The San Diego Zoo received its first Guam rails in 1968 for the purpose of observation and scientific study. We then participated in a breeding program with the goal of providing birds for reintroduction or relocation to their native islands.
Today, the San Diego Zoo Safari Park has a small group of Guam rails in our off-exhibit Bird Breeding Complex.
Prior to the 1960s, there were probably around 10,000 Guam rails living on Guam, a South Pacific island. Sometime between 1944 and 1952, brown tree snakes Boiga irregularis arrived on Guam, most likely on cargo ships. The snakes’ population rapidly increased, because there was lots of prey (such as the Guam rails) and no natural predators. Prior to the tree snakes’ arrival, there were no snakes on Guam, so the rail, like other native animals there, had not developed natural defenses against this predator. The tree snakes wiped out the native animal populations, and by the 1970s, 9 of the 11 native bird species, including the Guam rail, had disappeared.
Trying to save the species, the last few birds were removed from the island in the 1980s. In 1989, reintroduction of these birds began on the island of Rota, near Guam, as part of the Association of Zoos and Aquarium’s Species Survival Plan for the species. It is hoped that controlling the feral cat population on this island will help with the Guam rail’s success there. San Diego Zoo Global is participating in both the breeding programs and current reintroduction programs on Guam and nearby Rota Island. Some of the rails now living in the wild were raised at our facilities.
You can help us bring Guam rails and other bird species back from the brink by supporting the San Diego Zoo Global Wildlife Conservancy. Together we can save and protect wildlife around the globe.