NAME: Bald Eagle or American Eagle (Haliaeetus leucocephalus)
U.S.A.'S NATIONAL EMBLEM: The Bald
Eagle was officially declared the National Emblem of the United States
by the Second Continental Congress in 1782. It was selected by the U.S.A.'s
founding fathers because it is a species unique to North America. Ben
Franklin wanted the wild turkey to be the national bird, because he thought
the eagle was of bad moral character. The Bald Eagle has since become
the living symbol of the U.S.A.'s freedoms, spirit and pursuit of excellence.
Its image and symbolism have played a significant role in American art,
folklore, music and architecture.
COLOR & SIZE: The feathers of newly
hatched Bald Eaglets are light grey, and turn dark brown before they
leave the nest at about 12 weeks of age. During their third and fourth
years, Bald Eagles have mottled brown and white feathers under their
wings and on their head, tail and breast. The distinctive white head
and tail feathers do not appear until Bald Eagles are about 4 to 5 years
old. Their beak and eyes turn yellow during the fourth and fifth year,
and are dark brown prior to that time. Bald Eagles are about 29 to 42
inches long, can weigh 7 to 15 pounds, and have a wing span of 6 to 8
feet. This makes them one of the largest birds in North America. Females
are larger than males. Bald Eagles residing in the northern U. S. are
larger than those that reside in the south. They have a life span of
up to 40 years in the wild, and longer in captivity.
Listen to the voice of an eagle. (Quicktime) The American Bald Eagle has a high-pitched, shrill, and staccato whistle-like voice. The eagle does not have vocal chords. Instead, the sound is made in the “syrinx”, which is where the windpipe divides to go to the lungs. The bird’s call is used to either reinforce the bond between mated eagles or to warn other predators from coming close to their nest and/or into a territory they will defend. The Bald Eagle has a high yet interesting voice.
HABITAT & RANGE: Bald Eagles live
near large bodies of open water such as lakes, marshes, seacoasts and
rivers, where there are plenty of fish to eat and tall trees for nesting
and roosting. Bald Eagles have a presence in every U. S. state except
Hawaii. Bald Eagles use a specific territory for nesting, winter feeding
or a year-round residence. Its natural domain is from Alaska to Baja,
California, and from Maine to Florida. Bald Eagles that reside in the
northern U. S. and Canada migrate to the warmer southern climates of the
U. S. during the winter to obtain easier access to food, especially fish.
Some Bald Eagles that reside in the southern U. S. migrate slightly north
during the hot summer months.
FOOD SOURCE & FLIGHT: Bald Eagles
feed primarily on fish, but also eat small animals (ducks, coots, muskrats,
turtles, rabbits, snakes, etc.) and occasional carrion (dead animals).
They swoop down to seize fish in their powerful, long and sharp talons
(approximately 1,000 pounds of pressure per square inch in each foot).
They can carry their food off in flight, but can only lift about half
their weight. Bald Eagles have been recorded at 44 miles per hour in
level flight. They seldom dive vertically on their prey, preferring to
decend more gradually and snatch fish, rabbits, etc. with their feet. Their
diving speed is estimated at 75 to 100 miles per hour. They
can fly to altitudes of 10,000 feet or more, and can soar aloft for hours
using natural wind currents and thermal updrafts. Bald Eagles can swim
to shore with a heavy fish using their strong wings as paddles. However,
it is also possible that they can drown if the fish weighs too much.
NESTING & BREEDING: Bald Eagles are monogamous and mate for life. A Bald Eagle will only select
another mate if its faithful companion should die. They build large nests,
called eyries, at the top of sturdy tall trees. The nests become larger
as the eagles return to breed and add new nesting materials year after year.
Bald Eagles make their new nests an average of 2 feet deep and 5 feet across.
Eventually, some nests reach sizes of more than 10 feet wide and can weigh
several tons. When a nest is destroyed by natural causes it is often rebuilt
nearby. Nests are lined with twigs, soft mosses, grasses and feathers. The
female lays 1 to 3 eggs annually in the springtime, which hatch after about
35 days of incubation. Hunting, egg incubation, nest watch, eaglet feeding
and eaglet brooding duties are shared by both parents until the young are
strong enough to fly at about 12 weeks of age. Eaglets are full size at
12 weeks of age. Only about 50% of eaglets hatched survive the first year.
POPULATION SIZE & DECLINE: Bald Eagles
were once very common throughout most of the United States. Their population
numbers have been estimated at 300,000 to 500,000 birds in the early 1700s.
Their population fell to threatened levels in the continental U.S. of less
than 10,000 nesting pairs by the 1950s, and to endangered levels of less
than 500 pairs by the early 1960s. This population decline was caused by
humans. The mass shooting of eagles, use of pesticides on crops, destruction
of habitat, and contamination of waterways and food sources by a wide range
of poisons and pollutants all played a role in harming the Bald Eagle's
livelihood and diminishing their numbers. For many years the use of DDT
pesticide on crops caused thinning of eagle egg shells, which often broke
RECOVERY & PROTECTION: Strong
endangered species and environmental protection laws, as well as active
private, state and federal conservation efforts, have brought back the
U.S.A.'s Bald Eagle population from the edge of extinction. The use of
DDT pesticide was outlawed in the U.S. in 1972
and in Canada in 1973. This action has contributed greatly
to the return of the Bald Eagle to America's skies.
The Bald Eagle
was listed as Endangered in most of the U.S. from 1967 to 1995,
when it was slighted upgraded to Threatened in the lower 48 states.
The number of nesting pairs of Bald Eagles in the lower 48 states had
increased from less than 500 in the early 1960's to over 10,000
in 2007. They had recovered sufficiently to delist
them from Threatened status on June 28, 2007.
the primary law protecting Bald Eagles has shifted from the
Endangered Species Act to the Bald and Golden Eagle Act. Although Bald
Eagles have made an encouraging comeback throughout the U.S.A.
since the early 60s, they continue to be face hazards that must be
closely monitored and controlled. Even though illegal, Bald Eagles
are still harassed, injured and killed by guns, traps, power lines,
windmills, poisons, contaminants and destruction of habitat.
there is much less funding to provide for their needed management
and protection. Public awareness about their status, strict enforcement
of protective laws, preservation of their habitat, and support for
environmental conservation programs are needed to assure a healthy
and secure future for the U.S.A.'s majestic and symbolic national bird.