Bald
Eagle Haliaeetus leucocephalus
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STATUS:
Reclassified as threatened (60 FR 36000- July 12, 1995). Originally listed as endangered (32 FR
4001-March 11, 1967; 43 FR 6233-February 14, 1978) without critical habitat in
all but five of the contiguous 48 states (listed as threatened in Washington,
Oregon, Minnesota, Wisconsin, and Michigan).
DESCRIPTION: Large hawk-like bird with 6-7 feet wingspan
and unfeathered feet.
Adult has white head, neck, and tail.
While gliding or soaring it keeps wings flat, not uplifted like
vultures. Immatures
are mostly dark, and may be confused with immature golden eagles. However, golden eagles have a more sharply
defined white pattern on underside of wings and tail.
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HABITAT: In Texas, preferred nesting habitat is along
river systems, or within 1-2 miles of some other large body of water, such as a
lake or reservoir. Nests are often located in areas where forest, marsh, and
water meet. Large, tall (40-120 ft.) trees are used for nesting and roosting
(taller than the general forest canopy, providing an unobstructed flight path
to nest). Tree species used for nesting in Texas include loblolly pine, bald
cypress, oak, cottonwood, and sycamore. Nearby (within 0.5 miles) wetland areas
are necessary for feeding. Fish is generally the primary food, but eagles in
Texas also prey on waterfowl, turtles, small mammals, and carrion.
DISTRIBUTION:
Present:
Nesting populations are gradually increasing in Texas, with territories located
primarily along rivers, near reservoirs, and along the Gulf Coast. Wintering
eagles may occur statewide on rivers, streams, reservoirs and other areas of
open water where fish, waterfowl,and
carrion are available for food. See Bald Eagle Wintering Areas in Texas on the
following page.
Historic:
Found throughout the contiguous United States, Canada, and northern Mexico.
THREATS
AND REASONS FOR DECLINE: Past threats include reproductive
failure caused by pesticides, loss of riparian habitat, and unrestricted
killing by humans (including shooting, poisoning, and trapping). Current
threats are habitat loss, human encroachment on nesting sites, and lead
poisoning (even low levels can cause neurological dysfunction, behavioral
abnormalities, anemia, and increased susceptibility to disease).
OTHER
INFORMATION: In Texas, bald eagle nesting typically occurs
from October to July. Clutch size varies from 1 to 3,
dull white eggs are incubated for approximately 35 days. Young generally fledge
in April, after 10-12 weeks of growth, but parental care continues for another
4-6 weeks. Northern migration begins in
May; occasionally, a pair will remain within a territory year-round. Wintering
Bald eagles may arrive in north Texas as early as October and return north
February through March. Bald eagles are particularly vulnerable to disturbance
during the nesting period. Bald eagles
are protected by the Endangered Species Act, Bald Eagle Protection Act and
Migratory Bird Treaty Act.
REFERENCES:
Lish, J.W.
1975. Status and Ecology of Bald
Eagles and Nesting Golden Eagles in Oklahoma.
Unpubl. Thesis, Oklahoma State University,
Stillwater, Oklahoma.
Texas Parks and Wildlife Department. 1993.
Job No. 30: Bald eagle nest survey and management. Performance report, Federal
Aid Project No. W-125-R-4. TPWD, Austin, TX.
Texas Parks and Wildlife Department. 1993.
Job No. 59: Bald eagle post-fledging survival and dispersal. Final report, Federal Aid
Project No. W-125-R-4. TPWD, Austin, TX.
U.S.
Fish and Wildlife Service (USFWS).
1983. Northern States Bald Eagle
Recovery Plan. USFWS, Endangered Species Office, Twin Cities, MN.
------. 1989.
Southeastern States Bald Eagle Recovery Plan. USFWS, Endangered Species
Office, Atlanta, GA.
