|
|
Northern Bald Eagle
Haliaeetus leucocephalus
| Size |
Its body is 30-40 inches in length and its wingspan can be over 6 ft. |
| Weight |
The northern bald eagle weighs 8-16 pounds. |
| Conservation Status |
|
| Diet |
In the wild, northern bald eagles eat fish, frogs, small mammals, insects, birds, carrion and occasionally snakes. This diet will vary seasonally depending on what is available. For instance, eagles will often eat a lot of carrion in the winter.
In the Zoo, the northern bald eagle eats horsemeat, rats, chickens, bones, fish and quail.
|
| Geographic Range |
The northern bald eagle may be found in much of the contiguous United States, Alaska and Canada. While the northern subspecies is more numerous, the southern bald eagle subspecies can range as far south as northern Mexico. |
| Where to find me in the Zoo |
Bald Eagle Exhibit |
Note: Description below should include Longevity, Behavior, and Reproduction information
Female bald eagles are larger than males. The bald eagle's body feathers are brown-black in color, and their head and tail is a brilliant white. They are fish eagles with powerful talons for seizing fish as they skim the surface of the water.
Northern bald eagles inhabit coastal areas, mountain ranges, rivers and lakes. They prefer areas near water.
Although it is not known for certain, northern bald eagles are estimated to live up to about 30 years in the wild. The oldest documented bald eagle in captivity was 47 years old.
Eagles mate for life and make excellent parents. They reach sexual maturity at 4-5 years. Their nests can be 5 feet wide and over 2 feet tall. These nests are made from sticks and are typically reused by adding more sticks to it each year. Females lay one to three eggs in these nests, and the chicks hatch after aproximately 35 days of incubation. Both females and males care for the chicks and take turns in hunting and bringing back food back to their young. The young fledge from the nest at about 12 weeks of age.
Eagles travel by soaring and gliding on thermals. They can cover great distances without flapping their wings. They have elaborate airborne courtship "dances," during which they perform a breathtaking display of diving, soaring, rolling and gyrating. Bald eagles are aggressive hunters but will often scavenge dead prey or even steal it from another bird when the opportunity arises.
The eagle's wing is light in weight but incredibly strong. They have powerful feet, sharp talons and spiny pads on the bottoms of their talons to snatch and grasp prey. The beak is curved and very powerful for tearing meat. The bald eagle's visual acuity is very high, but its night vision is poorly developed.
Ritz: Received on November 23, 1993 from a wildlife rehabilitator in Minnesota. Ritz could not be released back into the wild due to chronic problems with the growth of his feathers that leave him flightless for periods of time.
Glory: Received on June 8, 2004 from the National Aviary in Pittsburgh. Glory could not be released back into the wild due to a left wing injury.
Enrichment
Adoption Information
Featured Foster Parent
According to CITES I, bald eagles are listed as most restricted and threatened with extinction. Currently, this species is recovering well.
Once abundant throughout the continental U.S. and Alaska (which holds the highest number of eagles in the country today), eagle populations had started to decline due to human disturbance of their habitat and hunting?they were seen as competition for resources like salmon in Alaska. This prompted the passing of the Bald and Golden Eagle Protection Act in 1940, which reduced people's harassment of eagles and began a slow recovery of the population numbers.
The introduction of DDT disrupted this recovery, though, as eagles consumed fish and small mammals that had ingested the insecticide. Widespread use of DDT began in the 1930s and became increasingly popular in the 1960s.
Bald eagles were declared an endangered species in 1967 under a law that preceded the Endangered Species Act. On July 4, 1976, eagles were officially listed under ESA as an endangered species, affording the bald eagle protection through the act. In 1995, they were upgraded to threatened status. On June 28, 2007 the species was removed from the ESA list of endanged and threatened species all together.
Zoo Research
To aid the recovery of bald eagles, a large-scale breeding and release program was organized at Patuxent, Maryland, which housed one of the largest captive breeding colonies of eagles. The Patuxent release program ended in 1988.
However, individual states still continue with small-scale programs, such as the one at the Philadelphia Zoo. The bald eagle is still listed as endangered in Pennsylvania. Once at a low point of only 3 pairs, the population grew to 43 pairs by 1999. The Philadelphia Zoo's bald eagle breeding and release program began in 1995 with the first hatchings at the Zoo in its 100-year history of exhibiting eagles. The two eggs were hatched, and the chicks were soon released in Massachusetts by wildlife biologists. The Zoo continued its work in 1996 when two chicks were placed in nests in Pennsylvania. Both chicks successfully fledged and dispersed.
Fun Facts
Bald eagles construct the largest nest of all North American birds. Eagles are known to reuse nests for many years, both by same individuals as well as different individuals.
Bald eagles are able to tuck their wings and dive from above at incredible speeds. Some eagles can approach around 200 miles per hour in an attack on prey.
Eagles travel by soaring and gliding on thermals and can cover great distances without flapping their wings.
Bald eagles are fish eagles. They have spiny pads on the undersides of their talons to help keep wet, wriggling prey in place.
Conservation
Introductions
Animal Lingo
Want More?
Sources:
(1) del Hoya, A.J., Elliot, A. and Sargatal, J. eds. 1994. Handbook of the Birds of the World. Vol. 2 New World Vultures to Guineafowl. Barcelona: Lynx Edicions.
(2) Gerrard, J.M. and Bortolotti, G.R. 1988. The Bald Eagle: Haunts and Habits of a Wilderness Monarch. Washington, DC: Smithsonian Institute Press.
(3) Grier, J.W. 1982. Ban of DDT and Subsequent Recovery of Reproduction in Bald Eagles. Science 218: 1232?1235.
(4) Kjos, C.G. 1992. Bald Eagle Numbers Continue to Rise. US Fish and Wildlife Service Endangered Species Technical Bulletin 17: 3?4.
(5) Ehrlich, P.R., Dobkin, D.S. and Wheye, D. 1992. Birds in Jeopardy. Stanford, CA: Stanford University Press.
|