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?

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!

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?

Stunning images showing a deer carrying a rival's rotting head and a lynx playing with its food are among the shortlisted entries for an annual wildlife photography competition's people's choice award.

The Wildlife Photographer of the Year Nuveen People's Choice Award 2026 is hosted by the Natural History Museum in London. Anyone anywhere in the world can now vote for their favorite photograph online.

Other image highlights include a "superpod" of spinner dolphins (Stenella longirostris) driving their food to the ocean surface, and a tiger (Panthera tigris) with a rare genetic condition resulting in wide, dark stripes.

Two heartbreaking images of polar bears (Urus maritimus) are also among the shortlist: One photo shows a mother and her three cubs napping on the bare ground in Canada's summer heat, and the other captures a cub on a hunting trip in Svalbard that took a tragic turn when the cub and its mother roamed too close to a human settlement.

Voting closes March 18, and the winning photograph will be announced March 25. It will be displayed along with 100 images from last year's Wildlife Photographer of the Year competition in an exhibition at the Natural History Museum, London open until July 2026.

Wildlife Photographer of the Year is developed and produced by the Natural History Museum, London. Don't forget to let us know in the comments which image is your favorite.

Harpoons crafted from the bones of humpback and southern right whales show Indigenous groups in what is now Brazil were hunting whales 5,000 years ago.

The discovery, which included 118 whale bones and crafted artifacts, reveal that prehistoric whaling was not confined to people in temperate and polar climates in the Northern Hemisphere, according to a study published Jan. 9 in the journal Nature Communications.

"Whaling has always been enigmatic," because it's difficult to distinguish bone tools made from actively hunted and stranded animals in the archaeological record, study co-author André Carlo Colonese, a research director at the Autonomous University of Barcelona, told Live Science.

So the new tools are significant because their discovery alongside multiple bone remains from members of the same species represents some of the oldest evidence of active whale hunting in the world, the authors wrote in the study.

Prehistoric whaling

For prehistoric people, whales provided huge feasts, oil for warmth, and bones for tools and cultural ornaments and accessories. Although coastal communities have opportunistically salvaged these resources from beached whales for at least 20,000 years, the evidence of active hunting is much younger. For example, people hunted large whales with deer bone harpoons 6,000 years ago in what is now South Korea, and harpoons from around 3,500 to 2,500 years ago have been uncovered in the Arctic and sub-Arctic.

Colonese and his team did not originally set out to investigate early whaling. Instead, they were trying to document the marine species that were used by Indigenous Sambaqui populations in southern Brazil. To do so, they analyzed the molecular signature of precolonial cetacean (whale, dolphin and porpoise) bones at the Joinville Sambaqui Archaeological Museum in Brazil. Of the 118 bone remains with an identifiable cetacean species, most were from southern right whales, but many bones were from humpback whales. Only 37 had been crafted into items such as pendants.

It was "completely random" that one of the museum's curators brought out a box of what were believed to be sticks, Colonese said. But based on their design, such as hollow centers for a wooden shaft and carved tips, he immediately recognized them as harpoons. The team identified 15 harpoon elements, including heads and shaft components, made from either southern right whale or humpback whale rib bones.

The researchers took tiny samples from two harpoon foreshafts to determine their age, which revealed that the tools were between 4,710 and 4,970 years old. Colonese said he jumped for joy when he saw the results because these are some of the oldest harpoons found anywhere in the world — over 1,000 years older than the Arctic and sub-Arctic examples.

The discovery also showed that these Indigenous populations in Brazil were not simply gathering mollusks and catching fish. "The conventional idea was that the Sambaquis didn't have the technology" for whaling, Colonese said. "This is telling us that they were actually hunting."

"It's a very spectacular, informative discovery," Jean-Marc Pétillon, an archaeologist at the University of Toulouse in France who was not involved in the research, told Live Science.

Although it's not clear that these particular harpoons were used to hunt whales — as opposed to other marine animals, such as seals — this new evidence helps to contradict the assumption that whaling was practiced only in the Northern Hemisphere, according to Pétillon.

"Having these people living in southern Brazil in tropical conditions that also did whaling is also a way to change our perspective on these maritime exploitation systems," he said.

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?

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.

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?

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?

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

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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."

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.

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.

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.

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.

Orcas that have been terrorizing boats in southwest Europe since 2020 were recently spotted circling a vessel in Spain for the first time this year. The close encounter, which took place hundreds of miles from where the cetaceans should currently be, hints that this group is switching up its tactics — and scientists have no idea why.

The Iberian subpopulation of orcas (Orcinus orca) is a small group of around 40 individuals that lives off the coast of Spain and Portugal, as well as in the Strait of Gibraltar — a narrow body of water between southern Spain and North Africa that separates the Atlantic Ocean and Mediterranean Sea. 

Since 2020, individuals from this group have been approaching and occasionally attacking boats, sometimes causing serious damage to the vessels and even sinking them. The most recent sinking occurred on Oct. 31, 2023, but the orcas have sent at least three other boats to the bottom of the sea. However, no humans have been injured or killed.  

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

On April 10, three of these orcas were spotted persistently swimming near a large yacht off the coast of Malpica in Galicia, northern Spain, local news site Diario de Pontevedra reported. The trio did not attack the vessel, but local conservation group Orca Ibérica GTOA, which has been closely monitoring the Iberian subpopulation, warned boaters to "take caution when passing through" the area.

The encounter was surprising as the orcas don't normally venture this far north until mid to late summer, Spanish science news site gCiencia reported. 

"Theoretically, they are in the Strait [of Gibraltar] in the spring and should reach the north [of Spain] at the end of the summer," Alfredo López Fernandez, a biologist at the University of Aveiro in Portugal and representative of the Atlantic Orca Working Group, told gCiencia in the translated article. "There is an absolute lack of knowledge" about why this is happening, he added. 

Other orcas have also been spotted further east along the Spanish coastline toward Biscay and further south in Portuguese waters over the last few weeks, gCiencia reported. The orcas normally only enter these areas to follow tuna, their preferred prey. It is unclear if the tuna have arrived early this year.

So far, the orcas have not attacked any boats. But López Fernandez believes this could start within the next few months. However, he says it is hard to predict when and where these encounters will occur.

Scientists still don't know exactly why these attacks started. Some researchers believe that the first attacks may have been perpetrated by a lone female named "White Gladis," who may have been pregnant when she started harassing the boats. But regardless of how it started, the behavior quickly spread among the group. 

So far, at least 16 different individuals have attacked boats. Eyewitnesses also claim to have seen orcas teaching other individuals how to attack boats, with an emphasis on attacking vessels' rudders to immobilize them.

There is also a suggestion that the behavior may have spread outside the population after a boat in Scotland was attacked by a different group in June 2023. However, it is impossible to prove this attack was connected to the others.

As the number of attacks has increased, boat owners have started using firecrackers and even guns to scare off the orcas, gCiencia reported. However, scientists like López Fernandez have urged for restraint because the subpopulation is "in danger of extinction."

"We want to transmit real and truthful information," López Fernandez said. "We're not going to hide that the orcas can touch the boats and sometimes break something, but we also have to be aware that what we have in front of us is not a monster."

A young orca is refusing to return to the open ocean after its pregnant mother became stranded and died in a lagoon off Vancouver Island in Canada, rescuers say.

The mother and calf entered the lagoon, which extends south of the village of Zeballos on the island's northwest coast, on Saturday (March 23). The orca mom may have flipped onto her side while chasing a harbor seal (Phoca vitulina) and beached as the tide receded, Jared Towers, a marine scientist with Fisheries and Oceans Canada and director of the non-profit Bay Cetology, told CBC News.

Dozens of people tried to roll the stranded female onto her belly and provide her with water, but the orca didn't survive. A necropsy revealed she was pregnant when she died.

Since Saturday, rescuers have been trying to coax the orphaned calf back to sea, but the 2-year-old orca (Orcinus orca) has retreated further into the lagoon instead. Efforts are also hindered by the timing of the tides, with waters only rising high enough for the calf to safely navigate out of the lagoon during a 30-minute window each day.

Related: Dying orca's final moments after 'desperate' effort to stay afloat captured in 1st of its kind footage

"There's only half an hour every day that the whale can pass through that area as the tide goes slack, because other than that there's a lot of current, some rapids and for the most part very, very shallow water," Towers told The Canadian Press.

Members of the local Ehattesaht First Nation, who participated in the rescue effort, have named the young orca "Kʷiisaḥiʔis" (kwee-sa-hay-is), which translates to "Brave Little Hunter." 

"It is really important to remember that we are connected to these animals and I believe these events are really difficult but really important," Chief Simon John of the Ehattesaht First Nation said in a statement, according to The Canadian Press. "We have to take a bit of time to think what it means to us all. In our stories the killer whale came onto land and transformed into the wolf and then the wolf transformed into man." 

Rescuers have tried to guide the calf out to the ocean using acoustic orca calls and other methods, but to no avail. "We tried to move that little whale out over the shallows and back out into the inlet," Towers told The Canadian Press. "Unfortunately, the whale responded in a way that made us think it must be a bit traumatized."

The young orca appears to be otherwise healthy, Towers said. "It's got a great voice on it and it's using that voice, making a lot of loud calls," he said. "These killer whales can hear each other for many miles. It's just a matter of getting it out into the open water and letting it do the rest."

Rescuers hope the calf will find its pod again if it returns to the ocean.

Heartbreaking footage shows an orca mom and her adult son drowning a young calf from a neighboring pod. The dramatic video is likely the first time this rare behavior has been filmed. 

In the video, a female orca (Orcinus orca) and her daughters begin to play with the calf — a behavior that is not unusual when two pods come together. However, the play soon turns violent. The son hits the calf with force, then he and his mother trap the calf between them, forcing it underwater to drown it. 

The brutal clip was filmed as part of National Geographic's new series "Queens," which looks at the behaviors of matriarchs in the animal kingdom. 

Orca infanticide is extremely rare, and it wasn't something the production team was expecting to capture. "This behavior is so rare — in fact we think this is probably the first case of filmed orca infanticide," Chloe Sarosh, executive producer on the series, told Live Science. "We didn't plan to film it, it was just a case of right place, right time."

The team filmed the encounter over several hours, Sarosh said. A few days later, an orca that matched the size and description of the drowned calf washed up dead on a shore 5 miles (8 kilometers) away. It's assumed this was the same drowned calf.

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

Because the encounter was so unexpected, the team contacted several scientists to help interpret the behavior and confirm it was a case of infanticide. While the behavior of the matriarch and her son is clear, understanding the reactions of the other pod members and their roles will require further analysis. "That's why this footage is so important because it gives scientists a chance to study it to identify fins and markings of who and what role they're playing in this behavior," Sarosh said.

Infanticide among orcas is so rare it has only been documented once in published scientific literature, Charli Grimes, a researcher in animal behavior at the University of Exeter in the U.K., told Live Science in an email. "A lot of time is spent observing killer whales in the Pacific Northwest and given that it has only been documented once in the literature does appear to make it a rare event," she said.

The study, published in Scientific Reports in 2018, records a case of calf-killing among a population of transient killer whales in the North Pacific. Like the latest encounter, this involved an orca mother and her adult male son. Researchers captured footage of the aftermath of the 2018 event, but it doesn't show the moment the calf was killed. 

Scientists believe infanticide among orcas may enable the male to breed with the mother of the deceased calf. "The assumption is that this was done so that the mother would come back into estrus [a period of sexual receptivity] and the male would be able to mate with her and have more calfs in another pod to the matriarch — furthering the genes, furthering the genetic life," Sarosh said. 

"It's phenomenal behavior, really important behavior," she added. "It shows the power of the matriarch and the lengths that she'll go to, to do what is best for her pod and her son and her lineage."

If marine mammals want to sleep, they can't just close their eyes and drift away for the night, as they need to intermediately surface for air. Nor can they float at the water's surface and slumber, because that exposes them to predators and heat loss. So how do marine mammals get any shut-eye without putting themselves at risk?

One solution is to shut down one half of their brain at a time. Called unihemispheric sleep, it's one way marine mammals, such as dolphins, can get some rest while in open water.

"Unihemispheric sleep is really valuable to these animals because it allows them to maintain a low level of activity while still sleeping half of their brain at a time," Patrick Miller, a biologist at the University of St Andrews in the U.K., told Live Science.

Dolphins are the best-studied marine mammals capable of this style of sleeping. Brain scans on captive dolphins show that while one hemisphere is in slow-wave, deep sleep, the other hemisphere is alert, allowing the animals to literally sleep with one eye open. This style of sleeping is common in cetaceans — the group of mammals that includes dolphins, whales and porpoises — but it's not unique to them. Many bird species are known to use unihemispheric sleep, often allowing them to doze while flying.

But according to Miller, birds and dolphins use their half-brain sleeping technique for different purposes. For instance, in a flock of birds, many of the ones on the outside of the group keep the eye facing away from the flock open, to watch for predators. But dolphins do the opposite: While sleeping, they tend to keep the eye open that faces the rest of the pod, likely to avoid becoming separated.

Related: Why do horses sleep standing up?

Not all cetaceans seem to be capable of unihemispheric sleep. Some use bihemispheric sleep, in which both hemispheres of the brain fall asleep, just like humans and most other mammals do.

"It's really difficult to measure brain activities for animals out at sea that you're not able to capture, like a sperm whale, blue whale or a humpback whale," Miller said. "In that case, behavioral records are our best indicator of sleep behavior."

In those cases, researchers can affix tags to the animals to monitor their behavior. A 2008 study led by Miller used suction tags attached to sperm whales (Physeter macrocephalus) to show that they sleep out in the open ocean for short bouts. The whales make shallow dives beneath the surface, slow their swim speed to a stop, and pitch lazily upward. Their upward pitch is likely due to the buoyant oil, known as spermaceti, in their heads.

While sleeping, whole pods of whales can be seen nose-up, just below the ocean's surface. During this time, the animals are completely unresponsive, which suggests they are in a form of deep sleep. However, the animals can rest only about 20 minutes underwater before they need to come back up for air. Once the whale has caught its breath, it slinks below the surface for more rest, and may continue this behavior for up to 3.5 hours.

Northern elephant seals (Mirounga angustirostris) are bihemispheric sleepers as well and snooze in similar short bouts. A 2023 study led by Jessica Kendall-Bar, a postdoctoral researcher at the Scripps Institution of Oceanography, a department of the University of California, San Diego, was able to, for the first time, monitor brain activity in a sleeping mammal at sea. Kendall-Bar and colleagues found that the seals dive to a depth of around 1,000 feet (300 meters), at which point their brains slow down and enter rapid eye movement (REM) sleep. Once in REM sleep, the seals flip upside down and spin in a slow circle while continuing to sleep.

"Seals sleeping in the ocean were upside down 100% of REM sleep time, suggesting that just like us, they become paralyzed during REM," Kendall-Bar said in a YouTube video describing the research.

Likely due to predation risk, elephant seals limit their total sleep time at sea to just around two hours per day, "rivaling the record for the least sleep among all mammals, which is currently held by the African elephant (about 2 hours per day)," the researchers wrote in the study.

Beachgoers in South Carolina recently stumbled upon an eerie, skeleton-like dolphin sprawled across the sand, where it may have been slowly drying out for months. One expert suggests that the animal may have accidentally become stranded after deliberately beaching itself.

On Jan. 14, the Lowcountry Marine Mammal Network (LMMN) received a call about a "mummified dolphin" near Hilton Head Island, the organization's representatives wrote in a Facebook post. LMMN volunteer Amber Kuehn, a marine biologist and coordinator of the Hilton Head Island Sea Turtle Patrol, visited the site to measure and collect skin and teeth samples from the body, before burying the remains on the beach. 

The dolphin was most likely a common bottlenose dolphin (Tursiops truncatus) and was around 8 feet (2.4 meters) long, Kuehn told Live Science in an email. It was unclear how old or what sex the dolphin was, she added.  

"It wasn't actually mummified," Kuehn said. "It was simply decomposed." However, the level of decomposition was unusually high, she added. 

Kuehn believes the carcass could be several weeks old. However, Erich Hoyt, a research fellow at Whale and Dolphin Conservation (WDC) in the U.K. and author of several books on cetaceans, told Live Science that the remains could be months old. 

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

The corpse appears to have completely dried out due to its dry surroundings and being continually exposed to the sun, Hoyt said. But it is strange that the body desiccated to this extent while remaining fully intact, he added. 

Normally, remains like these would be picked clean by scavengers. For example, the day before this corpse was found (Jan. 13), LMMN volunteers were called to another bottlenose dolphin body near Botany Bay on Edisto Island. This corpse appeared to be similarly decomposed, but it had already been heavily scavenged. 

The mummified dolphin may have dried out somewhere else before washing up at Hilton Head Island, LMMN representatives wrote. But this is hard to prove. 

However, an interesting bottlenose dolphin behavior could explain how the two dolphins ended up on their respective beaches.

Small groups of bottlenose dolphins in South Carolina have previously been seen collectively surging onto the shore to drag small fish onto land in their wake, enabling them to pick off the helpless prey before rolling back into the water, Hoyt said. But if an individual lunges too far, it is possible they could become stranded and die before eventually desiccating, he added. 

But this is just one theory, and there is "no evidence of this having happened" in these recent cases, Hoyt said.

Dolphins are mysteriously attacking manatee calves — and this hostile behavior may be a regular occurrence, scientists say.

In a study published Jan. 10 in the journal PLOS One, researchers documented 10 aggressive interactions by bottlenose dolphins (Tursiops truncatus) towards Antillean manatee calves (Trichechus manatus manatus), which targeted orphans as well as youngsters that were with their mothers. The attacks occurred near Belize over a 21-year timespan, from 1999 to 2020, with the majority of instances occurring between 2015 and 2020.

"Dolphins do not eat manatees and why they act this way with another species is unclear," said study lead author Eric Angel Ramos, a scientist at the International Foundation for Nature and Sustainability (FINS), a team of international conservation scientists. "It's likely that they are quite curious when they encounter manatees, and because dolphins are often aggressive with each other, they display this behavior to other species like manatees," he told Live Science in an email.

The researchers observed dolphins attempting to separate calves from their mothers and harassing, ramming and biting them. In each case, the dolphins initiated the interaction.

Researchers believe the attacks were intentional. "I'm confident in saying that, yeah, I think they want to inflict death," study senior author Jeremy Kiszka, a biological science professor at Florida International University, told Live Science.

The researchers also found tooth rake marks — with spacing that indicated dolphin teeth — on orphaned calves during health checks at a rehabilitation center, providing further evidence of these violent assaults. 

Although scientists don't fully understand what's going on, dolphins are known to display similar behaviors with their own young and calves from other species. They have previously been recorded biting other dolphins, and are known to attack and kill harbor porpoises (Phocoena phocoena).

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

"Around the world we see bottlenose dolphins literally acting like jerks and being violent with other species," Kiszka said.

Dolphins might act aggressively towards manatees and other marine animals because they perceive them as competitors for food, space or resources, Kiszka said. And if these animals' ecosystems degrade due to climate change and human activities, there's a chance it could cause the species' habitats to overlap further, resulting in an increase in these hostilities, Kiszka said.

Bottlenose dolphins are an intelligent species. They have large brains, a wide range of complex emotions, including grief, and their own cultures.

The aggressive interactions between manatees and dolphins took place over many years, so they're likely more common than scientists previously thought and could impact the survival of the species. Antillean manatees are threatened across their range — this subspecies of the West Indian manitee can be found in marine, brackish and freshwater from southeastern Texas to northeastern Brazil. Even around Belize, which has a relatively healthy population, they are threatened by vessel collisions.

Understanding exactly what's going on could help conservationists protect calves and the wider manatee population, Kiszka said. "Any additional source of mortality is something we should be concerned about."

Animals can often be unpredictable and surprise us with their unusual behavior, but some newsworthy critters take this even further, leaving scientists and the public completely baffled.

While the weird behaviors on this list are a testament to the complex brains of our furry, finned and fork-tongued friends, there's also a darker side to some of these acts. Humans continued to disrupt and destroy the natural world in 2023, putting many animals under pressure and causing some to act in weird ways. Here are 10 of the strangest animal behaviors documented in 2023.

Kangaroo tries to drown dog

In October, a man captured a video of a kangaroo as it tried to drown his dog. Mick Moloney had to rescue his dog Hutchy from the Murray River in Victoria, Australia, after a male eastern gray kangaroo (Macropus giganteus) held Hutchy's head underwater. Moloney got Hutchy to safety but took a punch from the kangaroo for his efforts.

This isn't the first time kangaroos have behaved this way around our canine companions, and the marsupial was probably just looking out for its own safety. Kangaroos have learned to hop into water to defend themselves against attacks from canines.

Crocodile has "virgin birth"

Researchers announced the first crocodile "virgin birth" in June. A female American crocodile  (Crocodylus acutus) laid a clutch of eggs at a reptile park in Costa Rica after being alone for 16 years. This form of asexual reproduction had never been documented in crocodiles before, although it's known to occur in lizards, snakes, birds and sharks.

The crocodile's clutch didn't hatch, but genetic analysis of a fetus within one of the eggs revealed it was almost identical to the mother. The study's authors noted that offspring born in this way often suffer abnormalities and don't survive.

Dolphins raid crab pots

Bottlenose dolphins were spotted stealing bait from fishers in western Australia. The dolphins used their noses and teeth to pilfer fish from nets meant for crabs. Wildlife conservationists filmed this behavior for the first time in 2023, revealing the different ways dolphins learned to open the fishers' pots.

"The most basic version is that the dolphin grabs the bait which sits on a hook or metal pin inside the crab pot," filmmaker Axel Grossmann told Live Science in November. "So essentially the dolphins pull the fish off the pin or break it down into edible pieces."

When fishers tried putting bait underneath the pots, the dolphins learned to flip them over, and when they tried using bait boxes, the dolphins learned to open them. Eventually, fishers and conservationists developed a dolphin-proof design.

Elephant peels banana

A zoo elephant taught herself to peel bananas by watching zookeepers. Pha, a female Asian elephant (Elephas maximus) at the Berlin Zoo in Germany, rips off the stem of a banana, pinches the frayed skin with her trunk and uses the fruit's weight to peel. It's an ingenious twist on the human method, which normally involves two hands and opposable thumbs.

Keepers at the zoo used to feed Pha peeled bananas when she was a calf, which is probably where she got the idea. Pha only peels ripe bananas with brown spots. She eats green and yellow bananas whole and rejects brown bananas. When fed in a group where her bananas might get stolen by other hungry elephants, she peels only her last banana, presumably to savor it.

Crocodiles save dog

Three mugger crocodiles (Crocodylus palustris) seemingly helped a young dog that had been chased into a river by a pack of feral dogs by nudging it to safety. The researchers who witnessed the event interpreted the crocodiles' actions as empathy. They also reported that the species appears to use sticks as bait to catch nesting birds and is attracted to flowers. However, an independent expert was skeptical of their findings.

"Crocodilians do have a sophisticated suite of behaviors," said Duncan Leitch, a biologist who specializes in the neurophysiology of reptiles at the University of California, Los Angeles, told Live Science in September. "But some of these conclusions are using a human definition of intelligence and trying to find that in crocodilians."

Whale kelping goes global

Researchers first documented humpback whales (Megaptera novaeangliae) playing with seaweed in 2007, but the behavior, known as "kelping," is now so widespread, it's become a global phenomenon. Seaweed potentially acts as a body scrub for the whales, and they may use it to remove parasites, treat their skin or just play with it.

"It's something they do together as a social event or by themselves," Olaf Meynecke, a researcher at Griffith University's Coastal and Marine Research Centre in Queensland, Australia, told Live Science in September. "They put the seaweed on their head and roll around in it; they try to move it around with their pectoral fins as well."

Orca eats seven sea otters whole

In September, scientists described a beached orca (Orcinus orca) with seven intact sea otters in her belly. Orcas don't normally eat sea otters (Enhydra lutris) and typically chew the marine mammals they do eat, so researchers were puzzled why this orca gobbled down the sea otters whole.

To make matters even stranger, this killer whale was found on the coast of one of the Commander Islands in the Russian Far East, far from the orcas' normal range between the Gulf of Alaska and the coast of California. One of the sea otters was stuck between the orca's oral cavity and esophagus, which could have been the reason for the orca's demise.

Ants detect cancer in urine

In January, researchers discovered that ants can sniff out cancer using their antennae. Silky ants (Formica fusca) normally use the olfactory receptors in their antennae to find food or mates, but the researchers trained them to find tumors instead.

Once the ants learned to associate the urine of tumor-bearing rodents with sugar, the researchers found that the ants spent 20% more time next to urine samples from cancerous rodents than next to urine samples from healthy rodents. The ants could serve as cheap and efficient cancer detectors in the future, though much more science needs to be done first, the researchers said. Dogs can also learn to sniff out cancer, but researchers found that ants are easier to train.

Mice kill largest flying birds

Invading mice killed eight wandering albatrosses (Diomedea exulans) — the world's largest flying birds — on a remote island between South Africa and Antarctica. The mice have been eating native seabird chicks on Marion Island for decades, but taking down adults is a new phenomenon — and it's worrying conservationists.

Humans inadvertently introduced house mice (Mus musculus) to the island in the 19th century after the rodents hitched a ride on ships. The island's native wildlife isn't equipped to defend itself against rodents because it didn't evolve alongside the mice. The Mouse-Free Marion project will try to use rodenticide to kill off the mice before they can do any further harm to wandering albatrosses and other threatened species that call the island home.

Orcas sink two boats

Orcas in the Strait of Gibraltar sank two boats in 2023 and attacked a number of others with ruthless efficiency. Why orcas have started attacking boats is an open question, but the behavior may stem from a traumatic experience, play, frustration or a temporary fad within the population. 

In the 1980s, an orca population in the Pacific went through a phase of carrying dead salmon on their heads for no obvious reason, so it's possible for orcas to pick up temporary behaviors and teach them to each other. The coordinated boat attacks are just one example of how orcas show their terrifying intelligence.

This year was all about White Gladis, the orca that became a global sensation because of her apparent hatred for boats. The orcas began ramming boats in 2020, but it wasn't clear what had kicked off this weird behavior — researchers were understandably hesitant to unpick the thoughts of a pod of killer whales.

But in May, scientists identified White Gladis as the ringleader and finally explained her motivations. Experts said a traumatic experience with a boat had flipped a switch. She started attacking boats. Others then copied her behavior and the boat-sinking saga began.

Seeing a real-time shift among a population of super-smart predators has been fascinating — and understanding that the boats and their human owners started it should make us think a little more about how we interact with our environment. The orcas were in the oceans first.

Scientists don't know what'll happen next. They're social animals and terrifying behaviors can spread among pods. Or they may just get bored of the boats and stop. We'll learn more next year.

Orcas have sunk 3 boats in Europe and appear to be teaching others to do the same. But why?

Imagine diamonds exploding from Earth in huge volcanic eruptions akin to Mount Vesuvius. That's what scientists think happened when the supercontinent Pangaea broke up — the centers of these mammoth landmasses become so stretched and thin, diamonds that have been patiently sitting beneath them come shooting up from Earth's core in a big old sparkly explosion. And Live Science will take a deeper look at what these sparkly gems can reveal about the birth and death of supercontinents in 2024, so stay tuned.

Fountains of diamonds erupt from Earth's center as supercontinents break up

A dolphin with thumbs was spotted playing in the Gulf of Corinth. What a wonderful world we live in.

See photos of the extremely rare dolphin with thumbs

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A strange dolphin in the Gulf of Corinth has developed intriguing, hook-shaped "thumbs" carved out of its flippers, photographs show.

Researchers with the Pelagos Cetacean Research Institute spotted the dolphin on two occasions this summer during boat surveys off the coast of Greece. Despite the unusual appearance of its flippers, the animal kept pace with the rest of its pod and was seen "swimming, leaping, bow-riding, playing" with other dolphins, said Alexandros Frantzis, the scientific coordinator and president of the Pelagos Cetacean Research Institute.

"It was the very first time we saw this surprising flipper morphology in 30 years of surveys in the open sea and also in studies while monitoring all the stranded dolphins along the coasts of Greece for 30 years," Frantzis, who took the pictures of the thumbed dolphin, told Live Science in an email.

The Gulf of Corinth is a semi-enclosed pocket of the Ionian Sea, sandwiched between the Greek mainland and the Peloponnese peninsula. It is home to a unique mixed-species society of dolphins that includes common dolphins (Delphinus delphis), Risso's dolphins (Grampus griseus) and striped dolphins (Stenella coeruleoalba). The thumbed specimen was a striped dolphin, Frantzis said.

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

Around 1,300 striped dolphins live in the Gulf of Corinth, where they are isolated from the rest of the Mediterranean population. The unusual flipper "does not look like illness at all," Frantzis said. Instead, it may be "the expression of some rare and 'irregular' genes" that cropped up due to constant interbreeding, he said.

Lisa Noelle Cooper, an associate professor of mammalian anatomy and neurobiology at the Northeast Ohio Medical University, agreed that the dolphin's defect is likely rooted in its genes. "I've never seen a flipper of a cetacean that had this shape," Cooper told Live Science in an email. "Given that the defect is in both the left and right flippers, it is probably the result of an altered genetic program that sculpts the flipper during development as a calf." 

Cetaceans — a group of marine mammals that includes whales, dolphins and porpoises — have evolved distinct forelimbs with more phalanges, or finger bones, compared with other mammals. These bones are arranged into human-like "hands" encased in a soft-tissue flipper, said Bruna Farina, a doctoral student specializing in paleobiology and macroevolution at the University of Fribourg in Switzerland.

This means dolphins have thumbs, although they aren't as prominent as ours and are concealed by their flippers, Farina told Live Science in an email.

Unlike in humans, whose fingers are fused into paddle-shaped hands in the womb with cells that die off before we are born, cells accumulate around dolphins' forelimb bones to form flippers, Cooper said. "Normally, dolphins develop their fingers within the flipper and no cells between the fingers die off," she said.

But the dolphin photographed in the Gulf of Corinth appears to be missing fingers and some of the tissue that would usually encase them. "It looks to me like the cells that normally would have formed the equivalent of our index and middle fingers died off in a strange event when the flipper was forming while the calf was still in the womb," Cooper said.

The dolphin's thumb and fourth digit, however, remained. "The hook-shaped 'thumb' may have some bone inside of it, but it certainly isn't mobile," Cooper said, adding that "no cetaceans have mobile thumbs." 

"It is lovely to see that this animal is thriving," Cooper added.

The final moments of an adult orca's life have been recorded in what is believed to be the first footage of its kind.

Whale-watchers spotted an orca (Orcinus orca) — a roughly 35-year-old male known to researchers as Hunchy after his hunched back — behaving strangely in waters north of the island of Loppa in Norway on Nov. 6. Two younger orcas huddled close to Hunchy, seemingly holding him at the surface so he could breathe, Pierre Robert de Latour, the author of "Frère des Orques" (Glénat, 2019) who has been diving with orcas in Norway for over 20 years and was on the whale-watching expedition, told Live Science.

The attempt to keep Hunchy afloat seemed "desperate," Robert de Latour said, adding that "it was obvious that he was in trouble."

Robert de Latour got into the water and snorkeled up to the orcas to take a closer look. He noticed the old male looked skinny, and the shape of his belly suggested he hadn't eaten for a long time.

The footage shows Hunchy floating motionless just below the ocean surface after the two younger orcas left the scene. The young pair swam back and forth between Hunchy and a group of orcas further away, Robert de Latour said, repeatedly trying to "activate" the old male.

Related: Orcas sink another boat in Europe after a nearly hour-long attack 

"It's the first time for me seeing something like this. I recognized him — it was very emotional — and then I saw his giant body sinking," Robert de Latour said. "It is said that orcas don't abandon individuals that are in trouble."

The young orcas realized that if they left Hunchy, he would sink to his death, he added. (Orcas can stay submerged for up to 15 minutes, but they usually come to the surface to breathe every minute when resting, and every three to five minutes when traveling.)

But after 50 minutes, they seemingly gave up. "They were helping him until the very last moment," Robert de Latour said.

The footage could be the first time the death of an adult orca has been filmed in the North Atlantic — and possibly worldwide, said Filipa Samarra, a research specialist at the University of Iceland and the founder and principal investigator of the Icelandic Orca Project.

"To my knowledge, the death of an adult member of the group, and how the other [orcas] behave in that instance when an adult is dying, is something that has not been observed before," Samarra told Live Science in an email.

However, researchers have previously recorded the moments surrounding the death of a calf. "We know that orcas show very specific behaviors when calves die," Samarra said. "They have been observed numerous times carrying them, pushing them to the surface, and this can go on for many days." One incident involving orcas from the southern resident population saw a mother carrying her dead calf for over two weeks, she said.

Whether these really were Hunchy's last moments remains to be confirmed. A second boat that arrived on the scene reportedly witnessed the same struggle unfolding one or two hours later, Robert de Latour said, but the crew couldn't determine if Hunchy managed to swim back up to the surface alone or if the younger orcas hauled him up one last time.

"He's probably dead now," Robert de Latour said.

Editor's note: This article previously said the southern resident population saw a mother carrying her dead calf for over two years. It should have said two weeks. This was corrected on Thursday, November 30.

Dolphins have learned how to outsmart crab fishers by stealing the bait from their pots — and new footage has captured the unique behavior for the first time.

The bottlenose dolphins watch as the crab fishers load their nets with fish and drop them into the ocean off Koombana Bay, Western Australia. Then, the animals nose their way into the nets and pull the bait off the hooks in the crab pots.

The crab fishers tried putting the bait underneath the pots or in bait boxes to deter the thieves, but the dolphins quickly learned how to tip them over or open the boxes.

Wildlife conservationist Rodney Peterson first spotted the behavior two years ago and was concerned that the dolphins would become tangled in the nets or eat unhealthy food.

He approached the Dolphin Discovery Centre in the city of Bunbury, which set up five cameras to film the animals in action.

Related: 11 ways orcas show their terrifying intelligence

"Dolphins are very smart, brilliant observers and forage for food all the time. Often, when they see an opportunity they will go for it, especially the mothers with calves," filmmaker Axel Grossmann, who volunteers at the Dolphin Discovery Centre alongside wildlife conservationists, told Live Science in an email.

The dolphins opened the pots in different ways. "The most basic version is that the dolphin grabs the bait which sits on a hook or metal pin inside the crab pot. So essentially the dolphins pull the fish off the pin or break it down into edible pieces," Grossmann said.

To deter the mammals, some of the fishers placed the bait underneath the crab pots, which meant the dolphins had to use more sophisticated techniques to get it. "They learned to turn crab pots around using their rostrum (jaws) and bodies, so they could access the bait more easily," Grossmann said.

The dolphins even opened bait boxes — plastic containers used to hold the bait. "Some locksmith dolphins have learned to open the latch with their rostrum or teeth — and once the lid of the box opens, they grab the fish," Grossmann said.

Because the conservationists worried that the dolphins would become entangled or injured, they developed a new, dolphin-safe solution.

"We and some crab fishermen developed a mesh bait pouch with a metal hook that kept the bait closed in tight," Grossmann said. "The dolphins learned that it wasn't accessible, so they swam off. It means we get healthier dolphins and happier crab fishermen."

Dolphins steal food for different reasons, Grossmann said.

"If they are hungry, they might put more effort into working out how to forage for additional food sources like crab bait, especially in an area that is highly frequented by humans. Essentially the dolphin sees humans putting food on a plate in their backyard," he said.

But not all dolphins are doing it, so there may be other reasons why the animals are going after the crab bait.

"We believe it is a mixture of interest, an easy way to get a fish, learned adaptive behavior and maybe even a bit of fun," Grossmann said.

A pod of orcas has attacked and sunk another boat in southwestern Europe after relentlessly bombarding the vessel and its crew for almost an hour on Halloween. It is the fourth time that orcas from this region's population have sunk a vessel in the last two years.

On Oct. 31, the Grazie Mamma — a mid-size sailing yacht owned by Polish cruise company Morskie Mile — was attacked by an unknown number of orcas for around 45 minutes off the coast of Morocco in the Strait of Gibraltar, Morskie Mile representatives wrote in a Facebook post translated from Polish.

The orcas (Orcinus orca), also known as killer whales, repeatedly hit the yacht's rudder causing major damage and allowing water into the vessel's hull. Despite receiving aid from the Moroccan Navy and being towed toward safety, the boat eventually sank as it entered the port of Tanger-Med in Morocco. All passengers were safely evacuated to rescue boats before the ship sank.

The unusual attack is the latest example of one of many unnerving new orca behaviors that have highlighted the striking intelligence of these deadly predators. 

Related: 11 ways orcas show their terrifying intelligence 

Since 2020, orcas have been regularly harassing boats in the Strait of Gibraltar — a narrow strait between Spain and Morocco that connects the Atlantic Ocean to the Mediterranean Sea — and the surrounding waters off the coast of the Iberian peninsula. 

These nautical raids were likely started by a pod including White Gladis, a female orca who may have been traumatized by a past boat collision. The unusual behavior then spread among other individuals who seem to be becoming more daring and efficient with their attacks.

So far, at least three other boats have been sunk in the area, with the most recent incident occurring in May 2023 and the previous two both occurring in 2022. And in June, a yacht had its rudder ripped clean off with "ruthless efficiency" in a 15-minute attack. 

Researchers suspect that orcas are learning to attack boats from one another. Witnesses have also reported seeing orcas "teach" other individuals how to maximize the damage they cause, Live Science previously reported.

Related: How often do orcas attack humans?

So far, only one other boat has been attacked outside of the Strait of Gibraltar and its surrounding waters: A yacht in Scotland, more than 2,000 miles (3,200 kilometers) away, which was rammed by a lone individual. However, it is impossible to directly link this attack to the other orcas. 

Boat attacks are not the only unusual learned orca behavior that scientists have taken note of in recent years. 

Since 2017, a pair of orcas known as Port and Starboard have killed dozens of great white sharks in South Africa by ripping out their livers. And on Oct. 17 this year, this behavior was also documented in Australia for the first time, hinting it may also be spreading.  

Rare footage has captured an enormous megapod of dolphins joining together to hunt flying fish in the Pacific Ocean off Costa Rica. The video shows one of the biggest groups of spinner dolphins ever filmed, with thousands banding together in a gathering that extended deep underwater.

The event was captured as part of PBS's "Spy in the Ocean, a Nature Miniseries," in which the team uses spy cameras attached to animatronic animals to infiltrate wild groups. Off Costa Rica, a "spy dolphin" was deployed among a group of spinner dolphins (Stenella longirostris) — a species known for its acrobatic, twisting leaps out of the water.

The megapod sequence was very hard to capture, Matthew Gordon, a wildlife producer on the show, told Live Science via email. "It was extremely difficult to even find the spinner dolphins, so there were many days out at sea where we traveled hundreds of kilometers over the duration of the shoot and couldn’t even find them. But when we did find them, that’s when the magic happened," he said.

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

Once they had found the pod, the team placed the spy dolphin in the mix and used an animatronic bird drone to observe the dolphins from the sky.

The clip shows the dolphins communicating with one another through clicks and whistles. They appear to gather other dolphins from more distant areas of the ocean by signaling their presence with leaps.

Gordon said the pod eventually covered an area of around 108,000 square feet (10,000 square meters) at the surface. "But that was just the tip of the iceberg, as when you looked underwater, the pod also continued down as far as the eye could see — and that was in reasonably clear water," he said, adding the pod contained a few thousand dolphins at its peak.

"Spy in the Ocean" uses lookalike robots in the hopes of capturing realistic behavior; otherwise, the animals might be distracted by large, obtrusive cameras. "With Spy Dolphin being in the heart of the action, it gave us a unique perspective in what it would be like to be another dolphin among the real tuna and dolphins," Gordon said.

Orcas are one of the most successful species in the seas, reigning at the top of the food chain in every ocean. And one of the reasons they are so successful is simple: they're really, really clever.

Orcas (Orcinus orca) have rich and distinct social lives and have learned a remarkable variety of hunting strategies to take down everything from blue whales to great white sharks. Here are 10 examples of orca intelligence that prove killer whales are killer smart.

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

They get caught up in fads

Orcas are social learners and occasionally get caught up in fads — a temporary behavior started by one or two individuals, adopted by others and then swiftly abandoned. For example, a population in the Pacific went through a phase of wearing salmon as hats in the 1980s. The trend started when a female orca began carrying around dead salmon on her head, and in the weeks that followed, the behavior spread to two other pods in the same community.

Researchers spotted the salmon-wearing orcas doing the same behavior the following year and then never saw them carry fish on their heads again, according to a 2004 review of nonhuman culture published in the journal Biological Conservation. Recent orca attacks on boats in Europe may be another example of a killer whale fad.

Related: Orcas attack boat with ruthless efficiency, tearing off rudders in just 15 minutes

They engage in "greeting ceremonies"

Killer whales have complicated social rituals and even engage in what researchers call "greeting ceremonies." These interactions are the orca equivalent of a mosh pit, with orcas lining up in two rows and then tumbling together, Smithsonian Magazine reported. During one such event, the greeting coincided with a birth. Three orca pods reunited in the Strait of Juan de Fuca on the boundary between the U.S. and Canada in 2020, and as the orcas whistled and clicked to each other, a pregnant female produced a calf, KUOW, Seattle's National Public Radio news station, reported. The orcas weren't foraging and appeared to be there just to socialize on the day of the birth.

They have distinct dialects

Orcas live in pods based around related mothers and their descendants. Each pod has its own distinctive calls, like different dialects of the same language. The species can learn to mimic new sounds, which may help them form these dialects.

Researchers taught a captive female orca called Wikie to mimic human words like "hello" and "bye-bye," as well as the calls of some other animals. Wikie learned quickly and could reproduce some new sounds on her first attempt.

They employ specialized hunting strategies

Orcas learn highly specialized hunting strategies and pass that knowledge to their offspring. Some killer whales in Argentina beach themselves to snatch seals on the shore, while in Antarctica, other populations create waves to push seals off floating sea ice.

And it's not just seals they learn unique strategies for; killer whales are salmon specialists in parts of the Pacific, beaked whale hunters off Australia and sting-ray snatchers off New Zealand, according to the International Union for Conservation of Nature's (IUCN) Red List.

Related: 'Chaos of clicks and sounds from below' as 70 orcas kill blue whale

They're picky eaters

Some orca populations seem to have learned that shark livers are particularly rich in nutrients and that it's worth killing sharks and discarding the rest of their carcasses just to get to the nutritious organs. Researchers have documented killer whale populations targeting the livers of a variety of sharks, including attacking great white sharks (Carcharodon carcharias) off South Africa and tearing open whale sharks (Rhincodon typus) off Mexico.

They appear to have friends

A 2021 study published in the journal Proceedings of the Royal Society B found that orca social bonds are comparable to those seen in primates, including humans. A killer whale interacts more with certain members of its pod, usually those of a similar age and of the same sex.

Michael Weiss, research director of the Center for Whale Research in Washington state, led the study and spoke to Science about two distantly related young males that were always together during the research. "Every time you see a group of whales, those two are right there interacting with each other," Weiss said. "I wouldn't hesitate to use the word friendship here."

They seem to grieve

In 2018, researchers spotted a seemingly grief-stricken female orca pushing her dead newborn calf around. The orca, named Tahlequah, pushed her lifeless calf for at least 17 days, covering 1,000 miles (1,600 kilometers) of ocean before she eventually let go of it. The Center for Whale Research described it as a "tour of grief."

Wildlife charity Whale and Dolphin Conservation noted on its website that researchers have documented several species of whales and dolphins carrying deceased calves or juveniles, and these "mourning behaviors" are likely common among social, long-lived mammals. Scientists have historically been reluctant to use words like "grief" for fear of projecting human emotions onto animals, BBC Earth previously reported. The motivations behind this behavior still aren't fully understood.

They can be trained

Humans have been training captive orcas for decades. At SeaWorld, for example, killer whales strike poses, splash crowds, wave their pectoral fins and generally flip-flop around on command.

Keeping killer whales in an artificial environment is controversial, with some experts arguing that it causes stress and contributes to disease. SeaWorld announced it was ending its orca captive breeding program in 2016, and the orcas it has now will be the last generation in its care.

They care for one another

Researchers have documented numerous examples of orcas supporting their fellow pod members. For example, orcas have helped injured or deformed family members survive by catching food for them, the Daily Mail previously reported. Killer whale mothers also care for their sons well into adulthood, and orca grandmothers care for their grandchildren after they go through menopause (one of a handful of species to do so).

A 2015 study published in the journal Current Biology found that older females also guide their pod members to food, especially during tough times when food is scarce, suggesting that orcas that no longer reproduce support the survival chances of the pod by imparting wisdom.

Their brains are big

A killer whale's brain can weigh as much as 15 pounds (6.8 kilograms) and is well equipped for analyzing underwater environments, the Orlando Sentinel reported in 2010. One of the species' most impressive intellectual tools involves echolocation. Orcas click to create sound waves and locate prey by detecting when those waves bounce off something. Researchers believe that southern resident killer whales, an orca population that lives off the Pacific Northwest coast, can distinguish chinook salmon from other fish by detecting the size and orientation of salmon swim bladders, which give off unique acoustic signatures, according to the National Oceanic and Atmospheric Administration.

They hunted whales with humans

 For around 1,000 years, a population of orcas off the coast of Australia hunted alongside Indigenous people, and later European whalers. They would hit the water to alert humans to the whales' presence and would sometimes tow them to their location using a rope. In exchange, the humans gave the orcas the whales' lips and tongues. The relationship became known as the "Law of the Tongue." It continued until the 1930s, by which time commercial whaling had caused baleen whale stocks to plummet. The orcas left, and this killer whale population is now believed to be dead.

A mysterious population of orcas said to have hunted alongside Indigenous Australian whalers for millennia and European whalers for decades appears to be extinct, genetic analysis has revealed.

The coastal Thaua people, part of the Yuin nation, would sing to the beowas (orcas) as they hunted baleen whales together for generations in the bay of Turembulerrer (Twofold) off eastern Australia. Orcas took only the lips and tongue of slain whales in a mutually beneficial exchange called the "Law of the Tongue," according to a study published Oct. 12 in the Journal of Heredity.

In the 19th Century, European colonizers took advantage of this law to create a booming commercial whaling operation in the bay. Written records suggest orcas would slap the waters in front of the whaling station in the town of Eden to alert the whaling teams, which included Thaua people, to the presence of whales. The orcas are said to have led the whalers to the whales, sometimes by towing them on a rope, and manipulated the harpoon line to slow a snagged whale down and help secure the kill.

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

By the 1930s, after hunting with humans for 1,000 years, the population vanished.

To learn more about these orcas, researchers analyzed the DNA of a 23-foot-long (7-meter) orca (Orcinus orca) from this group called "Old Tom." His DNA proved different enough to living orcas to suggest that the whale-hunting population he belonged to is now extinct.

The study also tapped into traditional knowledge to learn more about the relationship between Indigenous Australians and the "killers of Eden." Study coauthor Steven Holmes, a Thaua Traditional Custodian, wrote in the study that the Thaua people consider beowas (orcas) to be their brothers, connected through Dreamtime stories that say when a Thaua member dies, they are reincarnated as a beowa.

"My people had a long-lasting friendship with the beowa in Eden, especially Old Tom," Holmes said. "My Nan, Catherine Holmes nee Brierly, told us about her great Grandfather, Budginbro who along with other Thaua would swim with Old Tom, holding on to his dorsal fin, my ancestors were never hurt or injured."

Related: How often do orcas attack humans?

Old Tom washed up dead in 1930, and his skeleton is kept at the Eden Killer Whale Museum. Isabella Reeves, a doctoral candidate at Flinders University in Australia, led the new study, and went to the museum to drill Old Tom's teeth and jaw for DNA. They first established Old Tom was male. That's unusual for orcas given his active role in the whale hunts — research has found male orcas tend to let their moms do the hunting. "The males are really lazy and just like to look pretty, basically," Reeves said.

Old Tom likely shared a common ancestor with New Zealand orcas. However, much of the variation in Old Tom's genome isn't present in the recorded DNA of any living population, meaning it was likely lost through extinction, the researchers found.

Most orcas had left Eden by the time Old Tom died and all but disappeared soon after. Thaua whalers originally hunted alongside orcas for subsistence, but the method became commercial under the Europeans. "Up until the point that relationship was commercialized, it was going okay," Reeves said.

Exactly when and how the human-orca relationship started is unknown. Stories passed down from generation to generation suggest that the Thaua people and other Aboriginals hunted with the orcas long before the Europeans started employing them to help with commercial operations in the 19th Century.

"We're pretty confident it had been going on for thousands of years," Reeves said. "But how it started is another question. I think what I've learned from killer whales is that they're curious, they can be strategic and when they want something, they know how to get it."

Some orca populations hunt baleen whales and feast on their tongues, but these orcas tend to target whale calves. Reeves noted that the orcas of Eden took down adults with the whalers, something they'd struggle to do alone.

Reeves said she's not sure people would believe the orcas of Eden story if it weren't for the "mind-blowing" photographic evidence from the time. "To imagine that happening now almost seems impossible," she said.

A ghostly white lump of rotten flesh in the shape of a mermaid recently washed ashore on an island in Papua New Guinea — and experts baffled.

The strange sea creature was likely a marine mammal, but its exact origins are unclear, experts told Live Science.

The mysterious mass was discovered Sept. 20 by locals on Simberi Island — a small volcanic island with a population of around 1,000 people in the Bismarck Sea in New Ireland Province, according to a Facebook post by New Irelanders Only (NIO). 

It is known as a globster — an unidentified organic mass that washes ashore. The origin of these mystery lumps is hard to pin down because much of the corpse has rotted away and most are missing body parts that have fallen off at sea. In this case, most of the creature's head and large chunks of its flesh are missing.

There is no information on the size and weight of the corpse because it was not properly measured before locals buried it, NIO representatives told Live Science. And no one collected DNA samples, which makes a proper identification almost impossible.

Related: 10 bizarre creatures that washed ashore in 2022 

Experts were also unable to identify it from the images alone. 

Helene Marsh, an environmental scientist at James Cook University in Australia, told Live Science it looks like a marine mammal. "After that it is anyone's guess," she added.

Sascha Hooker, a marine mammal expert at the University of St Andrews in Scotland, narrowed it down further. "It looks like a very decomposed cetacean to me," she told Live Science. Cetaceans, or whales and dolphins, are known to turn this color when their skin falls off, she added.

The most common cetaceans in the area are short-finned pilot whales (Globicephala macrorhynchus), spinner dolphins (Stenella longirostris), pantropical spotted dolphins (Stenella attenuata) and sperm whales (Physeter macrocephalus), according to a 2021 study in the journal Pacific Science. 

Erich Hoyt, a researcher at Whale and Dolphin Conservation in the U.K. and author of several books on cetaceans, agrees that the globster could be a small whale. However, he believes that it could also be a dugong, or "sea cow," that is known to graze on sea grasses in shallow waters in Papua New Guinea.

Other experts also suggested it could be one of the pudgy marine mammals, which have previously inspired stories of mermaids. "My best estimate is that it might be a Dugong," said Jens Currie, chief scientist of the Pacific Whale Foundation in Hawaii. Based on what's left of the head, it looks too wide to be a cetacean, he added. And "the amount of blubber also indicates a marine mammal and not a shark," Currie said.

But not everyone thinks that the globster was a marine mammal. 

Gavin Naylor, a marine biologist at the University of Florida who runs the International Shark Attack Files, thinks the remains could be from a large shark. Although "it is a little weird that all of the skin appears to have rotted off," he told Live Science. 

Other shark experts disagree.

"At first, I was leaning toward a large shark, but now that I've spent a bunch of time looking at this, I am more confident it is a cetacean" due shape of the tail and location of the flippers, said Gregory Skomal, a marine biologist at the University of Boston and head of the shark program at Massachusetts Marine Fisheries. The vertebrae, which are exposed in one of the images, also look more like a whale's backbone than a shark's cartilaginous spine, he told Live Science.

Skomal also spotted what "looks like a trachea," or windpipe, hanging from the animal near where its head was. If true, this would rule out a shark. 

But whatever it is, it has likely "been dead for weeks," Hoyt said.

Orcas have been harassing and toying with porpoises in the Salish Sea for 60 years, often to the point of killing them, but never eating them. Now, researchers think they know why.

The perplexing behavior, dubbed "phocoenacide" or "porpicide," often involves several orcas (Orcinus orca) tossing porpoises (Phocoenidae) around for up to five hours, traumatizing and sometimes killing their plaything.

"I always liken it to a group of friends in a swimming pool and they have a ball between them and the object is to keep the ball above the water," study lead author Deborah Giles, an orca researcher at the University of Washington and research director at the non-profit Wild Orca, told Live Science.

The orcas belong to a small and endangered population called southern resident killer whales that live off the Pacific coast of North America. They are fish-eaters, meaning it's unlikely they are playing with porpoises to consume them — deepening the mystery of why these orcas do it.

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

"In some cases, you can barely see that there was any interaction," Giles said. "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."

To find out why the orcas engage in this strange behavior, Giles and her colleagues pored over observational records from 1962 to 2020. Porpicide came and went in waves, Giles said, with orcas engaging in the behavior periodically and ditching it again, sometimes for several years. "It's considered a rare behavior, but when it happens, it's notable," she said.

There are 78 documented cases of southern resident orcas harassing often very young porpoises, with 28 cases resulting in death from "killer whale-induced trauma," the researchers wrote in the study, published Sept. 28 in the journal Marine Mammal Science.

Tossing porpoises around is almost certainly a form of social play, Giles said. But the aim of the game probably isn't to kill, as orcas sometimes continued throwing the porpoises around long after they had died. The activity may strengthen bonds between players and improve coordination and teamwork, according to a statement.

Playing with porpoises could also teach orcas valuable survival skills. Baby harbor porpoises (Phocoena phocoena) and Dall's porpoises (Phocoenoides dalli) are similar in size to the southern residents' favorite food — chinook salmon (Oncorhynchus tshawytscha) — so "it's possible that the whales are using it to learn how to chase fish," Giles said. 

Young orcas and their moms often play with porpoises together, in what could be hunting lessons. " Sometimes they'll let the porpoise swim off, pause, and then go after it," Giles said, which could test and fine-tune the orcas' coordination and prey-handling skills.

Female orcas may also get involved for another reason. Playing with porpoises might be an attempt to provide care for the small mammals, in what is known as a "mismothering behavior," according to the study.

This "might be due to their limited opportunities to care for young" of their own, Giles said in the statement. "Our research has shown that due to malnutrition, nearly 70% of Southern Resident killer whale pregnancies have resulted in miscarriages or calves that died right away after birth."

The southern residents' porpicidal tendencies remain somewhat mysterious, Giles said, but the behavior appears to have spread through the population and across generations over the past 60 years. 

"It is possible that porpoise harassing and killing behavior was spread via social learning," the researchers wrote in the study.

Scientists in Russia discovered seven perfectly intact sea otters in the belly of a beached orca, according to a new study. The doomed killer whale was found far from its normal hunting grounds, raising the question of what it was doing there.

The female orca (Orcinus orca) was found in 2020 on the coastline of one of the Commander Islands, which lie offshore the Russian Far East in the Bering Sea. Scientists performed a necropsy on the animal and discovered not only the seven dead sea otters (Enhydra lutris), which collectively weighed 258 pounds (117 kilograms), but also 256 cephalopod beak parts. 

Related: Opportunistic orcas have developed a new feeding behavior that appears to be killing them

One sea otter was lodged between the oral cavity and the esophagus, which may have led to the whale's demise, the researchers wrote in the study, which was published Sept. 28 in the journal Aquatic Mammals. 

Several things about the killer whale have puzzled the researchers.

"It is very unusual because orcas don't normally eat sea otters," study co-author Olga Filatova, a cetacean researcher at Moscow State University, told Live Science in an email. 

Instead, they hunt seals, sea lions, dolphins and even other whales. And whatever prey species they hunt, "they normally don't swallow prey whole — they usually tear it apart and eat only the best (most fatty) parts," Filatova said.

Gulping down whole sea otters was likely challenging for the doomed orca, as adult sea otters can reach up to 5 feet (1.5 meters) long. The researchers think the orca may have taken this extraordinary step because it was starving. 

The researchers also analyzed the orca's DNA and determined that this individual was part of a population, known as "Bigg's killer whales," that have a vast home range that stretches from the Aleutian Islands and the Gulf of Alaska, to the coastline of California.

This is the first time any member of this orca population has ever been found in the Western Pacific, leading the study authors to hypothesize that the orca learned this hunting strategy elsewhere. Feeding strategies are usually passed on from mothers to calves, the study authors noted. 

While the stranded orca raises some questions, it may help answer others. For some time, sea otter populations between the Aleutian Islands and the Gulf of Alaska have dwindled. 

While some scientists suspected orcas were behind the area's decreasing sea otter population, this is the first direct evidence of an orca originally from that region preying on sea otters. The finding raises the possibility that orca predation may be behind the drop in sea otters.

A record number of orcas have died this year after snacking on fish hauled up by commercial trawlers in Alaska but then getting entangled in fishing gear, according to the National Oceanic and Atmospheric Administration (NOAA).

Fishers have linked the increase in mortality to a "new behavior," in which orcas — also known as killer whales — feed in front of nets that fishers simultaneously pull to the surface.

"In 2023, our captains have reported an increase in the number of killer whales present near our vessels," the Groundfish Forum, a Seattle-based fishery trade association that oversees activities on 19 trawlers in North Pacific waters, said in a statement. While orcas are known to flock to fishing sites to feast on the catch, "marine mammal scientists are not sure why this change has occurred."

Orcas (Orcinus orca) are highly intelligent and innovative marine mammals that can imitate and learn from each other through a process called social learning. Orcas are known to exploit human fisheries, which provide them with all-you-can-eat buffets worldwide, according to a 2022 NOAA Fisheries report. Longline fisheries, which dangle lines of baited hooks to catch various fish species, are particularly attractive, as orcas can easily pluck food off the hooks.

Related: Inbreeding may be causing orca population in the Pacific Northwest to crash 

Research has shown that poaching from fisheries is a behavior that can spread through orca populations via social learning.

This opportunistic feeding behavior occasionally leads to entrapment, injury and, in some rare cases, death. Five orcas were caught and died in fishing gear in the five-year period between 2016 and 2020, according to the report.

But since January, the number of orcas that have died tangled up in nets off the coast of Alaska has been higher. In a statement published Sept. 21, NOAA Fisheries said groundfish trawlers operating in the Bering Sea and off the Aleutian Islands in the North Pacific have accidentally trapped 10 orcas in fishing gear so far this year. Only one animal was released alive, the agency said.

For the other nine orcas, "NOAA Fisheries is analyzing collected data to determine the cause of injury or death and determine which stocks these whales belong to through a review of genetic information," the statement said.

The agency is also reviewing information regarding an orca incidentally caught during the Alaska Fisheries Science Center's annual longline survey this summer, as well as the death of an orca found entangled in fishing gear on the Central Bering Sea slope on June 7.

Scientists hope the findings will shed light on the spike in orca injuries and deaths observed this year and help them develop guidelines to protect the animals.

Orcas are long-lived and reproduce slowly, so the accidental removal of a few individuals by fisheries may put the overall population at risk. In the Bering Strait, orcas are protected under the Marine Mammal Protection Act of 1972, which requires boat owners and operators to report to NOAA Fisheries any injuries or deaths that occur during fishing or survey operations.

"Our vessels are changing the way we operate to try to avoid whales, including moving our vessels when whales are encountered and voluntarily stopping fishing operations this year in fisheries where killer whale mortalities occurred," Groundfish Forum, whose vessels have been involved in several fatal encounters with orcas this year, said in their statement.