Only three native species left in the wild

Audio Samples of Guam Birds
Guam Birds Part A – D

The limestone and ravine forests of Guam have historically supported 14 species of terrestrial birds. Two of these 14 birds are endemic to Guam at the species level. Five bird species are endemic at the sub-species level. One of the endemic species is now extinct. Seven have been extirpated from the island.

The loss of these birds is believed to be largely a result of habitat alteration and the effects of the introduced brown treesnake. Three species are still living in the wild. Three species are being held in captive breeding programs on Guam and zoos in the United States mainland. Others are found in the Northern Mariana islands.

The two endemic species are by definition unique to Guam. The Guam flycatcher, also called the Guam broadbill, and the Guam rail are not naturally found anywhere else in the world. CHuguangguang, the Guam flycatcher, was last seen in 1985 and is now believed to be extinct. Ko’ko’ the Guam rail, a flightless bird, extinct in the wild, has been successfully bred in captivity. An experimental population of Guam rails has been released on Luta (Rota), an island 40 miles north of Guam in the Northern Marina islands. Another 70 ko’ko’ live on Dåno’ (Cocos Island) off the coast of Malesso’. There is a partnership with the American Zoo Association and the Guam Division of Aquatic and Wildlife Resources for the captive rearing program. As of 2019, there are more ko’ko’ in the wild than captive ones. Although there are ko’ko’ living in the wild on Dåno’ and Luta, its status of “extinct in the wild” will not be changed until wild populations are established on Guam.

The taxonomic designations of species and sub-species vary among researchers and are continuously being updated and changed. Those used in this article are the most currently available. Bird names given to subspecies indicate the subspecies is endemic to Guam.

The yellow bittern and nightingale reed-warbler are not strictly inhabitants of dry land terrestrial habitats. They have also occupied some wetland locations.

By Gretchen R. Grimm, MS

Birds of Guam entries

  1. Bridled White-Eye (Nosa’)
  2. Guam Flycatcher (CHuguangguang)
  3. Guam Rail (Ko’ko’)
  4. Mariana Crow (Åga)
  5. Mariana Fruit Dove (Totot)
  6. Mariana Gray Swiftlet (Yǻyaguak)
  7. Micronesian Honeyeater (Égigi)
  8. Micronesian Kingfisher (Sihek)
  9. Micronesian Megapode (Sasangat)
  10. Micronesian Starling (Såli)
  11. Nightingale Reed-Warbler (Gå’ga’ Karisu)
  12. Rufous Fantail (CHuchurika/Naabak)
  13. White Throated Ground Dove (Male: Paluman Ǻ’paka’, Female: Paluman Fache’)
  14. Yellow Bittern (Kakkak)

For further reading

Jenkins, J. Mark. The Native Forest Birds of Guam. Ornithological Monographs No. 31. Washington, DC: American Ornithologists’ Union, 1983.

Pratt, H. Douglas, Philip L. Bruner, and Delwyn G. Berret. A Field Guide to the Birds of Hawaii and the Tropical Pacific. New Jersey: Princeton University Press, 1987.

Savidge, JA. “Extinction of an Island Forest Avifauna by an Introduced Snake.” Ecology 68, no. 3 (1987): 660-668.

US Fish and Wildlife Service. “Birds.”  Pacific Islands Fish and Wildlife Office Exploring Species.

Vice, Daniel S., and Mikel E. Pitzler. “Management of the Yellow Bittern (Ixobrychus sinensis) on Guam to Minimize Threats to Aviation Safety.” Paper presented at the Bird Strike Committee-USA/Canada, First Joint Annual Meeting, Vancouver, May 1999.

Wiles, Gary J. “A Checklist of the Birds and Mammals of Micronesia.” Micronesica 38, no. 1 (2005): 141-189.


EndemicNative to a particular environment.
ExtirpatedSpecies that have become locally extinct.