The bald eagle is a large raptor. The adults have the characteristic white head and tail and dark brown body. Juveniles are completely dark brown and do not develop the white feathers until the fifth or sixth year. Adults average three feet tall, weigh ten to twelve pounds, and have a wingspan of seven feet.1 Females are generally larger than males. The eagles mate for life, or until the death of their mate. Bald eagles may live up to thirty years in the wild.2
The southwestern bald eagle is found on rivers with an adequate prey base and nesting area. The home ranges generally exceed two miles along the river and half a mile wide on each side of the nest. The eagles build their nests in trees, cliffs, or pinnacles near the river.3
The southwestern bald eagle historic range cannot be accurately determined. The current range extends through Oklahoma and Texas west of the 100th meridian, all of New Mexico and Arizona, and California along the border of the Lower Colorado River. The eagle may also range into Baja California and parts of mainland Mexico.
The bald eagle has been proposed for delisting, but still recieves full protection under the Endangered Species Act.
The eagle feeds largely on four kinds of fish: channel catfish, carp, Sonora sucker, and the desert sucker. Rabbits, coots, and other small mammals, birds, and other fish also make up part of the bird's diet.
Breeding pairs begin nesting in November or December. The nest may be used year after year, eventually reaching nine feet in diameter and weighing as much as 2,000 pounds.2 Two to three eggs are laid from January to March. The eggs hatch from February to April. The eaglets spend up to two months in the nest and four to six weeks on the home range before dispersing.
The Southwestern Bald Eagle in Pima County:
n January of 2002, a bald eagle took up residence on the nothwest side of Tucson. The eagle, a very rare visitor to the Tucson area, was electrocuted by utility lines at the end of February 2002.
1. U.S. Fish and Wildlife Service Division of Endangered Species. Bald Eagle Species Account. 9/27/99 Website: http://www.fws.gov/r9endspp/i/b/msab0h.html
2. U.S. Fish and Wildlife Service. 1982. Bald Eagle Recovery Plan (Southwestern Population). U.S. Fish and Wildlife Service, Albuquerque, New Mexico. 65pp.
3. Woodland Park Zoo Animal Facts. 9/24/99 Website: http://www.zoo.org/educate/fact_sheet/eagle/eagle.htm