also ensured the whales' space was protected by stopping additional boats from approaching," they said.

The Norwegian Orca Survey hope they will encounter this orca group and the calf again in the coming weeks. In the meantime, researchers will collate the data they collected during and after the birth for a study.

"Documenting calf survival remains one of the core objectives of our long-term research," they said.

Researchers have spotted orcas in the Gulf of California repeatedly attacking and feasting on the livers of juvenile great white sharks in first-of-their-kind observations.

The orcas (Orcinus orca) employed a savage-but-clever method to temporarily paralyze their prey, according to a new study. The technique involved flipping the small sharks upside down, thereby changing their awareness of their surroundings and forcing them into a trance-like state known as tonic immobility.

"This temporary state renders the shark defenseless, allowing the orcas to extract its nutrient-rich liver and likely consume other organs as well, before abandoning the rest of the carcass," study lead author Jesús Erick Higuera Rivas, a marine biologist and director of the nonprofit research organization Conexiones Terramar, said in a statement.

In three separate instances, the orcas were then observed sharing the shark livers among themselves. The attacks were carried out off the coast of Mexico by Moctezuma's pod, an orca group named after a large male member that made headlines last year for brutally slaying a whale shark (Rhincodon typus).

Orcas were already known to hunt great white sharks (Carcharodon carcharias) in some regions, including South Africa and Australia, but records of this behavior in the Northeast Pacific are extremely rare, with the last reliable sighting off the West Coast documented in 1997. Sightings in South Africa and Australia have primarily involved adult great whites, whose large proportions and organs mean more food for the orcas, according to the study.

There is only one previous report of orcas killing a juvenile great white shark. The attack happened in 2023 off the coast of South Africa by an infamous orca named Starboard; the predator gripped onto a young great white shark's pectoral fin, thrusting it forward several times before eviscerating the shark, according to the report.

The new observations, published Monday (Nov. 3) in the journal Frontiers in Marine Science, reveal that orcas attacking young great whites is more widespread than scientists thought.

"This is the first time we are seeing orcas repeatedly target juvenile white sharks," study co-author Salvador Jorgensen, a marine ecologist at California State University, Monterey Bay, said in the statement. "Adult white sharks react quickly to hunting orcas, completely evacuating their seasonal gathering areas and not returning for months. But these juvenile white sharks may be naive to orcas. We just don't know yet whether white shark anti-predator flight responses are instinctual or need to be learned."

Two of the three attacks took place in August 2020, according to the study. Five female orcas from Moctezuma's pod pursued one young great white shark until it tired, pushed it to the surface, and turned it onto its back. The orcas eventually forced the shark underwater, and when they reappeared, they were holding its liver in their mouths, the researchers described. Shortly after this kill, the orcas went for seconds, chasing and gutting a second young great white.

The third attack was in August 2022 and followed a similar sequence. Five orcas, including one adult male, flipped a young great white like a pancake, pushing it to the surface and biting it. Blood gushed from the shark's gills, and its liver protruded from its abdomen enough for the orcas to grasp it.

A closer look at where the sharks' injuries were suggested tonic immobility may minimize the orcas' chances of being bitten as the orcas try to extract the liver. Choosing juveniles as prey also limits the risk to orcas, but it's unclear if orcas in the Gulf of California only kill youngsters or if they regularly attack adult great whites, too.

"This behavior is a testament to orcas' advanced intelligence, strategic thinking, and sophisticated social learning, as the hunting techniques are passed down through generations within their pods," Higuera Rivas said.

One reason this behavior has been spotted now may be that great whites only recently started breeding in Mexican waters. Rising ocean temperatures and climate events such as El Niño appear to have shifted the distribution of great white shark nurseries, and Moctezuma's pod is likely taking advantage of an increased number of juveniles in the Gulf of California.

Other orca pods in the area could catch on, study co-author Francesca Pancaldi, a marine biologist at the National Polytechnic Institute in Mexico, said in the statement. "So far we have only observed this pod feeding on elasmobranchs [sharks and rays]," she said. "There could be more."

Orcas along the Spanish coast are attacking boats once again, leaving destroyed rudders and stranded crews in their wake.

A small population of orcas (Orcinus orca), or killer whales, has developed a penchant for damaging boats off the Iberian Peninsula in southwestern Europe in recent years. Researchers are still studying this behavior, but they think the orcas are likely being playful rather than aggressive.

On Aug. 21, orcas tore the rudder off a German sailboat in the Vigo estuary in Galicia, Spanish newspaper Faro de Vigo reported. The orcas then continued to play with the sailboat, which they rammed as it was towed to safety.

The Pontevedra Civil Guard, a Spanish law enforcement agency, shared a video of the sailboat rescue on the social platform X and wrote that the orcas had attacked several sailboats. It's unclear exactly how many boats were targeted prior to this post, but there have also been incidents since.

For instance, on Saturday (Aug. 30), Faro de Vigo reported that orcas destroyed a traditional wooden sailing ship's rudder off O Grove within the Arousa estuary and opened a leak in another sailboat off Ons within the Pontevedra estuary.

Valentín Otero, the owner of the ship targeted in O Grove, told Faro de Vigo that he heard two blows against his vessel before he spotted a pair of orcas. Otero and his crew reported that there was a larger orca measuring about 23 feet (7 meters) long accompanied by a smaller orca swimming alongside it.

"The truth is we were very frightened; in fact we completely freaked out when we realized the orcas were hitting the boat," Otero said in a translated statement.

Related: Watch a pod of orcas pretending to drown one of their own in macabre training session

The Iberian orcas are a critically endangered orca subpopulation thought to have fewer than 40 individuals. The group has been attacking boats off the coast of Spain and Portugal since 2020. While some initial reports suggested that Iberian orcas could be carrying out revenge against the ships, this has been dismissed by many orca experts.

The encounters often involve young orcas going straight for the rudders on the underside of sailing boats. Scientists have suggested that the orcas are likely just bored teenagers with more free time since Atlantic bluefin tuna (Thunnus thynnus) populations — their favorite prey in the region — recovered, meaning they need to spend less time hunting.

Orca behavior is diverse and complex. Researchers have observed the species engaging in intricate social rituals, from gently nibbling on each other's tongues to tumbling alongside each other as if they're in an aquatic mosh pit. Different orca populations also have their own dialects, similar to human language, and can develop their own unique "fads," such as swimming around with dead salmon on their heads.

There's no reason to suspect that the Iberian orcas are targeting the people aboard the boats. Orcas are fierce predators that are known to hunt a variety of different prey, from tuna to seals, sharks and even whales. However, each population has a particular diet, and none of them involves eating humans. There's only a handful of documented cases of wild orcas attacking humans, and all of these reported incidents come with significant caveats, such as an orca likely mistaking a person for a seal.

Scientists have discovered a "deceptively cute" ancient whale with large eyes and razor-sharp teeth that devoured prey off Australia around 26 million years ago.

The newly discovered Janjucetus dullardi is one of the earliest known cousins of filter-feeding baleen whales, including the gigantic blue whale (Balaenoptera musculus). However, J. dullardi was much smaller than its living relatives, with a compact body built for speed.

Researchers identified this new species from pieces of skull found on the coast of southeastern Australia. The individual it belonged to was a juvenile or subadult, around 7 feet (2.1 meters) long, according to a study published Tuesday (Aug. 12) in the journal Zoological Journal of the Linnean Society.

"It's essentially a little whale with big eyes and a mouth full of sharp, slicing teeth," study lead author Ruairidh Duncan, a paleontology doctoral student at the Museums Victoria Research Institute and Monash University in Australia, said in a statement. "Imagine the shark-like version of a baleen whale — small and deceptively cute, but definitely not harmless."

Related: Ancient whale 'graveyard' discovered under melting Russian glacier

J. dullardi belonged to a family of small whales called mammalodontids, which lived in warm, shallow waters off Australia and New Zealand during the Oligocene Epoch (33.9 million to 23 million years ago). This is not long, in evolutionary time, from when the ancient ancestors of today’s whales first returned to the ocean some 50 million years ago.

A school principal named Ross Dullard first spotted the J. dullardi fossils while walking along the beach of Half Moon Bay, near Melbourne, in 2019. The fossils were exposed at the base of a wave-eroded rock outcrop — part of a geological formation known as the Jan Juc Marl, which is between about 24 million and 28 million years old. After discovering the fossils, Dullard donated them to Museums Victoria.

"This kind of public discovery and its reporting to the museum is vital," senior study author Erich Fitzgerald, a senior curator of vertebrate paleontology at the Museums Victoria Research Institute, said in the statement. "Ross' discovery has unlocked an entire chapter of whale evolution we've never seen before. It's a reminder that world-changing fossils can be found in your own backyard."

Researchers used photography, microCT scans and other techniques to perform a detailed analysis of the fossils, which included preserved teeth and inner ear structures. The team deduced that J. dullardi was a previously unknown species of mammalodontid and named it after Dullard. One of the reasons researchers could tell it was a young whale was because of a lack of wear on the teeth.

Southeastern Australia has become a hotspot for ancient whale fossils, with two other mammalodontid species recovered from the Jan Juc Marl formation. Researchers continue to find fossils in this region and expect more discoveries in the years ahead, according to the statement.

"This region was once a cradle for some of the most unusual whales in history, and we're only just beginning to uncover their stories," Fitzgerald said.

Blue whales sing less when they are starving and sing more when food is plentiful, a recent study revealed. Researchers listened to whales off California for six years and found that their singing increased following a marine heatwave — despite multiple news outlets claiming that blue whales are going silent.

Whales have a range of vocalizations, but only the males sing. There's evidence of males using their songs to attract females and communicate with other males, said study lead author John Ryan, a biological oceanographer at the Monterey Bay Aquarium Research Institute in California. "It's an essential part of how they sense their world and interact with each other," he told Live Science.

The singing also provides researchers with an opportunity to study whales. Sound travels very well underwater, so in the vast ocean, listening for animals can be more efficient than looking for them, even when the animals you're looking for are the largest on Earth.

"We can see one of these whales if we're up close and at the surface, and it's at the surface, but we have to be very close," Ryan said. "In contrast, if one of those whales is anywhere within an area thousands of square kilometers around our hydrophone, we'll hear them."

In February, Ryan and his colleagues published a study in the journal PLOS One, which used hydrophones, or underwater microphones, to record the songs of blue (Balaenoptera musculus), humpback (Megaptera novaeangliae) and fin whales (Balaenoptera physalus) in the Monterey Bay National Marine Sanctuary. The team then compared the acoustics data to fisheries data from the National Oceanic and Atmospheric Administration (NOAA). The scientists found that whale singing fluctuates based on food availability and that whales sang less when food resources were scarce.

The study began in 2015 at the peak of a devastating marine heatwave known as "the blob." This heatwave disrupted the marine ecosystem and left whales starving. As a result, 2015 was the year researchers heard the least amount of whale song. However, when temperatures cooled and the marine ecosystem slowly recovered, the whales found their voices again.

Related: Creepy 'biotwang' noises coming from the Mariana Trench finally explained after 10 years

In July, National Geographic reported that blue whales are going silent, which has since been repeated by multiple news outlets citing the February study. However, while the amount of whale song in the study varied from year to year, all three whale species were singing more at the end of the study period compared with the beginning. In other words, the whales weren't going silent at all; they were getting louder — or at least, being heard more often after the heatwave.

Blue whale singing rose dramatically between 2015 and 2018, dropped between 2018 and 2020, and rose again in 2021. This singing trend tracked with rises and falls in the availability of their only prey, krill. The researchers believe that when food availability is low, the whales can't put as much energy into their singing.

"In the case of blue whales especially, they can't switch prey, so they simply have to search farther and wider for the only prey they eat," Ryan said. "We can imagine that if they have to dedicate much more time and energy to foraging, then there will be less time and energy available for other behaviors."

Chemical analysis of whale skin samples confirmed that blue whales searched farther and wider for krill when there were fewer available. In contrast, humpback whales switched between krill and fish (anchovies and sardines) depending on availability. As a result, they were the only whale species that saw a continuous rise in singing over the six-year period, according to the study.

"As food resources for whales changed throughout the six-year study period, humpback whales were found to be more resilient than blue whales," Ryan said. "This is because humpback whales have a more flexible foraging strategy, feeding on different types of prey," he added.

The study's findings were consistent with a 2023 study published in the journal Ecology and Evolution, which found a reduction in certain blue whale calls off New Zealand during regional marine heatwaves in the summers of 2016 and 2018. Both studies highlight the negative effects that marine heatwaves can have on whales.

Extreme marine heatwaves have tripled over the past 80 years, with additional widespread heatwaves in 2023 and 2024. The latest whale song study covered data collected up until June 2021, so it's currently unclear what has happened since. However, while the world's oceans are getting warmer due to climate change, the whales off California haven't "stopped singing."

Ryan said that they have continued to collect data since the end of the study period and are studying those numbers right now. When asked whether the blue whales have gone silent since 2021, he replied: "Nope."

Are blue whales in decline?

Blue whales are much rarer today than they were before modern commercial whaling decimated their populations in the early 1900s. Since then, blue whale hunting has been banned and their population has been increasing, according to NOAA. But most population estimates are a few years old.

A draft of the latest NOAA U.S. Pacific marine mammal stock assessment states that there are around 1,898 blue whales in the eastern North Pacific population — the blue whales that Ryan recorded singing off California. However, that estimate is based on data collected in 2018. The global population is estimated to be between 5,000 and 15,000 adults, according to the IUCN Red List of Threatened Species, but that figure is also based on a 2018 assessment.

Editor's note: This story was amended to clarify that whale skin sample analysis revealed the blue whales searched farther and wider for krill, their primary diet, not just that they continued to feed on them.

Orca moms teach their young how to pretend-drown each other, first-of-its-kind footage shows. The brutal training session teaches orcas the skills needed to kill the largest animal that has ever lived.

In the video, a young orca (Orcinus orca) pretends to be prey, letting the rest of the pod surround it and submerge its blowhole to prevent it from breathing. Members of the pod practice holding the young orca's head under the water for a while before releasing it.

Later in the clip, the pod applies this technique while hunting a blue whale (Balaenoptera musculus). The orcas appear to catch the whale off guard, giving them an advantage in what would otherwise be an unequal fight with the enormous whale. They crowd around the whale's head and submerge its blowhole, but it's unclear from the footage whether they succeed in killing the giant mammal.

While researchers already knew that orcas can kill whales by drowning them, "this practice-hunting behaviour has never been filmed before," a spokeswoman for the BBC, which filmed the footage for its new nature series "Parenthood," told The Times.

Related: Orcas filmed making out in the wild for first time

The clip is narrated by British biologist and broadcaster Sir David Attenborough. "These orca need to be on top of their game," Attenborough explains in the footage. "They hunt the largest animals that have ever lived: blue whales."

Filmmakers used specialized underwater stabilizing devices called gimbals and tow cameras to capture the scene off the coast of Bremer Bay in Western Australia. "This technology allowed the crew to travel at the same speed as the orca hunting pack and provided new insights into their behaviour," the BBC spokeswoman told The Times.

Bremer Bay is home to an orca population of about 200 individuals, which makes it the largest known congregation of orcas in the Southern Hemisphere, according to the tour operator Bremer Bay Killer Whales. Pods range in size from six to 20 orcas, and they typically eat giant squid (Architeuthis dux) and colossal squid (Mesonychoteuthis hamiltoni) rather than blue whales.

Orcas likely hunt blue whales not for food, but simply because they can and want to have fun, experts say. "They play with [whales] like cats play with their prey," Nancy Black, a marine biologist who runs the whale-watching business Monterey Bay Whale Watch, told National Geographic after drone footage of orcas attacking a blue whale emerged in 2017.

But going after a solitary adult whale is risky, so orcas usually chase blue whales that are sick or have their calves in tow. The calves tire more quickly than adult whales, falling behind and becoming easy prey for orcas, National Geographic reported.

The BBC show "Parenthood" is a five-part series about some of the strategies and behaviors used by animal parents that boost the survival of their young. In the U.S., the show is expected to air on PBS's "Nature" later this year or early next year.

"My personal favourite must be the story of the African social spider, a mother spider who not only raises 50 offspring alongside her sisters but eventually sacrifices her own body to feed her growing young in an act called matriphagy," Jeff Wilson, the series' director, told The Times.

You can watch a stomach-turning clip of this sacrifice here.

Orca quiz: Will you sink or swim?

Scientists have discovered that a glacier in the Russian Arctic is retreating extremely quickly — and its rapid retreat has exposed a graveyard of ancient whale bones.

The research expedition landed on Wilczek Island, in the far north of Russia, earlier this year to study permafrost, according to a statement from the Arctic and Antarctic Research Institute (AARI) in Russia.

Using satellite imagery, the team compared current and past positions of the glacier, Nikita Demidov, an AARI geologist, said in the statement. The scientists found that the ice cap on the island had split into two parts over a period of less than 20 years.

This glacier's decline is part of a wider shift — a study from February found that, since 2000, glaciers have lost about 5% of their ice globally.

Related: Dramatic transformation of the Arctic landscape may be permanent

The schism in the ice revealed several square miles of the island's surface, which held a large number of whale bones. Some of the skeletons are well preserved. Demidov noted that the bones are worst preserved near the seashore, where they have had longer to thaw, and are best preserved closest to the glacier.

"The paleontological find indicates an episode of extremely rapid sea level change in the area of the northernmost archipelago of Eurasia, which occurred in the last few thousand years," he said.

The expedition is being conducted from an Russian ice-strengthened vessel called Professor Molchanov and will continue through August, according to Russian state news agency TASS.

Wild orcas occasionally approach humans and offer us food, according to a new study — but scientists aren't sure why.

Researchers have documented dozens of cases of orcas (Orcinus orca), also known as killer whales, dropping prey and other sea life in front of people. In almost all of the encounters, the orcas then waited to see what humans would do with their offering, and sometimes tried to offer food more than once. These offerings included fish, some whale, birds, stingrays, seaweed and a turtle.

Researchers aren't certain what's driving this behavior, which was documented in different orca populations over a more than 20-year period. But orcas are known to share their food, according to the new study, published June 30 in the Journal of Comparative Psychology.

"Orcas often share food with each other — it's a prosocial activity and a way that they build relationships with each other," study lead author Jared Towers, the executive director of Bay Cetology, a cetacean research institute in Canada, said in a statement. "That they also share with humans may show their interest in relating to us as well."

The researchers offered a range of possible explanations for the behavior, suggesting that offering items to humans could provide opportunities for the orcas "to practice learned cultural behavior, explore or play," and potentially form relationships with us.

However, while the behavior seems altruistic, the researchers couldn't rule out that the orcas were trying to manipulate the people they approached — though it's unclear what the orcas are trying to achieve.

Erich Hoyt, a researcher at the charity Whale and Dolphin Conservation who was not involved in the study, told Live Science that the authors gave plausible reasons for the orcas sharing prey with humans.

"The study was done carefully, removing borderline cases, and the method was clearly explained," Hoyt, who also wrote "Orca: The Whale Called Killer" (Firefly Books, 2019), said in an email. "The authors are suitably careful about the conclusions and suggesting various explanations."

Related: Orcas filmed making out in the wild for first time

The researchers reported 34 sharing interactions from around the world, including off the coast of California, Norway and New Zealand. Towers and his colleagues included their own encounters with orcas, as well as those described to them in interviews. Some of the interactions were also caught on camera. The team only included interactions where the orcas approached humans of their own accord, when humans were in the sea, on boats or close to the shore, though the humans may have first put themselves in the vicinity of the orcas.

In most cases, humans ignored the orcas' offering. Some of the orcas then recovered the item and shared it with other orcas, and in a few cases, returned to offer it to the human again — even trying multiple times. On three occasions, humans returned the offering, and the orcas then offered it again, according to the study.

Orcas are intelligent and communal creatures that engage in complicated social rituals, from gently nibbling on each other's tongues to tumbling alongside each other in the marine mammal equivalent of mosh pits. This also isn't the first time orcas have interacted with people.

For example, an orca population used to hunt alongside Indigenous Australian whalers and European whalers in Australia. However, orcas got food out of those cooperative hunts, while in the new study, they were often giving it away without a clear motive.

They can also be incredibly playful animals and sometimes toy with food and other objects in their environment. For example, researchers have documented orcas tossing around and killing baby porpoises that they have no intention of eating. Some orcas famously have a penchant for attacking boats off southwestern Europe's Iberian coast, which again appears to have a playful component. However, the researchers found that the orcas in the new study usually weren't playing with the food they offered.

"With all the comments about orca play behaviour in relation to the Iberian orcas bending and breaking rudders of boats, it could be easy to dismiss these [offerings] as isolated incidents representing no more than another kind of play," Hoyt said. "But [the] authors point out that the provisioning/prey sharing happens equally between all sex and age classes, not just by the younger members who more actively engage in play."

Different orca populations have their own dialects, similar to human language, and can develop their own unique "fads," such as swimming around with dead salmon on their heads. The newly documented behavior wasn't confined to a specific population or location, but the researchers did find that it only involved orcas that typically hunt and share prey near the surface, which could help explain its origin.

All of the orcas documented in the study were generalist hunters, typically eating a range of air-breathing animals like whales, as well as fish usually found near the surface. None of the cases involved orcas that exclusively feed on fish, often at depths, despite some of these orcas being very familiar with people. Hoyt said this aspect of the study was fascinating but also logical.

"Salmon and other fish are often hunted singly, not cooperatively," Hoyt said. "The [orca] whales that hunt marine mammals, sharks and other larger prey are much more often sharing the large prey items they catch with their pods and not just because there’s plenty to go around."

Orca quiz: Will you sink or swim?

Dwarf sperm whales have an unusual way to protect themselves if they come under attack. When they feel threatened, these tiny whales release their intestinal fluid, turning the water red.

Growing up to 8 feet 10 inches (2.7 meters) long, they are the smallest species of whale. They are even smaller than some dolphins, such as Risso’s dolphins (Grampus griseus) which can reach 13 feet (4 meters) and bottlenose dolphins (Tursiops truncatus), which grow to around 12 feet (3.8 meters). These animals look so similar to pygmy sperm whales (Kogia breviceps) that it's challenging to tell the two apart. They were even believed to be the same species until 1966.

At the surface, they don't usually approach boats, which makes them very hard to study. The life of these toothed whales is typically unhurried. According to the Whale and Dolphin Conservation, they tend to travel at a steady pace, and drift gently back under the water when they’re ready to go back to deeper waters.

They only dive suddenly when they're startled. If this happens, they also release their intestinal fluid, potentially in defense or as a reaction to feeling nervous — like a squid releasing ink.

Related: Sperm whales drop giant poop bombs to save themselves from orca attack

No other whales, except pygmy sperm whales, use this tactic to escape from danger.

"Each dwarf sperm whale has a sac filled with dark liquid in its intestine," representatives from the National Oceanic and Atmospheric Administration Fisheries wrote. "The whale can release more than three gallons [11 liters] of dark, reddish-brown liquid — or ink — from this sac."

This cloud darkens the water, making it harder for the predator to see, which helps the tiny whale to make its getaway.

Their predators include large sharks and orcas (orcinus orca), and these pint-size whales are also threatened by entanglement, vessel strikes, and pollution.

Dwarf sperm whales can live to around 22 years old. Although little is known about their social behaviors, they are usually seen in small pods of no more than 16 whales.

They prefer deep waters and can dive to over 1,000 feet (300 meters) to find food. They eat a variety of deep-sea squid, octopus, crabs, and fish — using echolocation to track down their prey. They are often found near continental shelves where they have access to lots of their food sources.

For the first time ever, a pair of orcas have been spotted making out in the wild.

The amorous pair was observed nibbling each other's tongues during a snorkeling expedition in the Kvænangen fjords in northern Norway, around 68 miles (109 kilometers) northeast of Tromsø, according to a new study published June 11 in the journal Oceans.

This tongue-nibbling behavior has only previously been seen on a handful of occasions in captivity.

The action, described as resembling "kissing" by the citizen scientists who observed it, may play a role in social bonding, the researchers suggest.

The citizen scientists spotted and recorded this unique behavior during a whale-watching snorkeling expedition in October 2024. The interaction lasted just under two minutes and involved three bouts of gentle mouth-to-mouth contact between the two orcas (Orcinus orca). Afterward, the pair swam their separate ways.

Tongue-nibbling was first seen in captive orcas in 1978 and was described again in 2019 at Loro Parque, a zoo in Tenerife, Spain that houses three captive orcas.

The researchers spoke to a range of divers and other orca researchers regarding the behavior in the wild, but only a handful had ever spotted it. Trainers at Loro Parque noted that four individuals at the facility had been seen tongue-nibbling, but the orcas had not performed the behavior for several years.

"Tongue-nibbling is exceptionally rare," study co-author Javier Almunia, a marine mammal researcher and director of Loro Parque Fundación, told Live Science via email. "Orca caretakers at several facilities are aware of the behaviour, but its prevalence is extremely low — it may appear and then not be observed again for several years."

Mouth contact between animals is seen in a vast number of species and can represent a variety of different social cues. Many social animals use mouth contact to reinforce bonds, such as primates, who engage in kissing or lip-touching as a sign of trust and friendship. In dogs and wolves, mouth licking, especially from younger or subordinate individuals, can represent a sign of respect or submission to a higher-ranking individual.

The researchers suggest that tongue-nibbling in orcas may be a form of social bonding, similar to that seen in belugas (Delphinapterus leucas), a type of toothed whale.

"Tongue-nibbling itself has not been recorded in other species, but comparable mouth-related social interactions have been observed in belugas (e.g., mouth-to-mouth contact). This could suggest that, given cetacean anatomy — particularly the adaptation of limbs to the marine environment — oral contact may serve as a more versatile means of social communication than in terrestrial mammals," Almunia said.

"This behaviour appears to serve affiliative purposes and may play a role in reinforcing social bonds or resolving conflicts, akin to grooming or reconciliation behaviours in other highly social species," he added.

However, we cannot be certain of what exactly drove the orcas to exhibit this behavior without further research.

"We can only speculate on the function and nobody can know for sure without data relating it to known social structures in the wild (in captivity the 'social structure' is completely artificial and therefore largely irrelevant for understanding social function in evolutionary terms)," said Luke Rendall, a marine mammal researcher at the University of St. Andrews in Scotland. "It may be affiliative, it might be a form of begging, that is trying to stimulate food transfers, it might even be a form of grooming, somehow having a cleaning function," Rendall told Live Science.

The researchers suggest in the paper that the observed tongue-nibbling could be a "trend" play behavior in the orcas, similar to positioning dead fish on their heads as hats, which was seen in one orca population.

This observation of tongue-nibbling in the wild suggests that the behavior is not exclusive to captive animals and instead is found in a range of genetically distinct populations.

"Observing the same behaviour in wild orcas confirms that this is a natural behaviour retained in orcas under human care. This continuity supports the idea that behavioural studies in zoological settings provide important insights into the ethology of wild populations," Almunia said.

However, not everyone is convinced by the argument that captive animals can give insights into natural behavior and suggest far more research is needed to understand this tongue-nibbling.

"There’s no quantification here — no attempt to calculate actual rates by doing the hard work of pulling together numbers such as the number of hours observed in the wild per observation of this behaviour, and the same for captivity," Rendall said.

"Even if the behaviour itself is fascinating, and I think it is, we are limited on conclusions because it’s just one observation, but it is telling that in their summing up these authors take great pains to try and explain how this observation justifies the activities of [orca captivity and swim-with-cetaceans programmes]. It does not, in my view."

Orcas have been filmed making and using tools for what seems to be a pleasurable, massage-like experience.

The southern resident population of killer whales or orcas (Orcinus orca) lives in a region of the north-west Pacific Ocean called the Salish Sea, which borders Washington and British Columbia. This population exclusively eats fish, and its members are known for the bizarre fad of wearing salmon on their heads.

Now they have been seen doing something that's never been documented among marine mammals before.

Michael Weiss at the Center for Whale Research in Friday Harbor, Washington, and colleagues captured high-resolution drone footage of the orcas from above, and observed them breaking off sections of bull kelp (Nereocystis luetkeana), pressing the piece of stem against a partner and rolling it between their bodies, in what seems to be a grooming ritual.

Weiss and his colleagues believe it is the first example of tool manufacture by a marine mammal, the first known tool use in a wild animal that benefits two individuals at once, and the first time we've seen a non-human animal manipulating a tool with the core of its body rather than with an appendage. They reported their findings June 23 in the journal Current Biology.

"They'll use their teeth and the movement of their heads and their bodies to break off about a two-foot-long length of that kelp's stem, or stipe, then approach another whale and flip it onto their rostrum, or their kind of nose, and press that kelp against the side of their partner," Weiss told Live Science.

Related: Living lunch box? Iceland orcas are unexpectedly swimming with baby pilot whales, but it's unclear why.

"From there, they kind of maneuver their body to keep the kelp wedged between the two of them and they roll it back and forth, sometimes for just a few seconds, sometimes for up to 15 minutes," Weiss said.

Deborah Giles, an orca specialist at the non-profit SeaDoc Society who wasn't involved in the work, told Live Science: "It's super interesting behavior. This is purposefully creating the tool that they want to use."

Weiss's team has seen male and female orcas of all ages do this, across different social groups, or pods, in the southern resident community.

Animals tend to groom to reduce stress, keep themselves in good health and create and reinforce social connections, so is that why the orcas are doing this?

As highly social creatures, orcas might be expected to groom each other, Els Vermeulen, a cetacean specialist at the University of Pretoria in South Africa but wasn't involved in the work, told Live Science. "Despite the study being new and this specific behavior being reported for the first time, it comes as no surprise to me."

Weiss's team found that kelp rubbing occurs more between related individuals and those of a similar age. This is what would be expected if grooming correlated with strong social relationships, said Weiss.

The team also found that whales with more dead skin were more likely to be rubbing, so it could help with hygiene.

"When we talk about animal behavior, there's the function, or the fitness benefit the animal gets, and that will relate to health and wellness. But there's also the mechanism in the brain causing them to want to do this," Weiss said. "I think a lot of that is that it feels nice."

Some animals, including chimpanzees, birds and elephants, are known to make and use tools, but examples among marine animals are limited. Sea otters use stones to break open shellfish and dolphins have been spotted with sponges on their noses to help them forage, but they're not making these tools.

Yet kelp grooming isn't the only example of how orcas can manipulate their environment to create "tools." They have also been seen making waves to wash seals off ice floes so they can catch them.

The southern residents are the only population of orcas seen using kelp for grooming so far, but that may be because researchers normally observe orcas from boats and wouldn't be able to see the small pieces of kelp.

"I've often observed killer whales rolling around on each other from a boat. It makes me wonder if they've been engaging in this behavior all of that time," said Giles. "Drone imagery has created an opportunity for us to see into the lives of these animals in a way that has never been possible before."

As for the salmon hat fad, experts are still none the wiser. "We don't know why they do it," said Giles. "But it occurs when there's more abundant access to prey. It might just be that they're playing with their food. It might just feel good to put a salmon on your head."

But time could be running out to study these remarkable orcas. The southern residents are listed as an endangered population under the U.S. Endangered Species Act. At the last census there were only 73 of them, said Weiss, and if we lose those whales. "It's not just 73 whales gone," he said. "It's a set of cultural traditions and a society that is unique. We might never see this behavior again."

Orca quiz: Will you sink or swim?

One day in June 2022 Chérine Baumgartner, a researcher at the Icelandic Orca Project, was watching from a dinghy as a pod of killer whales fed on herring — when she noticed something very odd about what seemed to be a young member of the pod. "At first, we were like, 'Oh my god, this killer whale calf has a problem,'" she says. It was far tinier than normal and lacked an infant orca's characteristic black-and-pale-orange coloration. Baumgartner, now a Ph.D. student at the Swiss Federal Institute of Technology Zurich, suddenly realized she was seeing an entirely different species: a baby pilot whale. She and her team observed the pod for nearly three hours before weather conditions forced them back to land. They found the pod the next day, but the pilot whale calf was nowhere to be seen.

Scientists noticed orcas interacting with baby pilot whales off Iceland every year from 2021 to 2023. Each instance was short-lived and featured different individual pilot whales (dark-gray members of the dolphin family with a bulbous forehead) and different pods of orcas. Now, in a new study in Ecology and Evolution, Baumgartner and her colleagues describe the 2022 and 2023 incidents and posit three potential explanations: predation, play or parenting.

In all the sightings, a weeks-old pilot whale swam by a female killer whale in what scientists call an echelon position, with the young whale located beside and slightly behind the adult orca. In the 2022 and 2023 instances, the killer whales occasionally nudged the calf along. In 2023 a calf was seen swimming ahead of the group, possibly as if to run away — and at one point it was lifted, belly-up, out of the water on the back of an orca.

With the first possible explanation, the killer whales could have been keeping the young pilot whales around like a living lunch box; some orcas in Iceland are known to eat harbor seals and porpoises. But Baumgartner notes that these Icelandic killer whales are predominantly fish eaters and that they didn't display overtly aggressive behavior toward the pilot whale calves. So predation is less likely, though not impossible, she and her colleagues say.

Related: 'Incredible and rare' sight as endangered whale attacked by 60 orcas in brutal hunt

Alternatively, the killer whales could have been playing with the young whales or using them to practice hunting. Iceland's orcas often herd herring, and they could have been incorporating the pilot whale calves in their hunting games.

Finally, the killer whales could have been extending their parental instincts to the young calves. Whales and dolphins in the wild often care for the young of other members of their pod, and although it's rare, dolphins have adopted calves from different species. In the pilot whales' case, Baumgartner says, she wouldn't categorize the relationship as adoption because the interactions seemed to be short-lived. The young pilot whales would likely have died without milk, and none of the female orcas were lactating at the time.

These three possibilities also aren't mutually exclusive, she says. "It could be [that the orcas] encountered the pilot whale opportunistically, and some individuals played with the whale, and others tried to nurture it," Baumgartner adds.

The other conspicuously missing pieces of the puzzle are how, in each instance, the orcas came across a pilot whale calf in the first place and what happened to that calf afterward. "Was it lost or abandoned?" asks study co-author Filipa Samarra, principal investigator at the Icelandic Orca Project and director of the University of Iceland's research center on the Westman Islands. "Or did the killer whales actively approach to take the calf away?" The researchers also wonder if the calves escaped or died or were killed or eaten by the orcas.

Sarah Teman, a graduate student in ecology at the University of Washington, who was not involved with the new study, says her jaw dropped when she saw pictures of the pilot whales with the orca pods. Teman previously studied southern resident killer whales interacting with porpoises in the Salish Sea off British Columbia and Washington State. In that research, she observed interactions that may have been motivated by nurturing, hunting practice or "play" — and often ended up killing the porpoises. "It was fascinating to see such similar behaviors" in the Icelandic orcas, she says, adding that the animals' interactions with the pilot whales seemed to be largely driven by nurturing or play behavior, just as had been seen in the southern resident killer whales' interactions with porpoises.

Samarra also speculates that the unusual interactions off Iceland could be a result of climate change because pilot whales increasingly follow schools of mackerel moving into warmer waters that overlap with the killer whales' range. She hopes that, next summer, her group will finally observe how the young pilot whales get entangled with the orcas and what happens to them next.

This article was first published at Scientific American. © ScientificAmerican.com. All rights reserved. Follow on TikTok and Instagram, X and Facebook.

A gang of more than 60 orcas brutally attacked and killed a 59-foot-long (18 meters) pygmy blue whale, leaving a nearby whalewatching tour shocked, new video footage shows.

The dramatic incident occurred in Bremer Canyon, a marine park off the coast of Bremer Bay in Western Australia, on Monday April 7

The enormous group of orcas (Orcinus orca) can be seen hunting together and circling the endangered pygmy blue whale (Balaenoptera musculus brevicauda) in footage posted on Instagram by the tour company Naturaliste Charters. Eventually, the whale is seen floating dead at the ocean surface, the blood pouring from its mouth as the orcas tuck into their hard-earned meal.

"We witnessed an incredible and rare event yesterday as multiple pods of orcas successfully hunted a blue whale in Bremer Canyon," Naturaliste Charters representatives said in the caption of a Facebook post, sharing pictures of the unique event. "The intense ordeal lasted less than 40 minutes from when we first saw the blue at the surface to when the battle was over."

As the blue whale's fate was sealed, the orcas "celebrated with breaches and tail slaps," the representatives added.

This incident marks one of only a handful of times that orcas have been observed attacking a blue whale species, Naturaliste Charters representatives said.

Related: Orcas: Facts about killer whales

Orcas are highly intelligent and hunt in coordinated groups, often using complex communication and teamwork to take down prey far larger than themselves. They often use brutal tactics, having previously been seen creating big waves to wash seals off floating ice, working together to separate whale calves from their mothers and drown them, and even ripping out the livers of sharks.

"We're all still pretty shell shocked," marine biologist Jennah Tucker, who works for Naturaliste Charters and witnessed the recent incident, told ABC. "It was all over pretty quickly for such a big animal."

The whale was seen to be covered in bite marks and at one point was swarmed by as many as 30 of the orcas at once.

"We estimated about 60 orca involved, likely more than that," Tucker said. "We've confirmed five different family groups were involved. Quite often, many will move in once it's over. But in this case, we saw 20 to 30 animals at a time crowding around the whale to take it down."

Tucker also said that there were several juvenile orcas among the feeding frenzy, including one as young as a month old.

"They are involved from a young age — this calf has no teeth but stuck by mum's side," Tucker said.

Pygmy blue whales are a subspecies of blue whale, which is the largest animal on Earth. Regular blue whales can grow as long as 110 feet (34 m), while pygmy blue whales grow up to around 79 feet (24 m). While smaller than their cousins, pygmy blue whales are still longer than many other whales, including humpbacks and sperm whales. Orcas rarely grow longer than 32 feet (10 m).

Pygmy blue whales are mainly found in the Indian Ocean and the southwestern Pacific Ocean and tend to stay in warmer tropical and temperate waters. They are one of five subspecies of blue whale identified so far. Blue whales in general are listed as endangered by the International Union for Conservation of Nature (IUCN), while pygmy blue whales are listed by the IUCN as Data Deficient, and under the Australian Environment Protection and Biodiversity Conservation (EPBC) Act as endangered.

"We definitely do as much as we can to not be involved and to have no interference, but it's a very difficult thing to watch; it can be very brutal," Tucker said of the event. "Especially an animal we know is struggling to bounce back after whaling. Pygmy blue whales are endangered."

"It was very emotional but that's nature, it was quite a privilege to witness the event," she added.

Orca quiz: Will you sink or swim?

Dolphins live in almost every ocean, except most tend to avoid the cold waters in the Arctic and around Antarctica. Some also live in rivers, including the Amazon River in South America and the Ganges River in India.

Dolphins are technically classified as whales, but are different from their larger cousins in many ways. The largest dolphin species is the orca, which measures up to 32 feet (9.8 m) long, while the smallest species is the Hector's dolphin, which grows to only 4.8 feet (1.5 m) long.

Dolphins live and hunt in large social groups called pods, and they communicate with each other using high-pitched clicks and whistles. They are very intelligent because they have to work together to hunt down prey.

Dolphins also love to play. You can often spot them surfing waves, toying with seaweed, and even interacting with other species for fun. Some species can swim incredibly fast, with the short-beaked common dolphin hitting speeds of up to 37 mph (60 km/h) — about as fast as a car driving on city streets.

5 fast facts about dolphins

• Dolphins use tools to find food. Some dolphins cover their beaks with sponges while searching for food on the seafloor. Others use empty shells to trap fish.
• Dolphins live in social groups called pods. Pods usually have two to 30 dolphins, but some dolphins live in superpods of over 1,000 animals.
• Dolphins use a language of clicks and whistles, called echolocation, to track down their prey and create a mental map of their surroundings.
• Some dolphin species live in freshwater rivers, like the Amazon.
• Despite their name, killer whales (orcas) are actually dolphins.

Everything you need to know about dolphins

Dolphin pictures

Discover more about dolphins

—The weird reason dolphins drink each other’s pee

—Watch a huge megapod of acrobatic spinner dolphins in incredible, rare video

—Orcas: Facts about killer whales

Whales are a group of mammals that live in oceans. They include some of the largest animals on Earth. The blue whale is the biggest animal that has ever existed. Whales can be found in every ocean, with many species migrating long distances between their feeding and mating grounds, where they gather to have babies.

There are over 90 whale species. Some of the most famous whale species are humpback whales, sperm whales, blue whales and narwhals. Despite their name, killer whales — or orcas — are not whales. Instead, they are part of the closely related dolphin family.

Many whale species were hunted for their oil and other body parts during the 1800s and 1900s, and they almost went extinct. Even though this practice has been banned in most countries, some whale species still have very small populations and are considered vulnerable, endangered or critically endangered.

5 fast facts about whales

• Cuvier's beaked whales hold the record for the deepest-diving mammal. They can go nearly 10,000 feet (3,000 m) below the water's surface — about 10 times deeper than the Eiffel Tower is tall..
• Some whales, such as humpback whales, are known for their long and complex songs, sometimes lasting up to 22 hours.
• Whales are not fish, so they cannot breathe underwater. Instead, they use the blowholes on the top of their head to breathe air at the ocean's surface.
• Whales evolved from a deer-like land mammal called Pakicetus about 50 million years ago.
• A sperm whale's brain weighs about 17 pounds (8 kilograms) — about five times heavier than a human brain — making it the largest brain of any known animal.

Everything you need to know about whales

Whale pictures

Discover more about whales

—Humpback whales: Facts about the singers of the sea

—Will humans ever learn to speak whale?

—Why some whales go through menopause

A viral video appears to show a humpback whale gobbling up a kayaker off the coast of South America before quickly spitting him out again.

Adrián Simancas was kayaking with his father in the Strait of Magellan in Chile last Saturday (Feb. 8) when the whale burst out of the water and seemed to close its mouth around Simancas and his kayak. For a few seconds, the whale and Simancas disappeared beneath the waves.

"I thought I was dead," Simancas told The Associated Press (AP). "I thought it had eaten me, that it had swallowed me."

The whale didn't hold onto Simancas for long as he soon popped back up at the surface. Then, as the terrified kayaker treaded water, the whale hunched its spine and dove back down into the ocean. Simancas' father, Dell, caught the whole incident on video before assisting his son out of the water. The pair returned to shore unharmed, AP reported.

Related: Male humpback whale crossed 3 oceans for sex, inadvertently breaking distance record for species

Do humpback whales eat people?

Humpback whales (Megaptera novaeangliae) feed on small fish and crustaceans. To eat enough to sustain their massive size, the whales take stretchy mouthfuls of more than 5,000 gallons (23,000 liters) of seawater and filter out their prey across baleen plates — kind of like long hairy teeth that filter rather than bite. This strategy evolved for hunting small animals, not humans in kayaks.

Erich Hoyt, a research fellow at Whale and Dolphin Conservation in the U.K. and author of the Encyclopedia of Whales, Dolphins, and Porpoises (Firefly Books, 2023), told Live Science that the whale in the video almost certainly snapped up the kayaker by accident.

"It's not clear from the video whether the kayaker was entirely in the whale's mouth," Hoyt said. "He could have been partly inside but I'm sure the whale would have expelled him immediately."

This isn't the first time a whale has appeared to gobble someone up accidentally. In 2020, a similar viral video showed a humpback whale coming out of the water and closing its mouth around two kayakers in California. The kayakers were floating above a large swarm of fish when the whale came up, CBC reported at the time. The humpback immediately released the kayakers, who were unharmed in the incident.

In 2021, a lobster diver off Massachusetts estimated that he was in a humpback whale's mouth for 30 seconds before being spat out. Whale researchers suggested at the time that the diver may have also swam too close to the whale's food and been accidentally gobbled up with it.

Hoyt said that humans are too large to be swallowed by a humpback whale. Researchers have studied humpback whales with Cassin's auklet seabirds (Ptychoramphus aleuticus) in their stomachs, which were presumably accidentally swallowed. However, those birds are only about 9 inches (23 centimeters) long, Live Science previously reported.

While humpbacks don't eat people, they have occasionally injured humans when they've felt threatened. In 2020, a humpback mum — likely trying to protect her calf — charged swimmers in Australia and sent two to the hospital. However, the species is better known for occasionally saving other animals from predators like killer whales (Orcinus orca) than harming humans.

Killer whales

Simancas was talking to his father about killer whales shortly before the incident with the humpback whale took place (killer whales also live off the coast of Chile). He told AP that he thought the whale might have been a killer whale at first. However, even if that were the case, a human in the ocean has little to fear from a killer whale.

"There are no cases of a wild killer whale killing and eating a human either," Hoyt said.

Some orcas have a habit of attacking boats in southwest Europe, and the species has killed humans when kept in captivity, but there's only one confirmed case of a wild orca biting a human. That unlucky person was a surfer in California in 1972, who the orca probably mistook for a seal.

Stunning new footage captures the moment adult orcas carefully teach their calves how to hunt, demonstrating how to push a seal off a bit of ice before getting the young to give it a go themselves.

The clip shows a group of seven orcas — four adults and three calves — as they circle a seal on a tiny chunk of ice in western Antarctica’s Marguerite Bay. The lesson, which lasted over an hour, was filmed for the new PBS show "Nature: Expedition Killer Whale," which follows a remarkable group of pack ice orcas (Orcinus orca) that live off the coast of Antarctica.

"The biggest surprise was the careful, measured way in which the females kept the seal corralled close to the piece of ice without fatally injuring it, so that it would climb back out onto the ice," Leigh Hickmott, a whale biologist and science advisor for the show, who observed the encounter from a boat nearby, told Live Science in an email.

"This allowed the females to show the calves a number of different approaches to gain access to the seal, all in one teaching session," he said. The hunting techniques they taught the calves included "wave washing, tipping the ice, bubble blowing to flush the seal from under the ice and taking hold of the seal by its hind flippers to prevent injury from its teeth."

Related: Boat-ramming orcas may be using yachts as target practice toys, scientists suggest

In the footage, a female orca leads the lesson, demonstrating how to pull the seal off the ice by its tail, as the calves watch and learn. She lets the seal escape, and after it jumps back on the ice, the calves take turns practicing the technique — a behavior that's repeated over and over.

Orcas are highly intelligent apex predators. They are social, living in family pods, and hunt in packs. They're among the few species known to actively teach their young (and one another) different skills, which can result in innovative new behaviors.

The orcas observed in the clip, known as type B1 orcas, are known for their "wave-washing" hunting technique, where the pod works together to create large waves that knock seals from the safety of ice floes into the water.

The PBS show also reveals the first recordings of these orcas' calls to each other as they search for prey, coordinate hunts and share their catch.

Hickmott said the teaching sequence highlights the cultural transmission of knowledge between orcas and shows their ability to solve complex problems through teamwork.

"Remembering past experiences and honing techniques builds their effectiveness as predators and that by regularly allowing young inquisitive calves to participate in order to learn, they strengthen the pod's future capabilities and likelihood of survival," he said.

"Nature: Expedition Killer Whale" premieres on Wednesday, Feb. 12 at 8/7c.

► How to watch 'Expedition Killer Whale' — TV and streaming details for orca documentary

Orca quiz: Will you sink or swim?

An endangered orca is carrying a dead calf around on her head in a tragic repeat of behavior that made headlines six years ago.

Tahlequah, or J35, became famous in 2018 for embarking on what some scientists described as a "grief" tour, pushing her dead calf through the ocean for 1,000 miles (1,600 kilometers) until she eventually let go. She went on to successfully rear two other calves. But now, Tahlequah, part of a struggling group called the southern resident killer whale population, appears to be grieving another calf.

Researchers at the National Oceanic and Atmospheric Administration (NOAA) photographed Tahlequah carrying a dead newborn calf in Puget Sound off Seattle on Wednesday (Jan. 1).

"This is an unfortunate way to start the new year with the news that southern resident killer whale J35 has lost another calf and is again keeping it with her," Michael Milstein, an NOAA public affairs officer, said at a news conference on Thursday (Jan. 2). "She is of course known around the world for carrying her earlier calf for 17 days in 2018, which was heartbreaking at the time. It's that much harder to see now that she has lost another one."

Related: Orca calf refuses to leave a lagoon where its mother stranded and died off Vancouver Island

Southern resident killer whales (Orcinus orca) are listed under the U.S. Endangered Species Act and have been struggling for decades. Scientists have identified three main reasons for their decline: less prey — mainly Chinook salmon (Oncorhynchus tshawytscha); pollution; and boat disturbance, according to NOAA.

A 2017 study published in the journal PLOS One found that nearly 70% of southern resident killer whale pregnancies failed between 2008 and 2014, with one-third of those pregnancy losses occurring late in gestation or immediately after birth. The NOAA researchers who documented J35's latest calf believe that it only lived for about a week.

The team first noticed the new calf on Dec. 20, after citizen scientists spotted it, Brad Hanson, a wildlife biologist at NOAA's Northwest Fisheries Science Center, said at the news conference. Researchers noted that the calf was alive on Dec. 23, but they were immediately concerned about its health.

Tahlequah appeared to be pushing the calf — called J61 — around even when it was alive, and while the calf seemed to be viable at the time, something wasn't right. "When it was surfacing, it looked like it might be struggling," Hanson said.

When the researchers got out on the water again on Dec. 31, they noticed that the calf was missing and Tahlequah appeared to be pushing something around, which they later confirmed was the now-deceased J61.

Good news

While Tahlequah became famous for this behavior in 2018, she is not unusual. Orcas are one of several species of whale and dolphin that have been observed carrying dead offspring.

NOAA will continue to monitor Tahlequah's pod, which is called "J Pod." Despite the tragic events of the last week, they are hopeful for the pod's future, particularly as there was another birth this week.

"The better news to remember is that J35 has given birth to calves that have survived and give us hope for the population," Milstein said. "And at the same time that the team realized that J35's calf had died, they also saw a new calf in J Pod that is very much alive and looks healthy."

Endangered southern right whales can live twice as long as scientists thought, a new study shows. These whales often reach 130 years old, and may even reach up to 150 years old, the study found.

Southern right whales (Eubalaena australis) are found throughout the Southern Hemisphere but were heavily hunted until the 1960s, when the International Whaling Commission began to ban commercial whaling. People in the whaling industries considered them the "right" kind of whales to hunt because they move slowly, float when dead and have a high yield of lucrative oil and whalebones.

Previously, scientists thought southern right whales had a life expectancy of around 70 years. But these marine mammals are closely related to bowhead whales, and the longest-living mammal ever recorded was an Alaskan bowhead (Balaena mysticetus) estimated to be 211 years old.

"Given everything else we knew about the life history of these species, I hypothesized that they [the Southern right whales] should live longer," study co-author Greg Breed, a quantitative ecologist at the University of Alaska Fairbanks, told Live Science.

However, estimating the longevity of whales can be difficult.

Scientists typically use annular growth layers on teeth, which, like tree rings, are laid down yearly. Many baleen whales, however, do not have such growth layers. And even if they do, tissue wear and tear, and lack of samples could skew the estimation.

But a bigger challenge is that, commercial whaling only ended about 60 years ago. So whales older than that would have survived many decades of intense whaling to become centenarians. It's likely few individuals reached their full lifespans.

To get around these challenges, Breed and his team analyzed whale tracking data of southern and North Atlantic right whales (Eubalaena glacialis) collected over four decades. From 1979 to 2021, scientists led by Peter Best at the University of Pretoria in Cape Town surveyed female southern right whales on the south coast of Africa by photographing them each year. From this survey, the scientists behind the new study identified 2,476 female individuals, 139 of which had known birth years. Breed and his team used these data to construct a survivorship curve. They noted the age and rate at which an individual disappears from the population. From there, they could estimate the fraction of a population surviving to a certain age.

"It's the same thing that the Social Security Administration uses to evaluate how long someone, who's now 65, what their average lifespan would be from that point, rather than from birth," Breed said.

The researchers compared these results with the North Atlantic right whale records collected around the same time and made available by the North Atlantic Right Whale Consortium, a nonprofit conservation group.

The analyses, described in a study published Dec. 20, in the journal Science Advances, revealed that southern right whales have a median lifespan of 70 to 75 years. One in 10 individuals was predicted to survive past 130 years old, confirming Breed's initial hypothesis. In comparison, North Atlantic right whales have relatively short lives with a median lifespan of 22 years, and only a few survive past the age of 45.

"Not because they're biologically very different, but because they have been experiencing a much higher degree of anthropogenic or manmade mortality than the southern right whales," Breed said. North Atlantic right whales are frequently entangled in fishing gear, especially lobster pots and crab pots that are fixed on the bottom of the ocean, he said.

Even with the current estimate, southern right whales only live half as long as bowheads. The researchers think this is linked to the right whales living in places devoid of sea ice.

"There's reason to think that living in the ice could contribute to longer lifespan," Breed said. For example, Orcas (Orcinus orca) or killer whales, which hunt both bowheads and southern right whales, are very averse to going into sea ice. "So the bowheads could always get into the sea ice, and the killer whales wouldn't follow them," Breed said. As sea ice disappears, bowheads may no longer be able to avoid predation.

Understanding an animal's lifespan affects the way we think about conservation, especially their reproduction pattern and their potential longevity post-whaling, Breed said. In the future, he and his team would like to investigate the population of old individuals that survived whaling and study how whale populations recover to pre-whaling levels.

Name: Chungungo, or marine otter (Lontra felina)

Where it lives: Rocky marine coastline from northern Peru to the islands of Cape Horn in Chile, and Isla de los Estados in Argentina

What it eats: Crustaceans, mollusks, fish, and occasionally birds and small mammals

Why it's awesome: Meet the chungungo — also known as the marine otter and sea cat — the smallest sea otter in the world.

The chungungo rarely grows beyond 45 inches (114 centimeters) in length and weighs just 6.6 to 11 pounds (3 to 5 kilograms). Its elongated body and small, flattened head give it a streamlined silhouette for swimming. But despite being well-adapted to the water, the chungungo only spends about 20% of each day in the water because of the frigid temperatures.

Unlike river otters, marine otters aren't great at regulating their body temperature. To retain heat they have to boost their metabolism, which requires them eating huge quantities of food — up to a third of their body weight each day. They also spend a lot of time lying on their backs, soaking up the sun, and diligently groom their coats to maintain their insulating properties.

Their highly vascularized feet also allow them to regulate their body temperature — spreading their toes helps cool them down, while closing them up conserves warmth.

The chungungo's short limbs are equipped with strong claws and webbed toes, ideal for catching prey. They use their tails and hind limbs to propel themselves through the water and are often found swimming on their backs. This position allows them to hold prey against its chest and manipulate it with its rear limbs.

Related: Lion-size otters prowled Ethiopia 3 million years ago

Chungungo fur, once heavily coveted by the fur trade, is dark brown on the back and yellowish on the belly. Beneath the outer coat lies a dense layer of fine hairs that insulate it from the cold and protect it from injury against the rocky coast. Marine otters live in extreme conditions — the rocky coasts they inhabit experience extreme swells and strong winds, while the cliffs are often steep, with their dens built into crevices and caves.

Chungungo pups are known for their curiosity and playfulness. During their breeding season (December to January), adults select a mate and remain together for life. In these monogamous partnerships, both parents share the responsibility of bringing prey back to the den to nourish their offspring.

Females give birth to one to three pups, which stay with their mothers for 8 to 12 months. Then, they separate from their parents and lead a solitary life, until they form a pair during the reproductive season.

A male humpback whale crossed at least three oceans in search of sex, a new study shows.

The whale's journey is the longest great-circle distance between two sightings ever recorded for the species (Megaptera novaeangliae), scientists said. Great-circle distance refers to the shortest distance between two points on Earth as measured on the planet's spherical surface.

Beginning off the coast of Colombia in the eastern Pacific Ocean and ending off the coast of Zanzibar in the southwest Indian Ocean, the whale's odyssey took it 8,106 miles (13,046 kilometers) across the globe, the researchers said.

The whale likely swam eastward from Colombia, riding on prevailing currents in the Southern Ocean and potentially visiting humpback whale populations in the Atlantic Ocean, said study co-author Ted Cheeseman, a doctoral student at Southern Cross University in Australia and director of Happywhale, an image database where the researchers collected evidence for the study.

"This was a very exciting find, the kind of discovery where our first response was that there must be some error," Cheeseman told Live Science in an email. Together with the astounding mileage, one of the most important findings from the study was that the whale dropped in on several humpback whale populations along the way, exploring farther afield than any other humpback whale known to science, Cheeseman said.

Related: Watch heartbreaking footage of humpback whale with missing tail in Washington state

Humpback whales usually follow very consistent migration patterns, moving between feeding grounds in cold waters near the poles and breeding areas closer to the tropics. The whales are known to swim more than 5,000 miles (8,000 km) in the north-south direction every year, but they don't tend to travel far in the east-west direction and generally don't mix with other populations.

The cross-ocean journey observed in the new study shows that humpback whale migrations are more flexible than researchers previously thought. While scientists have occasionally recorded similar migrations before — such as the case of a female humpback whale that swam 6,100 miles (9,800 km) from Brazil to Madagascar between 1999 and 2001 — the male in the new study has set a new distance record while traveling from one breeding area to another.

"We've been able to document novel behavior which provides important insight into [humpback whales'] ecology," study lead author Ekaterina Kalashnikova, a biologist working with the Tanzania Cetaceans Program and the Barazuto Center for Scientific Studies in Mozambique, told Live Science in an email.

The discovery is based on photographs the researchers took between 2013 and 2022, and which they subsequently posted on Happywhale. The pictures showed the same sexually mature male in two locations off Colombia, and then five years later in the Zanzibar Channel, each time in the company of a competitive group — a group of whales in which a female is closely guarded by a male "principal escort" and other males compete for access to her, Kalashnikova said.

The motivation for the journey was probably sex, with the male in question increasing his chances of reproducing by mingling with members of another breeding population. Other reasons for the whale's unusual adventure could be to do with environmental shifts that impact the distribution of food; climate change; and humpback whale population growth, which boosts competition between males during the feeding and breeding seasons, according to the study.

The research was published Tuesday (Dec. 10) in the journal Royal Society Open Science.

A gang of orcas off the coast of Mexico have learned how to hunt whale sharks — the world's largest shark species — and their tactics are brutal.

One male individual was present at the majority of these hunting events, researchers say, suggesting he may be driving this predatory behavior.

"The animals have shown us over and over again that they are extremely good at developing highly specialized strategies to target specific prey," Volker Deecke, a professor of wildlife conservation at the University of Cumbria in the U.K., told Live Science in an email. "This is a fascinating behaviour." Deecke specializes in marine mammal biology but was not involved in the new study.

Whale sharks (Rhincodon typus) are the largest fish in the sea, weighing up to 40 tons (36 metric tons) and usually growing up to 40 feet (12 meters) long, according to the National Ocean Service. The largest of these ocean giants can reach lengths of over 60 feet (18 m) — about as long as a bowling lane.

In comparison, orcas (Orcinus orca), also known as killer whales, rarely surpass 32 feet (10 m), according to the National Oceanic and Atmospheric Administration (NOAA) Fisheries. However, researchers have discovered that these formidable predators have developed strategies to take down the marine mammoths. The findings were published Nov. 29 in the journal Frontiers in Marine Science.

The researchers characterized this new hunting behavior by analyzing photos and video footage from the southern Gulf of California, taken between 2018 and 2024. They observed four such hunting events in total.

Related: Orcas start wearing dead salmon hats again after ditching the trend for 37 years

The orcas started by hitting the whale sharks at high speeds, in order to stun them and turn them upside down. In this position, the sharks were unable to move or escape into deeper water, study co-author Jesús Erick Higuera Rivas, a marine biologist at non-profit research organization Conexiones Terramar, said in a statement.

The orcas then attacked the whale sharks' pelvic area, causing them to bleed out and giving the orcas access to the sharks' nutrient-dense livers.

The researchers didn't actually see the orcas eating their livers, but the organ is known to be a favorite delicacy among orca pods elsewhere.

In three of the four recorded events, a large male adult orca called Moctezuma engaged in the group hunt. The fourth event was orchestrated by females that had previously been spotted with Moctezuma, suggesting he may have been teaching these tactics to other members of the pod. However, this theory has yet to be confirmed.

It is also unclear whether this is a new behavior or if it has been going on for years without detection. "More likely the increase in human activity (and availability of affordable waterproof cameras) has meant that a rare behaviour that has been present for some time is more likely to be detected (and recorded)," Deecke said.

"Studies across the globe have shown that individual killer whale groups and populations specialize on a few prey types that they hunt using very specialized hunting techniques. The fact the animals in the Gulf of California have evolved a strategy to attack and consume whale sharks is therefore not that surprising, but fascinating nonetheless."

Northwest Pacific orcas have started wearing salmon hats again, bringing back a bizarre trend first described in the 1980s, researchers say.

Last month, scientists and whale watchers spotted orcas (Orcinus orca) in South Puget Sound and off Point No Point in Washington State swimming with dead fish on their heads.

This is the first time they've donned the bizarre headgear since the summer of 1987, when a trendsetting female West Coast orca kickstarted the behavior for no apparent reason. Within a couple of weeks, the rest of the pod had jumped on the bandwagon and turned salmon corpses into must-have fashion accessories, according to the marine conservation charity ORCA — but it's unclear whether the same will happen this time around.

Researchers think the orcas sporting salmon hats now may be veterans of the trend when it first appeared nearly 40 years ago. "It does seem possible that some individuals that experienced [the behavior] the first time around may have started it again," Andrew Foote, an evolutionary ecologist at the University of Oslo in Norway, told New Scientist.

Related: Orcas are learning terrifying new behaviors. Are they getting smarter?

The motivation for the salmon hat trend remains a mystery. "Honestly, your guess is as good as mine," Deborah Giles, an orca researcher at the University of Washington who also heads the science and research teams at the non-profit Wild Orca, told New Scientist.

Salmon hats are a perfect example of what researchers call a "fad" — a behavior initiated by one or two individuals and temporarily picked up by others before it's abandoned. Back in the 1980s, the trend only lasted a year; by the summer of 1988, dead fish were totally passé and salmon hats disappeared from the West Coast orca population.

Orca researchers' best guess is that salmon hat fads are linked to high food availability. South Puget Sound is currently teeming with chum salmon (Oncorhynchus keta), and with too much food to eat on the spot, orcas may be saving fish for later by balancing them on their heads, New Scientist reported.

Orcas have been spotted stashing food away in other places, too. "We've seen mammal-eating killer whales carry large chunks of food under their pectoral fin, kind of tucked in next to their body," Giles said. Salmon is probably too small to fit securely under orcas' pectoral fins, so the marine mammals may have opted for the top of their heads instead.

Camera-equipped drones could help researchers monitor salmon hat-wearing orcas in a way that was not possible 37 years ago. "Over time, we may be able to gather enough information to show that, for instance, one carried a fish for 30 minutes or so, and then he ate it," Giles said.

But the food availability theory could be wrong — if the footage reveals that orcas abandon the salmon without eating them, researchers will be sent back to the drawing board.

Whatever the reason for the behavior, Giles said it's been fun to watch it come back in style. "It's been a while since I've personally seen it," she said.

Whale, hello there! Welcome to our orca quiz. You may be familiar with their distinctive black-and-white pattern and tall dorsal fins, but how much do you really know about these majestic marine mammals? For instance, did you know that orcas are actually the largest member of the dolphin family?

Renowned for being ruthless apex predators, they put the 'kill' in killer whale. Along with their large size and strength, orcas are terrifyingly intelligent which makes them formidable hunters. Orcas go after their prey in coordinated group attacks, earning them the nickname the "wolves of the sea." They have been documented killing blue whales, devouring great white sharks, and even ramming boats. Despite these behaviors, orcas are generally not dangerous to humans.

There is a softer side to orcas too, as they're a very social and family-orientated species (fun fact: the orca society is a matrilineal one). They've been known to display distinct personality traits (like playfulness and affection) and even have best friends. There have also been cases of orcas expressing grief and caring for each other.

Now that you know a bit more about these incredible creatures, can you match their smarts?

Take our science quiz and sea. If you need a hint, hit the yellow button!

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A solitary dolphin in the Baltic Sea appears to be talking to himself, potentially because he's lonely, according to a new study.

Bottlenose dolphins (Tursiops truncatus) are social animals that typically live in pods. But, in September 2019, a solitary dolphin, known as Delle by the locals, started hanging around the Svendborgsund channel, south of Funen Island, Denmark. This area is outside bottlenose dolphins' usual range, and no other dolphins were seen nearby.

Researchers had put down underwater recording devices to see how the presence of the solitary dolphin affected harbor porpoises. They were shocked when they heard Delle making so many noises. "Out of curiosity, I decided to add a recorder that captures actual sounds," lead author Olga Filatova, a cetacean biologist at the University of Southern Denmark, told Live Science via email. "I thought we might pick up a few distant whistles or something along those lines. I certainly didn't anticipate recording thousands of different sounds."

Over 69 days between Dec. 8, 2022 and Feb. 14 2023, the researchers detected 10,833 sounds, including several usually related to communication. These included 2,291 whistles, 2,288 burst-pulses — a rapid series of clicks sometimes associated with aggression — 5,487 low-frequency tonal sounds and 767 percussive sounds. The findings were published in a new study on Oct. 31 in the journal Bioacoustics.

Among these noises, the dolphin produced three distinctive whistles. "Bottlenose dolphins have what are known as signature whistles, believed to be unique to each individual, much like a name," Filatova said. "If we hadn't known that Delle was alone, we might have concluded that a group of at least three dolphins was engaged in various social interactions."

Related: Dolphins are 'literally acting like jerks' by beating up baby manatees

Filatova wasn't expecting to hear any vocalizations, certainly not noises associated with communication. "These sounds are traditionally considered communicative, meaning there should be at least two dolphins 'talking' to each other. But Delle was completely alone," she said.

At first, the scientists wondered if the dolphin might be trying to communicate with a local paddleboarder, but they also recorded the sounds at night time. "There were definitely no humans in the water," Filatova said.

For other experts, the results aren't entirely shocking. "Dolphins are very vocal animals, so I'm not overly surprised that this individual was still making sounds despite being alone," Thea Taylor, managing director at the Sussex Dolphin Project, who wasn't involved in the study, told Live Science via email.

"Dolphins rely on sound for key activities such as hunting and to sense their surrounding environment," she said, adding that they also use sound to communicate over large distances.

Why the solitary dolphin was so vocal remains a mystery. He could have been talking to himself or they might have been involuntary sounds triggered by a certain emotion, "much like how we sometimes laugh when we read something funny, even if no one else is around to hear," Filatova said.

Another theory is that he was calling out in the hope of attracting the attention of other dolphins nearby. "Though this seems unlikely," she said. "He had already spent three years in the area and would likely know by now that no other dolphins are present."

For Taylor, the idea that the dolphin's vocalizations may be involuntary emotional signals was the most intriguing element of the study. "This opens up so many questions about whether we can utilize dolphin communications to understand more about their behavior and emotions in the wild," she said.

Researchers don't usually record the sounds made by solitary dolphins. "They're seen as outcasts, as oddities, and no one truly expects them to produce any sounds worth documenting," Filatova said.

However, there is still much more to learn. "We still have some way to go before we fully understand why dolphins make the various sounds in their repertoire," Taylor said.

Researchers have finally identified the source of mysterious noises coming from the deepest ocean trench. The odd sounds, described as "biotwang" noises, sound a bit like sci-fi starships, and are actually whale calls from Bryde's whales (Balaenoptera edeni). The whales may use the calls to locate one another like a giant game of Marco Polo, researchers say.

Scientists first detected the unusual noises in 2014 while using underwater gliders to carry out an acoustic survey of the Mariana Trench — the world's deepest ocean trench, which spans more than 1,500 miles (2,400 kilometers) south of Japan and has a maximum depth of 35,876 feet (10,935 meters).

The biotwang sound can be broken down into two distinct parts: first, a low, grumbly sound that reverberates through the deep; and second, a high-pitched, metallic ringing that researchers have likened to the sounds made by spaceships in Star Trek and Star Wars.

The sounds initially stumped scientists. But in 2016, researchers revealed that biotwang was most likely a call from large baleen whales, such as blue whales (Balaenoptera musculus) or humpback whales (Megaptera novaeangliae). However, the sounds did not match any known whale calls.

In the new study, published Wednesday (Sept. 18) in the journal Frontiers in Marine Science, researchers were finally able to prove that Bryde's whales were making the noises, thanks in part to new artificial intelligence (AI) tools that sifted through over 200,000 hours of audio recordings containing various ocean sounds.

Related: Hidden DNA found in blue whales reveals they've been mating with other species — and their hybrid offspring

Researchers strongly suspected that Bryde's whales were behind the biotwang when they spotted 10 of the cetaceans swimming near the Mariana Islands and recorded nine of them making the distinctive noise.

"Once, it's a coincidence. Twice is happenstance. Nine times, it's definitely a Bryde's whale," study lead author Ann Allen, an oceanographer at the National Oceanographic and Atmospheric Administration's (NOAA) Pacific Islands Fisheries Science Center, told Scientific American.

But to conclusively prove that the Bryde's whales were the ones making the calls, the team matched the occurrence of the noises to the migration patterns of the species, which meant sorting through years of audio recordings captured by monitoring stations across the Mariana Archipelago and its surroundings.

They sped up that process by using AI to turn the biotwang into images, known as spectrograms, that could be easily differentiated from other noises by a machine learning algorithm.

The study also found that biotwang could only be heard in the northwest Pacific, despite Bryde's whales roaming across a much wider area, suggesting that only a specific population of the whales is making the noise.

The data also showed a spike in biotwang noises during 2016, when a rise in ocean temperatures caused by an El Niño event caused an increase in the number of Bryde's whales visiting the area.

It is still unclear why these calls sound so bizarre but researchers have a hunch over why they are being made.

"It's possible that they use the biotwang as a contact call, a sort of 'Marco Polo' of the ocean," Allen told Popular Science. "But we need more information before we can say for sure."

A dolphin attacking swimmers in Japan is probably lonely and sexually frustrated, experts say.

At least 18 people have been injured in dolphin attacks in Fukui prefecture this year in what is becoming an annual occurrence in the region. Most of the injuries are minor bites, but some beachgoers have suffered broken bones since the attacks started in 2022.

Researchers believe a lone male Indo-Pacific bottlenose dolphin (Tursiops aduncus) is likely responsible for the attacks based on photographs and video footage, Nature reported.

"We've seen that this dolphin randomly shows up at a beach, bites if there are people around, wanders off and repeats," Tadamichi Morisaka, a professor in the Cetacean Research Center at Mie University in Japan, told Nature. "To me, he's seeking some kind of interaction with people."

Dolphins engage in gentle biting with each other as part of their normal social behavior, so the dolphin might believe he's got a friendly relationship with the humans, Morisaka said.

"If he really wanted to attack, he could have come tackling at full force and chomped down. But he's keeping the biting gentle for dolphin standards, so it's probably a friendly gesture rather than a full-on attempt to attack," he said.

Related: Dolphins are 'literally acting like jerks' by beating up baby manatees

It's unclear why the dolphin is on his own. Bottlenose dolphins usually live in pods, with males forming long-term partnerships with other males. Paired males bite, chase, rub and engage in sexual behaviors such as pressing their penises against one another as part of these relationships, and Morisaka believes the dolphin in Fukui is trying to treat humans like a male pair mate.

Ryoichi Matsubara, the director of Echizen Matsushima Aquarium in Fukui, told The New York Times that the dolphin was observed trying to press his genitals against people in 2022 and 2023, and that he might be acting out mating behavior — but also biting beachgoers if they approached or tried to touch him.

Other researchers have also suggested that the attacks could partly be the result of the dolphin's desire to mate. Simon Allen, a principal investigator at the Shark Bay Dolphin Research project in Western Australia, told BBC News that dolphins can express their sociality in physical ways.

"Just as in humans and other social animals, hormonal fluctuations, sexual frustration or the desire to dominate might drive the dolphin to injuring the people it interacts with," Allen said. "Since they are such powerful animals, this can lead to serious injury in humans."

Fukui prefecture authorities are discouraging people from interacting with the dolphin. They've put up signs and fliers warning beachgoers, introduced lifeguard patrols and are limiting swimming hours on certain beaches, the Times reported. Authorities have also installed underwater acoustic devices emitting high-frequency noises to deter dolphins.

However, Morisaka is concerned the dolphin could get used to the acoustic devices and instead wants to develop an echolocation detection system to alert beachgoers that a dolphin is nearby. He believes that with people out of the water, the dolphin won't find anything interesting at the beaches and will eventually leave them alone.

If the human-dolphin interactions continue, they could become more dangerous. Morisaka said dolphins can begin attempting to assert their dominance over humans, engaging in aggressive behaviors such as tackling or mounting.

"We saw a bit of this last summer, so I was very concerned," Morisaka said. "They are about 2.5 metres [8.2 feet] long and weigh around 200 kilograms [440 pounds], so if they came charging at 20-30 kilometres per hour [12 to 19 mph], it'd be like getting into a traffic accident."

Scientists have a new theory to explain why orcas are ramming yachts in the Iberian Peninsula — the boats are practice targets for learning to hunt their favorite food.

When young Iberian orcas (Orcinus orca) started hitting and sinking boats in 2020, experts wondered whether it was revenge, accidental, or just a fun thing to do. But the new theory suggests the juvenile orcas might be using the boats' rudders as targets to practice hunting Atlantic bluefin tuna (Thunnus thynnus).

Since 2020, the sailing community has been, understandably, highly interested in the predators' whereabouts. "We saw that as a great opportunity for science," study lead author Bruno Díaz López, director of the Bottlenose Dolphin Research Institute (BDRI), told Live Science. The team realized they could use citizen science to gather accurate data about the orca population's distribution. "The sailors aren't going to be lying to each other because it's quite a serious problem," he said. Nearly half (47%) of the study's 597 records of killer whale occurrences related to vessel interactions.

Using this data, the team created computer models of the orcas' movements to fill knowledge gaps around their seasonal movements. Their models showed that the orcas and tuna are driven by the same environmental factors, meaning that knowing where the tuna are located gives you a good idea where the orcas will be. They discovered seasonal shifts in the orcas' preferred habitats, which align with the tuna's migration.

Related: A really big shark got gobbled up by another, massive shark in 1st known case of its kind

The findings were published June 18 in the journal Ocean and Coastal Management.

Orcas are highly specialized predators, and different communities prefer different prey, depending on the most abundant food available. Iberian orcas "really depend on tuna," Díaz López said.

Atlantic bluefin tuna are no longer endangered thanks to conservation measures to protect them from overfishing. Their recovery makes it easier for the Iberian orcas to find food, giving them more leisure time. "If you eat well, you have more time to play," Díaz López said.

And this play might give them the opportunity to practice useful skills. Orcas have to work together to catch tuna, as the fish can weigh hundreds of pounds, swim in large schools and are among the fastest fish in the sea.

To isolate an individual tuna and get it away from the protection of the group, the orcas ram, Díaz López said. "Maybe one orca hits, and then the other one hits again," he said. Once the orcas have separated an individual tuna, they tire it out and drive it towards shallower waters where it's easier to catch.

From reports of the killer whales' behavior towards sailboats, Díaz López believes the orcas are performing similar actions as they would during a hunt: repeatedly ramming the fast-moving rudder before trying to bite it. "To play is to learn," he said. "If you have a dog and you use a toy, the dog is learning a hunting technique."

Erich Hoyt, a researcher at marine charity Whale and Dolphin Conservation, who was not involved in the study, agrees that the orcas are likely playing. The interactions are most likely due to "normal predator curiosity leading to play behavior," he told Live Science via email. However, he's not convinced the boats are just target practice.

"I don't believe the orcas are playing with the rudders just to refine their hunting skills for tuna," he said. "I think their play is more like kids' play, without a set goal but which, in effect, helps building cognitive and physical skills."

To prevent further negative encounters, Hoyt recommends sailors monitor the orcas' movements and stay away. "The more the activity happens, the more it gets reinforced to continue," he said.

He believes this behavior is a phase that will eventually fizzle out. "In our limited experience we have seen that fads disappear over time," he said.

A whale whose tail appears to have been torn off by fishing debris has been spotted off the coast of Washington state. While the whale is managing to adapt right now, it will likely die from exhaustion and starvation soon, experts say.

Aerial drone footage shows the humpback whale (Megaptera novaeangliae) missing its iconic lobed fluke, which is responsible for propulsion while swimming.

"It's very disturbing," Jessica Farrer, lead responder and research director at The Whale Museum in Friday Harbor, told Live Science. "It's such a big majestic animal and it's missing a very important part of its body and on some level we know that we are the ones — humans that is — that caused it."

Related: Whale with broken back spotted near Mexico after suspected ship collision will likely die

The whale likely lost its tail fluke because of long-term entanglement in fishing lines or other debris.

"Their flukes are massive and our oceans are full of lines so it's not uncommon at all for humpbacks to pick up line and trail with it," Farrer said.

The whale, which has been named Catalyst, was first seen on July 5 on the east side of Swindle Island, then again on July 10 near Campbell River, according to a Facebook post from San Juan County Marine Mammal Stranding Network — a program run by The Whale Museum.

On July 23 it was spotted again off the coast of Lopez Island when a drone recorded the humpback whale using its pectoral fins to push itself along, before the whale revealed its missing fluke as it attempted to dive.

Despite its injury, Catalyst has traveled a distance of around 370 miles (600 kilometers) since the first sighting.

"It was traveling at a normal speed, around 3-4 knots [3.5 to 4.5 mph, or 5.5 to 7.5 km/h], it was diving and it was doing what humpbacks do, and it managed to make it from Campbell river all the way down to the San Juan islands," Farrer said. "Talk about the little whale that could."

Whales rely on their tail fluke for communication with other whales in the form of tail slaps, and for propulsion during deep dives to forage for food.

While it can swim, "it's likely not able to forage efficiently enough to sustain itself and has zero hope of migrating so it will probably stay within the region," Farrer said.

Without a tail fluke, the whale will likely die due to starvation or exhaustion, Farrer said, but added the marine mammal might adapt to its new swimming technique in the meantime.

"Initially the whale will start to scull [propel itself] with its pectoral flippers but eventually it will start using its peduncle [the muscle where the tail fluke connects to the body] in a kind of side to side motion," Farrer explained.

Entanglement is a threat to large whales worldwide. According to estimates from The International Whaling Commission, 300,000 whales die from entanglement in fishing gear each year.

Orcas have rammed a sailboat off the coast of Brittany — a whopping 800 miles (1,300 kilometers) north from the Strait of Gibraltar, where the majority of orca attacks on boats have occurred.

The incident occurred July 16 off the coast of Guilvinec, a commune 40 miles (65 kilometers) southeast of Brest in northwestern France. The couple on board lost control of their boat — a 40-foot-long (12 meters) wooden pleasure craft — after two young orcas (Orcinus orca) broke the rudder, local newspaper Le Télégramme reported.

The couple alerted the local coastguard, who towed the sailboat safely back to harbor in Guilvinec.

The incident is one of nearly 700 physical interactions between orcas and boats recorded since July 2020 along the Atlantic and Mediterranean coasts of Europe and North Africa. Roughly half of those interactions caused mild to serious damage to the boats, according to a translated report published earlier this year in the journal Ingeniería Civil.

Orcas almost always target the rudder, which they have learned to break off with ruthless efficiency.

Research and observations have linked these interactions to a population of about 35 Iberian orcas. A total of 16 animals from this population — four adults and 12 juveniles — are thought to interact regularly with boats, but their motivation remains unclear.

Related: Orcas are learning terrifying new behaviors. Are they getting smarter?

One hypothesis is that these orcas are bored "teenagers" looking for fun. But some scientists argue that interacting with boats is a freak behavior that emerged in response to a traumatic event.

"We think that there are arguments that indicate that an incident caused by an entrapment, in which a sailboat is involved, is feasible as a cause of psychological trauma that provokes a response on the part of a wild animal with high cognitive abilities, such as the orca," researchers wrote in the recent report.

The same team previously suggested that a female orca called White Gladis suffered a "critical moment of agony" and that she started ramming boats as a result. "If this hypothesis were true, the rest of the juvenile orcas would repeat the behavior by imitation," they wrote in the report.

It's unclear which population of orcas was behind the recent ramming off the coast of France. Iberian orcas follow their favorite Atlantic bluefin tuna (Thunnus thynnus) prey north from the Strait of Gibraltar to the Bay of Biscay in the summer, meaning they may have been hunting off the coast of Brittany.

But a different population also inhabits waters off west Scotland and northwest Ireland, where a case of an orca attacking a boat was reported last year. One expert at the time said the boat-ramming behavior could have "leapfrogged" from one population to the other.

A mysterious dead whale that recently washed up on a New Zealand beach may belong to the world's rarest cetacean species, spade-toothed whales, which are so elusive they have never been seen alive. If this is the case, the newfound specimen will give scientists a rare chance to study the creatures we know next to nothing about.

Beachgoers discovered the 16.5-foot-long (5 meters) carcass July 4 on the shore near Taieri Mouth — a village in the Otago region of New Zealand's South Island. Wildlife experts from the country's Department of Conservation (DOC), recovered the remains and took DNA samples, which have been sent to the University of Auckland for analysis, according to a DOC statement.

Researchers from DOC and the Museum of New Zealand Te Papa Tongarewa believe the animal is a spade-toothed whale (Mesoplodon traversii). However, they will not know for sure until the DNA samples are analyzed, which could take "several weeks or months," DOC representatives said. The remains are currently being preserved in cold storage.

Spade-toothed whales belong to a group known as beaked whales, which look like a mix between whales and dolphins. Beaked whales are the deepest-diving mammals on Earth and are capable of holding their breath for hours at a time, which makes them extremely hard to find and track.

If confirmed, the newly washed-up whale will be the sixth known spade-toothed specimen found in the last 150 years, of which only two others have been fully intact. To date, there have been no confirmed live sightings of the species.

"Spade-toothed whales are one of the most poorly known large mammalian species of modern times," Gabe Davies, a DOC coastal operations manager for Otago, said in the statement. "From a scientific and conservation point of view, this is huge."

Related: 10 creatures that washed up on the world's beaches in 2023

Spade-toothed whales were officially described in a 2002 study, which revealed that three whale bones found in New Zealand and Chile between 1873 and 1993 shared the same DNA that was unknown to science. The first intact specimens were found in 2010 when a suspected mother and calf washed up dead at Opape Beach in New Zealand's North Island.

Almost nothing is known about the species. However, researchers believe they probably share characteristics with other beaked whales from the genus Mesoplodon, such as extremely rare Sowerby's beaked whales (Mesoplodon bidens), which spend most of their time diving in the deep sea to hunt for squid, according to Whale and Dolphin Conservation (WDC).

Spade-toothed whales likely live exclusively in the Southern Hemisphere and are probably only found in the South Pacific Ocean, according to WDC.

If the new specimen is a spade-toothed whale, this will be the first chance that researchers have to dissect the species because the other intact specimens that washed up at Opape Beach were buried before genetic analysis confirmed their identity, AP News reported — meaning the opportunity to study them was lost.

Any dissection of the specimen will be carried out under the supervision of the local rūnaka — a Māori tribal council, DOC representatives wrote. This will be done to honor a non-legally-binding treaty signed by Māori leaders and several Polynesian Indigenous groups in March, which recognizes whales as "legal persons."

Rabid seals in South Africa are attacking people in the first known major outbreak of the disease among marine mammals. 

Eleven seals have so far tested positive for rabies in Cape Town. The animals are usually playful toward humans, but the outbreak is leading seals to act strangely and aggressively, alarming surfers and beachgoers, experts say.

Rabies is a deadly viral disease primarily transmitted through saliva that affects the central nervous system. Symptoms include fever, pain and tingling, pricking or burning sensations at the wound site, according to the World Health Organization. Unless medical attention is given immediately after exposure, the virus spreads to the central nervous system and leads to fatal inflammation of the brain and spinal cord. Symptoms can take anywhere between a week and two years to appear, but they usually occur one to three months after exposure. 

The last recorded case of a seal contracting the disease was in 1980 in Norway's Svalbard islands, The Guardian reported July 11. The new upsurge in cases is thought to be the world's first significant outbreak of rabies in marine mammals, but it's unclear how the disease entered the seal population.

South African fur seals (Arctocephalus pusillus) began behaving strangely a few years ago, Gregg Oelofse, the coastal manager for the City of Cape Town, told The Guardian. A spike in reported seal attacks in late 2021 suggested the animals were acting more aggressively than usual toward humans, he said.

Related: Watch great white shark get mobbed by gang of seals in 'incredible and surprising' footage

Together with scientists and animal welfare experts, Oelofse and his team captured and tested a few animals through 2022 to determine the cause of this sudden aggression. But given there was only one previous known case of rabies in seals, the team did not test for the disease, so they were left stumped.

The answer only came earlier this year, when a seal bit at least three surfers in a matter of minutes in the waters off Muizenberg beach, 12 miles (19 kilometers) south of Cape Town's city center. "This little seal came up at me at high speed," one of the surfers said in a video posted on Facebook in May. "It lurched onto my back and bit a hole into my wetsuit over here and kind of bit me on the backside."

The seal then latched onto the man's surfboard and started biting it, the surfer said. "Eventually it let go, but then it kept coming back at me all the time," he said. 

Around the same time, a seal was also seen swimming ashore with bloody injuries on its face likely inflicted by another extremely aggressive seal, according to The Guardian. Together with the attack at Muizenberg beach, this prompted authorities to euthanize four seals and test them for rabies.

Tests showed that three of the four seals were infected with rabies, and the number of reported cases has since grown to 11 along Cape Town's 190-mile-long (300 km) coastline, CNN reported July 12.

Despite daily contact between seals and surfers, the disease seems to have remained in the seal population. "We think quite a few people have been bitten by rabid seals, but luckily no human has got infected yet," Oelofse told The Guardian. The reason for this is unknown, he said.

Swimmers and surfers are nevertheless advised to exercise extreme caution and to seek immediate medical attention if a seal bites them. 

Surfers used to enjoy interacting with seals, which are curious and playful creatures. "But now everyone was paddling as fast as they could to get away," Oelofse said. While people should avoid seals that are behaving strangely or showing signs of aggression, there is no reason to fear animals that appear relaxed, he added.

Scientists are now sequencing the rabies virus to pinpoint where and when it entered the seal population and to determine how far it has spread. South African fur seals form dense colonies, meaning the disease could become endemic and eventually spread to other mammals, such as African clawless otters (Aonyx capensis), The Guardian reported. 

More than 80 pilot whales have died after mysteriously becoming stranded on a beach in Scotland. The mass stranding of the entire pod is thought to be the biggest the country has seen in nearly 30 years.

Locals reported the stranding to rescuers around 10:45 a.m. local time (5:45 a.m. ET) on Thursday (July 11), according to a statement from the British Divers Marine Life Rescue (BDMLR). The scene unfolded on a beach on Sanday, in the northern Scottish archipelago of Orkney. The stranded animals were long-finned pilot whales (Globicephala melas), which are actually large dolphins named after their unusually long pectoral fins.

By the time rescuers arrived later that day, 77 pilot whales had already been lying dead for several hours, their carcasses strewn high up across the beach, according to the statement. Twelve pilot whales were still alive, and the rescuers immediately performed health assessments and first aid.

But as the day drew on, the pilot whales' health took a dramatic plunge. Rescuers hoped the survivors would be able to swim off at high tide, but their efforts to refloat the animals were fruitless.

"The substrate they're on is also incredibly soft, meaning they have sunk even deeper into the sand when the tide washed over them, so they unfortunately weren't able to refloat themselves," BDMLR representatives wrote in the statement.

Related: Could an impending rise in solar storms cause more whales to strand?

The pilot whales may also have inhaled water with the incoming tide, worsening their condition, according to the statement.

As evening approached, rescuers and medics decided the animals couldn't be saved. "Sadly, the remaining 12 pilot whales have been euthanized due to their condition deteriorating from the many hours they have spent stranded on the beach," representatives wrote in an update just after 18:00 p.m. local time (13:00 p.m. ET).

It's unclear why the pilot whales stranded themselves, but it's possible that one pilot whale ran into trouble and consequently led the rest of the pod too close to the shore, the BBC reported. The pod was composed of large males up to 22 feet (7 meters) long, as well as smaller females, calves and juveniles, according to the BBC. 

Post mortem examinations may soon reveal what led the pilot whales astray. Experts with the Scottish Marine Animal Stranding Scheme (SMASS) will try to recover as many bodies from the beach as possible to conduct a thorough examination of the stranding, BDMLR representatives said in the update.

Large strandings like this one are becoming increasingly common in Scotland, Andrew Brownlow, a veterinary pathologist who leads the SMASS strandings team, told the BBC. "It used to be quite unusual to have a mass stranding event," he said. "But over the last 10 years or so we have seen an increase both in the number of mass stranding events around Scotland and also the size of the mass and the number of animals that it involves."

The cause is unclear, he said, but it could be due to there being more animals at sea, or because those animals are exposed to more hazards.

Orcas are hunting sharks in the Gulf of California, targeting large species including bull sharks and blacktips, scientists reveal.  

Three orcas, or killer whales, are behind the attacks, and researchers say it is unclear what impact these hunts could have on the ecosystem, and whether sharks will eventually decide to leave the area. 

In a new study published June 4 in the journal Frontiers in Marine Science, scientists recorded three instances of orcas (Orcinus orca) preying on sharks between 2022 and 2023 in the Cabo Pulmo National Park (CPNP), a marine protected area in the Gulf of California, Mexico. 

"The events described here represent the first documented predator-prey interactions between orca and sharks within the boundaries of the marine protected area of CPNP," the scientists wrote. 

On Jan. 9, 2022, a drone filmed six orcas patrolling an area that's known to have numerous blacktip sharks (Carcharhinus limbatus) — which can reach up to 8 feet. In the footage, two adult female orcas, including one called Quetzalli, split away from the rest of the pod to hunt a shark. However, it managed to escape to deeper water. 

On Jan. 21, 2022, local dive guide Carlos Lozano Hernandez spotted orcas attempting to kill a bull shark (Carcharhinus leucas) — a large, aggressive species that can grow to 11 feet (3.3 meters) long. The hunt was "a coordinated attack," according to the study.

"The shark could be seen on surface when one orca charged the shark on its side, missing the shark only to return to try again immediately, then turning upside down and attempting to hit the shark with her tail, a hunting technique known as 'lob-tailing' or 'tail-slapping'," the authors wrote in the study. 

Related: Florida shark attacks caused by heat, not scary orcas, experts say

A second orca chased the bull shark and charged it head on, then tried to smack it with her tail. The shark headed towards a boat, "splashing frantically and erratically," as it tried to put the vessel between it and its attackers, the researchers noted. The orcas circled their intended victim for 30 seconds before leaving the area. 

The last documented attack, which took place on Dec. 6, 2023, was fatal. Although the hunt itself wasn't captured on film, drone and underwater videos showed orcas with bull sharks in their mouths. Two of these orcas, named Niich and Waay, are in the same pod as Quetzalli. 

The phenomenon of orcas hunting sharks has been documented for over 50 years, according to the paper, although seeing it happen is rare. "Orcas have always naturally preyed on sharks and rays in the Gulf of California," said study author Jesús Erick Higuera-Rivas. "They hunt sharks because of the high nutritional content of sharks' liver and guts," he told Live Science in an email.

According to the study, sharks and rays "are likely underestimated in the diet of orcas." 

However, the recent increase in observations doesn't necessarily mean these hunts are happening more. It could be that modern technology, like drones and underwater cameras, is making it easier to spot and record the predation. 

If predation of sharks by orcas is increasing, it's too soon to say whether it could have an ecological impact, according to Higuera-Rivas. "So far we haven't collected enough scientific information," he said. 

In South Africa, two shark-eating orcas scared hundreds of great whites (Carcharodon carcharias) away from the Western Cape — but experts can't confirm if this might happen in the Gulf of California. "The population of the great white shark in South Africa is different from the population of other shark species that inhabit the Gulf of California," Higuera-Rivas said.

Rob Lott, policy and campaign coordinator at the wildlife charity Whale and Dolphin Conservation, who wasn't involved in the study, agrees. "It remains to be seen what the broader implications are for the ecosystem of orcas hunting sharks," he told Live Science via email. 

Apex predators like sharks play a key role in keeping the ecosystem in balance "so there will be consequences for new locations if the shark population relocates," he said. 

A rare, endangered baby dolphin has been spotted swimming with members of a different species in Cambodia, leaving scientists puzzled. 

The Irrawaddy dolphin (Orcaella brevirostris) calf was likely with its mother in a group of Indo-Pacific humpback dolphins (Sousa chinensis). Irrawaddy dolphins are dark gray with squished faces, while Indo-Pacific humpback dolphins are pink with long noses, so the calf and mother stuck out like saw thumbs. 

Researchers from Marine Conservation Cambodia (MCC) announced the sighting on May 31, posting on Facebook that the interaction was "extremely unusual" because the two species usually only come together when foraging in the same area. 

Becky Chambers, lead scientist at MCC's Cambodian Marine Mammal Conservation Project, told Live Science that her team was really excited to spot the calf, but they weren't sure why the two species were together.

"It is a bit of a mystery," Chambers said. "These are both highly threatened populations of dolphins and the fact that they're having interactions is, at the moment, I would say neither good nor bad."

Related: Dolphins are 'literally acting like jerks' by beating up baby manatees

Irrawaddy dolphins, known for spitting water out of their mouths and helping humans catch fish, are threatened with extinction partly because they get entangled in fishing gear. Researchers don't know how many Irrawaddy dolphins are left in the wild, but their population is severely fragmented, according to the IUCN Red List.

Chambers and her colleagues were conducting dolphin surveys off southern Cambodia on March 12 when they first encountered the young Irrawaddy dolphin calf. "We see juveniles quite often, but this was a newborn, which is an event in itself," she said.

Irrawaddy dolphins have been known to hybridize with Indo-Pacific humpback dolphins, but it's extremely rare, and this calf had all of the physical features of an Irrawaddy dolphin calf, according to the Facebook post. That means that it was likely born from two Irrawaddy dolphin parents.

Both species can engage in alloparenting — providing care to young that aren't direct offspring — which may, in rare instances, extend to other species. However, it's unclear whether the Indo-Pacific humpback dolphins were trying to help care for or harm the calf. 

Chambers noted that the Indo-Pacific dolphins may have attempted to separate mother from calf in an act of aggression, perhaps motivated by competition. "I'm on the fence about whether this was an aggressive interaction or not," she said. 

But it appears as though the calf survived its time with the Indo-Pacific humpback dolphins. On April 23, one of Chambers' colleagues likely spotted the calf again. This time, the researcher followed a lone Indo-Pacific humpback dolphin, which to their surprise, swam to a group of Irrawaddy dolphins. Why the Indo-Pacific humpback dolphin joined a group of Irrawaddy dolphins is also unclear, but that group of Irrawaddy dolphins had a young calf, and Chambers believes it was the same one that was spotted in the Indo-Pacific humpback dolphin group. 

"They didn't have a good camera, so no photo ID could be taken on that occasion, but it would be likely that is the same individual, which is good if it is because it means the calf is still alive," Chambers said.

Orcas that have been bumping boats in Iberian waters for four years are likely just bored teenagers with too much time on their flippers, experts say.

A report published May 24 found that orcas (Orcinus orcas) involved in a string of boat-ramming incidents in southwestern Europe are spending less time hunting and more time exploring new games now that populations of their favorite prey have rebounded. At least 673 interactions with boats since May 2020, six of which caused the boats to sink, may have resulted from these orcas having more free time, according to the report.

Something about the rudder on the underside of boats appears to attract orcas, particularly young members of the pod that are generally more curious. Whatever it may be, "as they play with the rudder, they don't understand that they can damage the rudder and that damaging the rudder will affect human beings," co-author Alex Zerbini, a senior research scientist at the University of Washington who chairs the scientific committee of the International Whaling Commission, a global body tasked with whale conservation, told The Washington Post. 

"There's nothing in the behavior of the animals that suggests that they're being aggressive," Zerbini said.

Fifteen orcas are known to interact with boats, most of them young and teenage males, according to the report. These orcas are a subset of the critically endangered Iberian population, which is thought to number fewer than 40 individuals.

Related: Infamous boat-sinking orcas spotted hundreds of miles from where they should be, baffling scientists

A video released May 17 by the Spanish group Conservation, Information and Research on Cetaceans (CIRCE) shows how the orcas break rudders by nudging them with their noses and heads. It remains unclear how the behavior started, but scientists have largely discarded previous suggestions it could be motivated by revenge and now believe it is more likely related to play. 

An orca may have initiated the behavior after touching the rudder of a boat and feeling it was fun to play with, Zerdini said.

"It's a very dangerous game they're playing, obviously," co-author Naomi Rose, a senior scientist and marine mammal expert at the Animal Welfare Institute in Washington D.C., told The Washington Post. "But it's a game." 

Iberian orcas playing with boats could be linked to a rise in the abundance of Atlantic bluefin tuna (Thunnus thynnus), their favorite food, according to the report. Bluefin tuna were previously the target of rampant overfishing, with numbers nosediving to critical levels in the late 1990s and early 2000s, but populations in the eastern Atlantic Ocean and Mediterranean Sea have largely bounced back over the past 15 years. 

The recovery of bluefin tuna stocks could mean orcas "have all this leisure time on their hands because they don't have to eat every fish they find," Rose said. Ramming boats may be trending in a similar way to previous fads — which include orcas wearing dead salmon as hats and tossing baby porpoises around — but there isn't enough data to determine exactly how the behavior is spreading within the population, according to the report.

Ramming boats may be a game to orcas, but it certainly isn't for mariners. In the report, scientists outlined measures to limit the "satisfaction or reward" orcas gain from interacting with boats. These measures include steering clear of orcas when possible, fitting boats with rudders that are abrasive or bumpy rather than smooth and making banging sounds in the water.

"We don't want to see more boats being sunk and we don't want to see people in distress," Zerbini said. "But we also don't want to see the animals being hurt. And we have to remember that this is their habitat and we're in the way."

Orcas that have been terrorizing boats in southwest Europe have just sank their fifth yacht in three years. And experts have warned that more attacks are likely in the coming months after the orcas unexpectedly switched up their behavior earlier this year.

On Sunday (May 12), an unknown number of orcas (Orcinus orca) attacked the 49-foot-long (15 meters) sailing yacht named the Alboran Cognac in the Strait of Gibraltar — a narrow body of water between southern Spain and North Africa that separates the Atlantic Ocean and Mediterranean Sea. During the attack, which began at around 9 a.m. local time, the killer whales repeatedly rammed the boat's hull and rudder, Reuters reported. 

The yacht's two-person crew radioed for help and was rescued by a passing oil tanker. But the vessel's hull sustained serious damage during the attack and the yacht began to take on water, which eventually caused it to sink, Reuters reported.

The attack was likely carried out by a growing number of individuals from the Iberian subpopulation of orcas — a group of around 40 killer whales that live off the coasts of Spain, Portugal, Morocco and Gibraltar — that have been attacking boats across their range since 2020. 

Most of the attacks occur between May and August each year in and around the Strait of Gibraltar. However, earlier this year, some of the highly social apex predators were spotted circling a boat in northern Spain, suggesting they have spread out much further and earlier than normal.

As a result, the Spanish authorities have warned recreational boaters to avoid sailing too far from the coast and to not stop their vessels if they are approached by orcas, according to a translated statement from Spain's Maritime Safety and Rescue Society.

Related: Orcas are learning terrifying new behaviors. Are they getting smarter?

Since the attacks started in 2020, sailors have reported around 700 interactions with orcas in the area, ranging from circling and nudging vessels to ramming, ripping apart and sinking boats, Reuters reported.

The most recent sinking event prior to this one occurred on Halloween last year when a pod of orcas sank a sailing yacht in the Strait of Gibraltar after a near hour-long attack. Before then, at least three other boats were sunk in the region between 2022 and early 2023. However, no humans have been injured or killed.

During attacks, the orcas' most common tactic is to damage or rip off the vessel's rudder, which makes it impossible to steer the vehicles. Researchers believe this is a learned behavior, and eye-witnesses have previously reported seeing individuals seemingly teach other orcas how to do this. As a result, the number of attacks has increased over the last few years.

So far, at least 15 individuals have been linked to at least one attack in the region. But researchers believe the attacks can be traced back to a single female, named White Gladis, who may have been pregnant when she started harassing the boats. However, it is unclear exactly what sparked the attacks.

There has even been a suggestion that the behavior has spread beyond the Iberian population after an orca similarly attacked a boat in Scotland in 2023. However, this was an isolated incident, which makes it hard to link it to the Iberian attacks.

Japan's commercial whaling activities could soon expand to include fin whales, government officials announced last week.

The move, which experts have heavily condemned, would increase the number of whale species Japan hunts in its territorial waters to four; the other three species are the Bryde's whale (Balaenoptera edeni), the sei whale (Balaenoptera borealis) and the minke whale (Balaenoptera acutorostrata). 

For now, it appears the decision to include fin whales hinges on public approval of changes to the country's marine resource management policy, according to the marine conservation organization OceanCare. 

The fin whale (Balaenoptera physalus) is the second-largest whale species on Earth, after the blue whale (Balaenoptera musculus). Fin whales are named for the distinctive fin that protrudes from their lower back, and they can grow up to 85 feet (26 meters) long. They are found across all the world's oceans. In the first half of the 20th century, however, fin whale populations nose-dived due to commercial whaling and they are still recovering from the shock, according to the International Whaling Commission (IWC), which regulates modern whaling practices.

In 1982, the IWC introduced a moratorium on commercial whaling that went into effect in 1986. Although Japan stopped commercial hunts after 1986, the country resumed taking whales for what it said was scientific research one year later. In 2019, Japan withdrew from the IWC and began catching whales commercially once again, although its whaling activities are now restricted to the country's territorial waters in the North Pacific Ocean.

Related: Hidden DNA found in blue whales reveals they've been mating with other species — and their hybrid offspring

On May 9, officials announced that Japan could start hunting fin whales soon. "Whales are important food resources and should be sustainably utilized, based on scientific evidence," Yoshimasa Hayashi, Japan's minister for foreign affairs, said at a news conference.

According to the IWC's most recently published whaling data, Japan took 25 sei whales, 187 Bryde's whales and 58 minke whales in 2022. In recent years, the country has also imported fin-whale meat from Iceland, according to OceanCare. 

The International Union for Conservation of Nature (IUCN) lists fin whales as vulnerable to extinction globally, although the species was still listed as endangered as recently as 2018 and is considered as such under the Endangered Species Act of 1973. However, there is insufficient data to pinpoint the status of local populations in the North Pacific, according to the IWC. 

Without reliable population estimates, Japan's move to hunt fin whales is an "appalling step backward" for ocean protection, Clare Perry, a senior adviser at the Environmental Investigation Agency (an international NGO that investigates environmental crime and abuse), said in a statement. 

"Fin whales are one of Earth's great carbon capturers and should be fully protected, not least so that they can continue to fulfill their critical role in the marine environment," Perry said.

The announcement comes after Japan unveiled a brand-new whaling "mother ship" in March. The factory ship, called the Kangei Maru, can handle and process large whales, including fin whales, "which could tie Japan into decades more of this destructive, unsustainable, inhumane and outdated industry," Perry said.

Whether or not Japan goes ahead with its plans to hunt fin whales depends on the outcome of a public consultation of the country's newly drafted whaling policy — but it seems likely the changes will be approved, according to OceanCare.