Guam Rail (Rallus owstoni) – The Rarest Rail Species
Eight of the world’s 124 species of rail are threatened by disappearing marshland habitat and introduced competitive domestic or predatory mammals. A few struggles on in the wild in tiny numbers but Guam rail (Rallus owstoni) is the only species whose entire population (just 33 birds in 1986) is confined to captivity.
Guam is a USA territory in the Pacific, about midway between Japan and New Guinea. The Australian brown tree snake and the Philippine rat snake, both bird and egg eaters, have been introduced to Guam since World War II and are now thought to be the main cause of a dramatic decline in native forest birds. Human disturbance of the island has also been great.