スミソニアン国立動物園のインスタグラム(smithsonianzoo) - 1月31日 23時06分

The Guam rail, referred to locally as the ko'ko', was once a common bird with an estimated 60,000 to 80,000 birds in Guam during the late 1960s and early 1970s. However, the species was almost lost entirely due to predation by the invasive brown tree snake (Boiga irregularis). After being extinct in the wild for more than 30 years, the birds are living on snake free islands and their status has been upgraded to critically endangered!

There are no large snakes native to Guam, so the birds, or avifauna, that lived there did not stand a chance against the arboreal predators. In a relatively short time period, the snake spread across the island and wiped out 10 of the 12 species of forest birds, several of which were endemic.

The brown tree snake also caused the disappearance of six of 11 native lizards and two of three native bat species.
Guam’s birds are like gardeners. As they move through the forest, they disperse the seeds of the fruit and plants they consume. When the birds began disappearing, so did the forest. There is now less diversity in the species of trees that grow and the forests are thinning. Although trees have suffered, spider populations have exploded because there are no birds to prey upon the insects.
The effort to save the Guam rail began in the early 1980s when biologists from Guam’s Department of Aquatic and Wildlife Resources captured the last 17 birds to start a breeding and recovery program. One of the first transfers of birds from Guam to the mainland United States occurred in 1985, when 12 birds were brought to the Smithsonian Conservation Biology Institute.

The first bird releases on Rota, which does not have brown tree snakes, were in 1989 to 1990. Now there are around 200 birds living on the island, and more importantly, they are producing their own offspring.

Though it may seem like 200 Guam rails in the wild is not very many, they symbolize hope for the species. Guam DAWR and their partners will continue to work with the 170 birds still in human care to hatch more chicks that will be candidates for release on Rota and Cocos Islands. #Guam #GuamRail #Koko #Birds #WeSaveSpecies #EarthOptimism

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