Common Name: Bald Eagle
Bald Eagle is a member of the Accipitridae Family, under the Order Accipitriformes, meaning that it is a diurnal
bird of prey. Its name is derived from “Haliaeetus,” meaning “sea
eagle,” and “leucocephalus,” meaning “white head.” The common name,
“Bald Eagle” comes from the English word “piebald,” which usually
refers to a black and white pattern referring to the Bald Eagle’s
white head and tail. Immature Eagles do not reach adult coloration
until around five years old. Until that time they are a molted brown
Photos: Ivan Andrijevic &
Bald Eagles have a body length of
around 27-40 in (68 to 100 cm). Females are 25% larger, showing a
clear example of sexual dimorphism. The female wingspan is 7 ft
(2.1 m), while the male wingspan is 6 ft 6 in (2 m). The average
weight of a female is 12.9 lbs (5.8 kg) and the male weighs 9 lbs
(4.1 kg). In the wild Bald Eagles typically live 20 to 30 years, but
they have been known to live up to 50 years. Bald Eagles that live
in captivity typically live up to 60 years.
Bald Eagles are usually found in
habitats that provide plenty of warm-water fishes. These areas
include seacoasts, rivers, and large lakes. They seem to prefer water
bodies with a circumference of at least 7 mi (11 km).
Their diet consists mostly of
fish, but they also eat other birds such as grebes, ducks, geese and
mammals such as rabbits, raccoons, muskrats, and even deer fawn.
Bald Eagles also rely on carrion and will often live off of
carcasses throughout the winter.
Bald Eagles display the same
behaviors as other birds including preening and brooding. They are
not known to be aggressive birds, but when a confrontation occurs,
it is usually fatal. Bald Eagles will also steal prey from other
birds of prey, such as Ospreys, who often share habitats with Bald
Eagles. Many believe that Bald Eagles mate for life, however, if
one member dies, they will be replaced.
For courtship, Bald Eagles display
a “cartwheel” where they lock talons and freefall until right before
hitting the ground. Bald Eagles return to the same nest each
year and these nests can reach 8 feet across, weigh a ton, and
usually are found in trees. However, if no trees can be found, they
have been known to nest on the ground. Each year, the eagles lay
one to three eggs and both the male and female take turns brooding.
Incubation lasts 35 days and the fledglings are cared for for 8 to
Photo: M. Noonan
WHERE TO FIND THEM
Although Bald Eagles were declared and Endangered Species in 1967,
due to conservation and knowledge, their population has made a
comeback and on June 28, 2007, the Department of Interior took the
Bald Eagle off of the Endangered Species list. They are still
protected by the Migratory Bird Treaty Act and Bald and Golden Eagle