The Guam Rail

Even though I would consider myself "hip" to the Birds Aren't Real movement, I have come to the conclusion that not only is the Guam Rail (named ko'ko' in Guam) real, it is my favorite bird of all time.

This week we were able to take a Zoom virtual tour of the Small Animal Facility on campus, and the person giving the tour was able to enter one bird's cage. That bird was adorable and inquisitive, pulling at the shoelaces of our tour guide and jumping on the shoulder of his keeper. For as much research I had already done on the species, I loved them even more.

via the Smithsonian National Zoo

Look at this bird. How can you not love this round, flightless bird?

The guam rail is the second species of bird to come back from being extinct in the wild. Under threat from the invasive brown tree snake, their numbers started crashing. In 1981, there were an estimated 21 birds living in the wild, a steep decline from the estimated 10,000 birds prior to the 1960s. Around that time, the rest of the birds were taken into captivity and were thereby extinct in the wild.

The brown tree snake made its way to Guam via cargo ships between 1944 and 1952. Prior to this invader, there were no snakes in Guam and so the animals there had not developed any defences against the predators. Native species began to decline, resulting in the disappearance of 10 of the 12-13 Guam bird species.

Captive breeding programs began then as a collaboration between the Smithsonian, the Guam Division of Aquatic and Wildlife Resources (DAWR), the US Fish and Wildlife Service (USFWS), and AZA accredited zoos via a species survival plan (SSP). The birds were then bred for reintroduction in a way to maintain as much genetic diversity as possible.

Successful reintroduction has been completed at two islands, Rota and Cocos, off the mainland. Rota was a snake-free island and Cocos was infested with invasive rats, rather than the invasive snake, and the rats were culled before reintroduction was attempted. Cocos is uninhabited other than a day resort on one side of the island and supplied an area free from human threats.

Back in March, the first invasive brown tree snake was spotted on Cocos island. A larger population was then found on the island, and scientists have been working on figuring out how they got there and how to control the population before they threaten the birds once more.

This species is only the second bird species to be downgraded from "Extinct in the Wild" to "Critically Endangered" on the IUCN Red List, and is an incredible conservation success stories that also illustrates just how dangerous invasive species can be. Hopefully the population of brown tree snakes on Cocos island can be eliminated, quickly, and efforts to at least decrease the population of the snakes in other parts of Guam need to be taken to restore the guam rail to its former habitat range.

Current reintroduction efforts for these birds are on hold due to the pandemic, but consider supporting these efforts through donations or by simply sharing the story of these adorable flightless birds.