Bald Eagle Haliaetus
leucocephalus
Description
The bald eagle is one of the
most easily recognized birds in North America,
with its bright white head and tail. The term
"bald" does not refer to the eagle
appearing "hairless," the word actually
once meant "white," and both sexes
sport the characteristic white head. Feet and
bill are yellow in both sexes.
Juvenile
bald eagles lack the characteristic white head
and tail feathers, which do not appear until
about five years of age. Until then the only way
to distinguish a juvenile bald eagle from a golden eagle is to look at the legs, which are bare
in bald eagles and fully feathered in golden
eagles.
Females are 35-37 inches long,
have a wingspan of 79-90 inches, and weigh about
14 pounds; males are 30-34 inches long, have a
wingspan of 72-85 inches, and weigh about 10
pounds.
Like all other birds of prey,
the bald eagle has excellent eyesight. It also
has good color vision, and can see both forward
and to the side at the same time. It is capable
of flying up to 35 miles per hour, to an altitude
of 10,000 feet, and often takes advantage of
thermals when travelling long distances.
Distribution and
Habitat
Bald eagles are most commonly
seen in Alaska, Canada, and around the Gulf of
Mexico, with flocks often appearing in other
regions of the continental United States on a
seasonal basis. Northern populations often
migrate southward as rivers and lakes freeze over
in their native habitats, but do so in response
to moving food supplies rather than because of
cold weather. In both native and migratory
habitats the bald eagle is almost always found
near the coast, or along a large lake or major
river that remains ice-free.
Diet
Bald eagles feed primarily on
fish, but will also take a variety of small
mammals, waterfowl, and carrion. They exhibit a
wide variety of fishing and hunting habits,
ranging from taking prey while flying overhead to
simply pouncing from ambush. Bald eagles are also
notorious for stealing food from other birds,
especially ospreys and fellow bald eagles. They
can open and close their powerful, sharp talons
at will, and are capable of lifting up to four
pounds.
Reproduction
Bald
eagles mate for life, but if one mate dies the
other will seek a new one. They return to the
same nest year after year, making repairs and
additions as needed. If the nest is destroyed the
pair will build a new one; if possible it will
use the same tree or rocky cliff, but if not it
will build as close to the original site as
possible, even if humans have encroached on the
area. The nest itself is made of sticks up to six
feet long, usually lined with weeds, stubble and
earth. A new nest may be up to five feet in
diameter, while older nests have been known to
reach a diameter of nine feet and more. High
trees are preferred, but bald eagles will also
nest on high rocky cliffs or pinnacles, and will
also take advantage of special nesting platforms
provided for them by humans.
Breeding season runs from
January through March in the north, September
through November in the south. Two or three white
or pale blue eggs, each about 2-3/4 inches long,
are laid five to ten days after mating, generally
a day or two apart. The eggs are incubated by
both parents for about 35 days. Chicks
are snowy white in color, very weak, and have
limited vision, but mature fairly rapidly.
Although the parents will feed all chicks in the
nest, the oldest one will typically bully its
nestmate(s) until it has the nest to itself. The
parents will continue caring for the remaining
chick until it is fully fledged, at about 15-20
weeks of age, and will then chase it away. The
parents will teach the chick how to fly, but will
not teach it how to hunt, that is something the
youngster must learn on its own.
Bald eagles become sexually
mature at about five years, and can live up to 30
years in the wild.
Conservation Status
Once threatened throughout
North America due to habitat destruction and the
use of pesticides and other chemicals (which
damaged the eggs and entered adults via their
food), the bald eagle was officially taken off
the Endangered Species List on June 28, 2007. It
is still protected under the Migratory Bird
Treaty Act and the Bald and Golden Eagle
Protection Act, however. The bald eagle has been
the national bird of the United States since
1782.
Scientific
Classification
phylum Chordata
subphylum Vertebrata
class Aves
order Falconiformes
family Accipitridae
subfamily Accipitrinae
genus & species Haliaetus leucocephalus
American Bald Eagle Information www.baldeagleinfo.com
Golden Eagle
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