|
The Bald Eagle (Haliaeetus leucocephalus) is
a bird of prey originating in North America, most
recognizable as the national bird of the United
States. The species was on the brink of extinction
late in the 20th century but now has a stable
population and is in the process of being removed
from the U.S. federal government's list of endangered
species.
The bird gets both its common and scientific
names from the distinctive appearance of the adult's
head. Bald in the English name refers to the white
head feathers, and the scientific name is derived
from Haliaeetus, the New Latin for "sea eagle,"
(from the Greek haliaetos) and leucocephalus,
the Greek for "white head," from leukos
("white") and kephale ("head").
Range and habitat
Bald Eagles can be found in small concentrations
throughout the U.S. and Canada, particularly near
large bodies of water. The state with the largest
resident population is Alaska; out of the estimated
100,000 Bald Eagles on Earth, half live in Alaska.
Description
An immature bird has speckled brown feathers all
over, the distinctive head and body plumage arriving
2–3 years later, before sexual maturity.
Adult females have a wingspan of approximately
2.1 meters (7 feet); adult males have a wingspan
of 2 meters (6 feet, 6 inches). Adult females
weigh approximately 5.8 kg (12.8 lb), males weigh
4.1 kg (9 lb).
Bald Eagles are protected by two federal laws
in the United States: the Eagle Law, which protects
Bald and Golden Eagles, and the Migratory Bird
Act.
Behavior
Bald Eagles build huge nest platforms out of branches,
usually in large trees. Pairs, who mate for life,
add material to the nest each breeding season.
After several years, the nest may weigh upwards
of a thousand pounds or more.
Bald Eagles which are old enough to nest often
return to the area in which they were raised.
They are more social than many other raptor species:
an adult bald eagle looking for a nesting site
is more likely to select a location that contains
other immature eagles than one with no eagle population.
Bald Eagles are powerful fliers, and ride thermal
convection currents to range far.
They have a long lifespan, with reports of birds
in captivity living to be 60 years old.
They do not scream as often shown on television.
Usually the call of a red-tailed hawk is placed
over the image of a flying eagle. They squeak
and have a shrill cry, punctuated by grunts.
Reproduction
Bald Eagles are sexually mature at 4 or 5 years
of age. Mated pairs produce between one and three
eggs per year, but it is rare for all three chicks
to successfully fledge. Third chicks are sometimes
removed from nests to use in reintroduction programs
in areas where the species has died out.
In such programs, the birds are raised in boxes,
on platforms in the tree canopy, and fed in such
a way that they cannot see the person supplying
their food, until they are old enough to fly and
find their own food.
Diet
The Bald Eagle's diet is varied, including carrion,
fish, smaller birds, rodents, and sometimes food
scavenged or stolen from campsites and picnics.
To hunt, the eagle swoops down over the water
and snatches the fish out of the water with its
talons. They eat by holding the fish in one claw
and tearing the flesh with the other. Eagles have
structures on their toes called spiricules that
allow them to grasp fish. Osprey also have this
adaptation.
Sometimes, if the fish is too heavy, the eagle
will be dragged into the water. It may swim to
safety, but some eagles drown or succumb to hypothermia.
Eagles and humans
As the symbol of the United States the bald eagle
is sought after in captivity. As a rule they are
poor birds for public shows being timid and prone
to becoming highly stressed.
Due to their immense strength and unpredictable
nature bald eagles should only be kept by very
competently trained individuals who have all the
proper permits.
Rare vagrant
This species has occurred as a vagrant once in
Ireland. The exhausted specimen was discovered
by a national parks worker in a northern heath.
Presumably, a storm blew it out to sea, and the
bird struggled across the Atlantic Ocean.
National Bird of the US
The Bald Eagle is the national bird of the United
States of America. Its national significance dates
back to June 20, 1782, when the Continental Congress
officially adopted the current design for the
Great Seal of the United States including a bald
eagle grasping arrows and an olive branch with
its talons. Some states had earlier adopted the
bird as a symbol; for example New York State did
so in 1778.
In 1784, after the end of the Revolutionary War,
Benjamin Franklin wrote a famous letter to his
daughter from Paris criticizing the choice and
suggesting the Wild Turkey as an alternative:
For my own part I wish the Bald Eagle had not
been chosen the Representative of our Country.
He is a Bird of bad moral character. He does not
get his Living honestly. You may have seen him
perched on some dead Tree near the River, where,
too lazy to fish for himself, he watches the Labour
of the Fishing Hawk; and when that diligent Bird
has at length taken a Fish, and is bearing it
to his Nest for the Support of his Mate and young
Ones, the Bald Eagle pursues him and takes it
from him.
With all this Injustice, he is never in good Case
but like those among Men who live by Sharping
& Robbing he is generally poor and often very
lousy. Besides he is a rank Coward: The little
King Bird not bigger than a Sparrow attacks him
boldly and drives him out of the District. He
is therefore by no means a proper Emblem for the
brave and honest Cincinnati of America who have
driven all the King birds from our Country . .
.
I am on this account not displeased that the Figure
is not known as a Bald Eagle, but looks more like
a Turkey. For the Truth the Turkey is in Comparison
a much more respectable Bird, and withal a true
original Native of America . . . He is besides,
though a little vain & silly, a Bird of Courage,
and would not hesitate to attack a Grenadier of
the British Guards who should presume to invade
his Farm Yard with a red Coat on.
Despite Franklin's objections the Bald Eagle remained
the emblem of the United States. Today it appears
on many official seals in addition to the back
of 25 cent coin.
The text within
the green border is licensed under the GNU
Free Documentation License. To see the full
article with more information, visit the Wikipedia
article "Bald
Eagle". All content outside the green border
is copyrighted by McBryde
Website Design.
|