Critically endangered hare spotted in surprising location for the first time in 40 years — but it was already dead

For the first time in four decades, scientists have announced a confirmed sighting of a critically endangered hare in part of its native range, after spotting its completely flattened carcass on a roadside.

Researchers were traveling for fieldwork on Hainan, an island in southern China, when one member spotted the roadkill by chance. Despite the carcass's severely damaged condition, they immediately recognized it as the little-known Hainan hare (Lepus hainanus). The species, which is found only on Hainan, is among the world's most understudied lagomorphs, the mammal group that includes rabbits, hares and pikas.

The sighting occurred around 125 miles (200 kilometers) from the hare's only current known range in the island's northeast, according to a study published Dec. 15, 2025, in the journal Mammalia.

Although the hare is known to survive in some areas of western Hainan, particularly the Datian National Nature Reserve, the roadkill incident represents the first confirmed documentation of this species from northeastern Hainan since 1986, suggesting that an overlooked remnant population still exists in the region, according to the study.

"It provides hope for this nationally critically endangered species as its current range is wider than previously known," study first author Michael Hui, a conservation officer with the Hong Kong-based conservation group Kadoorie Farm and Botanic Garden (KFBG), told Live Science via email. "However, our article also provided updated information regarding the species' stronghold in the western region, which is not as secure as traditionally assumed."

Historically, L. hainanus is thought to have been widespread and abundant across most of Hainan's coastal lowlands, primarily in the northwest, west and south, according to the study.

In the 1950s, the species' population is thought to have been around 10,000 individuals. But a particularly sharp decline was observed in the 1970s and '80s, largely due to habitat loss and excessive hunting for their meat and fur.

A 2008 report estimated that there were likely no more than 250 to 500 individuals remaining on the island. Concerns over its status recently led to the Hainan hare being designated as a "critically endangered" species on China's Red List.

Outside Datian National Nature Reserve, the species is rarely reported, and even inside the reserve, everyday sightings are generally infrequent, Hui said. A recent "rapid survey" covering most of the hare's historical range in western and northwestern Hainan documented only one live individual and noted that the species was disappearing unnoticed. But a lack of systematic, island-wide survey data from the past few years means the total population is unknown.

L. hainanus is elusive, in part because it's nocturnal and most of its preferred lowland habitats lie outside protected areas, which have traditionally received little research attention, Hui said.

"We believe that every new record, even single incidental records, can help inform future surveys and proposed conservation actions," the authors wrote in the study.

Much of the hare's habitats are declining because of agricultural expansion and urban development. Therefore, an island-wide survey to understand its current status, distribution and threats is crucial for making informed conservation decisions, the study authors said.