U.S. Fish & Wildlife Service
Bald Eagle
Haliaeetus leucocephalus
A North American species with a
historic range from Alaska and Canada
to northern Mexico, the bald eagle is an
Endangered Species Act success story.
Forty years ago, our national symbol
was in danger of extinction throughout
most of its range. Habitat destruction
and degradation, illegal shooting,and
the contamination of its food source,
largely as a consequence of DDT,
decimated the eagle population.
The federal government’s banning of
DDT and related pesticides, habitat
protection afforded by the Endangered
Species Act, and conservation actions
taken by the American public have
helped bald eagles make a remarkable
recovery.
Bald Eagle Biology
Distinguished in the adult plumage by
a white head and white tail, bald eagles
are powerful, brown birds that may
weigh 14 pounds and have a wingspan
of 8 feet. Male eagles are smaller,
weighing as much as 10 pounds and
have a wingspan of 6 feet. Sometimes
confused with golden eagles, bald
eagles are mostly dark brown until they
are four to five years old and acquire
their characteristic coloring. There is
a distinction between the two species,
though, even during the early years.
Only the tops of the bald eagle’s legs
have feathers. The legs of golden eagles
are feathered all the way down.
Bald eagles live near rivers, lakes, and
marshes where they can find fish, their
staple food. As their populations grow,
however, bald eagles are expanding
their range, even nesting in urban
areas. Bald eagles will also feed on
waterfowl, turtles, rabbits, snakes, and
other small animals and carrion.
Bald eagles require a good food base,
perching areas, and nesting sites. Their
habitat includes estuaries, large lakes,
reservoirs, rivers, and some seacoasts.
In winter, the birds congregate near
open water in tall trees for spotting
prey and night roosts for sheltering.
Bald eagles usually choose the tops of
large trees to build nests, which they
typically use and enlarge each year.
However, nests have also been found on
cliffs, the ground, and even on human-
made structures like cell phone towers.
Nests may reach 10 feet across and
weigh a half ton. Bald eagles may
also have one or more alternate nests
within their breeding territory. The
birds travel great distances but usually
return to breeding grounds within 100
miles of the place where they were
raised. Bald eagles may live 15 to 25
years in the wild, longer in captivity.
Breeding bald eagles typically lay one
to three eggs once a year, and they
hatch after about 35 days. The young
eagles are flying within three months
and are on their own about a month
later. However, disease, lack of food,
bad weather, or human interference can
kill many eaglets. Recent studies show
that approximately 70 percent survive
their first year of life.
The Plight of the Bald Eagle
When America adopted the bald
eagle as the national symbol in 1782,
anecdotal accounts stated the country
may have had as many as 100,000
nesting eagles. The first major decline
of the species probably began in the
mid to late 1800’s, coinciding with the
decline of waterfowl, shorebirds, and
other prey.
Although they primarily eat fish
and carrion, bald eagles used to be
considered marauders that preyed on
chickens, lambs, and domestic livestock.
Consequently, the large raptors
were shot in an effort to eliminate a
perceived threat. Coupled with the
loss of nesting habitat, bald eagle
populations declined.
In 1940, noting that the species was
“threatened with extinction,” Congress
passed the Bald Eagle Protection
Act, which prohibited killing, selling,
or possessing the species. A 1962
amendment added the golden eagle,
and the law became the Bald and
Golden Eagle Protection Act.
Shortly after World War II, DDT was
hailed as a new pesticide to control
mosquitoes and other insects. However,
DDT and its residues washed into
nearby waterways, where aquatic
plants and fish absorbed it. Bald eagles,
in turn, were poisoned with DDT when
they ate the contaminated fish. The
chemical interfered with the ability of
the birds to produce strong eggshells.
Jim Hudgins/USFWS
U.S.
Fish & Wildlife Service
Migratory Bird Program
5275 Leesburg Pike, MS: MB
Falls Church, VA 22041
703/358-1714
www.fws.gov/birds/
Febuary 2021
As a result, their eggs had shells so
thin that they often broke during
incubation or otherwise failed to hatch.
DDT also affected other species such as
peregrine falcons and brown pelicans.
Some other pesticides related to DDT
are suspected to have caused increased
mortality, in addition to the harmful
effects on reproduction.
By 1963, with only 417 nesting pairs of
bald eagles known to exist, the species
was in danger of extinction.
The Road Back
As the dangers of DDT became known,
in large part due to the 1962 publication
of Rachel Carson’s book Silent Spring,
the Environmental Protection Agency
took the historic and, at the time,
controversial step of banning the use
of DDT and some related pesticides in
the United States. That was in 1972,
and it was the first step on the road to
recovery for the bald eagle.
In 1967, the Secretary of Interior
listed bald eagles south of the 40th
parallel under the Endangered Species
Preservation Act of 1966. Following
enactment of the Endangered
Species Act of 1973, the Service listed
the species in 1978 as endangered
throughout the lower 48 states, except
in Michigan, Minnesota, Oregon,
Washington, and Wisconsin where it
was designated as threatened.
The species was not listed as
threatened or endangered in Hawaii
because it does not occur there, or in
Alaska because populations there have
remained robust.
Listing the species as endangered
provided the springboard for the
Service and its partners to accelerate
the pace of recovery through captive
breeding programs, reintroduction
efforts, law enforcement, and nest site
protection during the breeding season.
Population Milestones
In July 1995, the Service announced
that bald eagles in the lower 48 states
had recovered to the point where those
populations previously considered
endangered could be reclassified to the
less critical category of threatened.
Then in 2007, the Service estimated
there were at least 9,789 nesting
pairs of bald eagles in the contiguous
United States. Bald eagles staged a
remarkable population rebound and
recovered to the point that they no
longer needed the protection of the
Endangered Species Act. Thus, on June
28, 2007, the Service announced the
recovery of our nation’s symbol and
removal from the list of threatened and
endangered species.
Continued Population Growth
In 2016, the Service published the bald
eagle population status report as part
of a Programmatic Environmental
Impact Statement. In that report which
analyzed data from 2009, the bald eagle
population in the lower 48 status was
estimated to be 72,434 individuals,
including 30,548 breeding pairs.
Then in 2021, the Service published
a technical update that provided the
newest estimates for the bald eagle
population in the lower 48 states for
the period 2018-2019, totaling 316,700
individuals, which included 71,467
breeding pairs.
What Lies Ahead
The recovery of the bald eagle is one
of the most well-known conservation
success stories of all time. The Service
continues to work with our partners in
state and federal agencies, tribes, non-
government organizations and private
landowners to ensure that our nation’s
symbol flourishes.
Although the Service removed the
bald
eagle from the list of threatened
and endangered species under the
Endangered Species Act, the bird
continues to be protected by the
Migratory Bird Treaty Act and the
Bald and Golden Eagle Protection Act.
Both laws prohibit killing, selling or
otherwise harming eagles, their nests,
or eggs.
The Service developed guidelines
to help landowners avoid disturbing
eagles and encourage beneficial
conservation practices.
For more information on the recovery
of bald eagles, please visit https://
www.fws.gov/birds/management/
managed-species/eagle-management.php
Tom Koerner/USFWS
