Animalia > Chordata > Aves > Gruiformes > Rallidae > Gallirallus > Gallirallus owstoni

Gallirallus owstoni (Guam Rail)

Synonyms: Rallus owstoni

Wikipedia Abstract

The Guam rail (Gallirallus owstoni) (Chamorro name: ko'ko' ) is a species of flightless bird, endemic to the United States territory of Guam. The Guam rail disappeared from southern Guam in the early 1970s and was extirpated from the entire island by the late 1980s. This species is now being bred in captivity by the Division of Aquatic and Wildlife Resources on Guam and at some mainland U.S. zoos. Since 1995, more than 100 rails have been introduced on the island of Rota in the Commonwealth of the Northern Mariana Islands in an attempt to establish a wild breeding colony. Although at least one chick resulted from these efforts, predation (largely by brown tree snakes and feral cats) and accidental deaths have been extremely high. A small number of birds potentially persists.
View Wikipedia Record: Gallirallus owstoni

Endangered Species

Status: Extinct in the wild
View IUCN Record: Gallirallus owstoni

EDGE Analysis

Uniqueness Scale: Similiar (0) 
 Unique (100)
Uniqueness & Vulnerability Scale: Similiar & Secure (0) 
 Unique & Vulnerable (100)
ED Score: 4.93445
EDGE Score: 4.55336


Adult Weight [1]  226 grams
Female Weight [1]  212 grams
Male Weight [1]  241 grams
Weight Dimorphism [1]  13.7 %
Diet [2]  Carnivore (Invertebrates), Carnivore (Vertebrates), Piscivore, Frugivore, Herbivore
Diet - Ectothermic [2]  10 %
Diet - Fish [2]  10 %
Diet - Fruit [2]  20 %
Diet - Invertibrates [2]  30 %
Diet - Plants [2]  20 %
Diet - Scavenger [2]  10 %
Forages - Understory [2]  30 %
Forages - Ground [2]  60 %
Forages - Water Surface [2]  10 %
Incubation [3]  19 days


Name Countries Ecozone Biome Species Report Climate Land
Marianas tropical dry forests Micronesia Oceania Tropical and Subtropical Dry Broadleaf Forests    

Biodiversity Hotspots

Name Location Endemic Species Website
Polynesia-Micronesia Fiji, Micronesia, Polynesia, Samoa, Tonga, United States Yes

Emblem of


Institutions (Zoos, etc.)



External References



Attributes / relations provided by
1Jenkins, JM (1979) Natural history of the Guam Rail. Condor 81: 404-408
2Hamish Wilman, Jonathan Belmaker, Jennifer Simpson, Carolina de la Rosa, Marcelo M. Rivadeneira, and Walter Jetz. 2014. EltonTraits 1.0: Species-level foraging attributes of the world's birds and mammals. Ecology 95:2027
3del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
Ecoregions provided by World Wide Fund For Nature (WWF). WildFinder: Online database of species distributions, ver. 01.06 WWF WildFINDER
Biodiversity Hotspots provided by Critical Ecosystem Partnership Fund
Abstract provided by DBpedia licensed under a Creative Commons License