Guam Rail
After habitat destruction, introduced species are the
second greatest threat to the world’s birds. The
Pacific island of Guam provides a textbook example of
the perils posed by exotic species. In the late 1940s,
brown tree snakes (Boiga irregularis) found
their way, most likely via military equipment, to the
remote island. Since then, the serpents have thrived,
and eaten the island’s native birds, reptiles,
and other wildlife in many cases out of existence. The
once-plentiful Guam rail (Gallirallus owstoni),
a flightless bird, had nowhere to hide.
In the 1980s, Zoo scientists helped to corral the last few birds and to start a zoo breeding program. This last-ditch effort probably saved the species. Guam rails breed well in zoos, and the current world zoo population is about 200. In 1989, Guam rails were introduced to the nearby snake-free island of Rota, and this population now appears to be established and increasing. Rails are now being released into the wild on Anderson Air Force Base in northern Guam in an area where brown tree snakes are being actively controlled. This effort was initiated after a 1997–1999 pilot project on Guam demonstrated successful reproduction within a 150-acre enclosure where snakes were being culled.
 |
(Jessie
Cohen/NZP) |
ZooGoer 32(2) 2003.
Copyright 2003 Friends of the National Zoo.
All rights reserved.
