Historically on the island of Guam in the Pacific Ocean, now only on the island of Rota as an introduced population.


Forest, grassland, mixed woodland and scrub, and fern thickets

Betcha can't find me!

Little is known about the secretive and territorial Guam rail. Why? Because there are so few of them in the wild! We do know that rails are very good at walking, or even running, without making any noise, even when moving through thick vegetation. Besides being able to move silently, they seldom vocalize, although the bird responds to other rails, loud noises, or other disturbances with a loud, piercing whistle or series of whistles.

Fly? Sorry, I'm afraid of heights!

The Guam rail, like other island rails, is virtually flightless. This is probably because there were no natural predators on its native island to bother them. While they do not have much in the way of flight muscles, they do have well-developed leg muscles. They can swim, dive, and even sink, using their wings underwater.

Guam rails can fly only about 3 to 10 feet (1 to 3 meters) at a time.
In their native Guam, Guam rails are called Ko'Ko'.

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 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. San Diego Zoo Global is participating in both the breeding programs and current reintroduction programs on Guam and nearby Rota Island.

Join us!
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.