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 fourteen species of terrestrial birds. Two of these fourteen 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. Chuguanguan, 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 Rota, an island forty miles north of Guam in the Northern Marina islands.

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

For further reading

Guam Department of Agriculture Division of Aquatic and Wildlife Resources “Fact Sheet: Bird of Guam.” (accessed August 12, 2010).

Pratt, H.D., P. L. Bruner, and D. G. Berret. The Birds of Hawaii and the Tropical Pacific. Princeton: Princeton University Press, 1987.

Savidge, J.A. “Extinction of an Island Forest Avifauna by an Introduced Snake.” Ecology 68 (1987): 660-68.

Smithsonian National Zoological Park “Fact Sheets: Where Have the Birds of Guam Gone?” (accessed August 12, 2010).

U.S. Fish and Wildlife Service “Pacific Islands- Endangered Species: Guam Rail.” (accessed August 12, 2010).

Vice, D.S. and M. 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, BC, 1999. Also available online at Digital Commons @ University of Nebraska – Lincoln: Bird Strike Committee Proceedings (accessed August 12, 2010).

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

Glossary

Endemic: Native to a particular environment.

Extirpated:Species that have become locally extinct.