’Extinct’ bird rediscovered in Mexico

Scientists thrilled by first confirmed sighting in almost a decade

The Cozumel Thrasher (Toxostoma guttatum), a bird not seen or recorded by scientists for close to a decade and thought by some to have gone extinct, was sighted last month by a team of field biologists, American Bird Conservancy and Conservation International announced today. Its rediscovery immediately makes it the single most threatened bird in Mexico.

The Cozumel Thrasher, an endemic bird found only on the island of Cozumel off the Yucatan Peninsula in Mexico, appears to have experienced a precipitous decline in 1988 after Hurricane Gilbert tore through the island. It immediately became rare, but small numbers of the bird were known to exist until it was last sighted in 1995. That same year, Hurricane Roxanne ripped through Cozumel and may have also contributed to the species’ decline. Scientists estimate that as many as 10,000 once thrived on the island.

Previous recent expeditions to find the Cozumel Thrasher proved futile. Last month, a team of field biologists working in conjunction with Villanova University and the Mexican counterpart of the Island Endemics Institute, spotted a single individual, confirming that the species was not yet extinct. The field biologists were on a rediscovery mission sponsored by American Bird Conservancy and Conservation International.

“This is terrific news for the species,” said Dr. George Wallace, vice president for International Programs at American Bird Conservancy. “It opens a door to a range of possibilities that we hope will lead to the establishment of a protected area if more birds are found.”

The Cozumel Thrasher is a medium-sized (23 cm. long) bird, similar to a mockingbird. It is brown and white with a long, curved bill. Its upper parts are a rich chestnut-brown with two white wing-bars. It has a gray face, black bill and legs, and white underparts heavily streaked black. Its song is described as a complex scratchy warbling.

“The rediscovery of the Cozumel Thrasher is a reminder of two key things: the importance of tropical islands for biodiversity conservation, and the importance of never giving up on a species – no matter how rare,” said Dr. Russell Mittermeier, president of Conservation International.

Although the hurricanes are believed to have had a major negative impact on the birds, scientists believe that other factors must have contributed to the decline, because the Cozumel Thrasher likely survived hurricanes for millennia. Introduced species, especially predatory boa constrictors introduced to the island in 1971 and now abundant, may also have had a disastrous effect.

Fortunately, large tracts of deciduous and semi-deciduous forest, thought to be the species’ preferred habitat, still remain, and the birds are not hunted or trapped for the pet trade. Formal protection and management of Cozumel’s habitat could benefit other species on the island, including two other endemic bird species, fifteen endemic bird subspecies, and at least three endemic and threatened mammal species.

The team will next try to determine the size and range of the population represented by this single bird, and then return next January, when the birds are known to sing more frequently, to attempt further surveys. To protect this and potentially other birds from disturbance, the exact location of the discovery is not being disclosed to the public.