Guam Rail Gallirallus owstoni Scientific name definitions

28 cm; male 174–303 (241) g, female 170–274 (220) g. Virtually flightless; can fly for only 1–3m; tail very short and decomposed; toes very short. In fresh plumage, has indistinct, dull olive-buff breast band which becomes abraded to leave breast clear grey; some individuals have pronounced reddish tinge on nape. Sexes alike but female smaller. Darker than H. philippensis and lacks chestnut on face , breast and usually nape; black and white barring on more remiges, decreasing from extensive, bold barring on outer primaries to narrow barring on secondaries as brown of feather centres becomes broader; uniform brown upperparts with no spots or bars; black bill with grey base. Duller underparts than H. rovianae and has different facial pattern and more extensive white wing markings. Juvenile similar to adult but with less extensive areas of grey on neck, breast and supercilium.

Introduced to nearby Rota I, and recently (2011) to Cocos I (off S Guam) (1 BirdLife International (2013). IUCN Red List for birds. URL: http://www.birdlife.org (download Aug 2013). Close ).

Guam (extinct in wild).

Snails, slugs, insects (Orthoptera, Dermaptera and Lepidoptera), geckos and some vegetable matter; also fish, tomatoes, melon, palm leaves, and carrion, e.g. amphibians crushed by cars. Introduced giant African snail (Achatina fulica) became an important food when it expanded its range into most of the island's habitats. Takes food items from ground surface; chases low-flying insects, especially butterflies; takes seeds and flowers from low grasses and shrubs, stretching up to reach items 40cm above ground. Often forages along field edges and roadsides, but seldom far from cover. Most active at dawn and dusk; also forages at night.

During breeding season makes loud penetrating screeches “keee-yu”; also a series of short “kip” notes.

EXTINCT IN THE WILD. In past, widely distributed and abundant, although taken by local people with dogs and snares, and despite presence of introduced predators such as feral pigs and cats. Before 1960s population was estimated as 10,000s; declined rapidly during 1970s, along with most other indigenous birds, as a result of the spread throughout the island of the introduced brown tree snake (Boiga irregularis); by 1981 population reduced to c. 2000 birds, by 1983 to less than 100, and species became extinct in the wild by 1987. In 1983 a captive breeding programme was set up, and c. 180 breeding birds are now located on Guam and in 16 zoos in USA . Captive breeding has been very successful, the founding birds showed surprisingly good genetic diversity, and efforts are being made to establish a self-sustaining experimental population on the snake-free island of Rota in S Northern Mariana Is; action also being taken to extirpate brown tree snake from Guam, so as to permit reintroduction there; birds released on Rota recently bred for first time (reported 1996), and further introductions planned in order to bolster population on Rota.