The U.S. Fish and Wildlife Service has reviewed a petition to designate the Sonoran Desert-nesting population of the bald eagle as a distinct population segment and reclassify the population from its current threatened status to endangered. The Service concluded the petition did not contain substantial scientific data to warrant the actions.
The Service made the determination in response to a petition received in October 2004 from the Center for Biological Diversity, Maricopa Audubon Society and Arizona Audubon Council. While the Endangered Species Act allows protection of distinct population segments some species, in order for the Service to do so it must be demonstrated that the population is discrete from other members of its species, and that the discrete population is significant to the species as a whole.
"While bald eagles in the Sonoran Desert have attributes that make them discrete, the petition doesnt present substantial scientific information that they are significant in relation to the whole species," said Steve Spangle, Arizona Field Supervisor. "In addition, the level of threats described in the petition, as well as information available from the Arizona Game and Fish Department, doesnt indicate that the Sonoran Desert bald eagle population is at risk of extinction."
The Service also conducted a thorough analysis of the threats to the Sonoran Desert population using the same criteria to list any species, subspecies, or distinct population segment. The Endangered Species Act identifies five factors to be considered, either singly or in combination, to determine whether a species may be threatened or endangered. They are: (A) present or threatened destruction, modification, or curtailment of habitat or range; (B) overutilization for commercial, recreational, scientific, or educational purposes; (C) disease or predation; (D) inadequacy of existing regulatory mechanisms; or (E) other natural or manmade factors affecting its continued existence.
The bald eagle is currently at its highest number ever recorded in Arizona despite the threats presented in the petition.
In the desert Southwest, bald eagles breed and forage in close proximity to a variety of aquatic habitats, including reservoirs, regulated river systems, and free-flowing rivers and creeks. Eagles place their nests mostly on cliff edges, rock pinnacles and in cottonwood trees. Upon fledging, Sonoran Desert bald eagles emigrate to northern U.S. and Canada, but return to reside in the Southwest once reproductively mature. Breeding pairs in the Sonoran Desert establish breeding territories in December or January and lay eggs in January or February, earlier than bald eagles in northerly areas. Numerous northern-nesting bald eagles winter in the Southwest.
Nationally, the bald eagle is recognized as a threatened species and the Service has proposed to remove it from the list of species protected under the Act. The species is also protected under the Bald and Golden Eagle Protection Act and the Migratory Bird Treaty Act. There are presently 50 bald eagle breeding areas in Arizona and an estimated 166 eagles in the state. Currently in the lower 48 states, there are approximately 7,066 breeding pairs of bald eagles, up from an estimated 417 pairs in 1963.
A copy of the finding about the bald eagle is available on the Internet at www.fws.gov/arizonaes/, by contacting the Arizona Ecological Service Field Office at 602/242-0210 or at 2321 W. Royal Palm Road, Suite 103, Phoenix, AZ 85021.
