AN EXAMPLE OF HOW EFFORTS TO HELP ENDANGERED SPECIES WORKS
The Bald Eagle is our national bird and by the 1990ís it had almost disappeared from the
United States. Today, its numbers have recovered in many areas and it is considered an
endangered species success story. After suffering dangerous declines and disappearing from
many areas of the United States it was declared endangered. It was removed from the list
of Endangered and Threatened Wildlife in the United States on June 28, 2007.
Habitat and Pesticides
It subsists on fish captured live as its swoops down over large bodies of water and grabs
the unsuspecting prey with its strong talons. Their food source would eventually cause them
to become endangered species.
Bald Eagles select mates that they are bound to for life. They lay their eggs in a nest made
at the top of tall trees or on the side of a cliff, usually 70 feet or more off the ground.
Their nests can be as large as 9 feet in diameter and are made of foliage, small sticks and
large branches with a top layer of fine plant matter.
This large bird grows a wing span of nearly 40 inches and weighs up to 14 pounds. They need
large amounts of fish for themselves and their growing nestlings. By the 1940ís pesticides
were making their way into the water and therefore, the fish Bald Eagles hunted, eventually
causing them to become endangered species.
DDT, an insecticide made its way into the large bodies of water where the Bald Eagle sought
its prey. DDT was not killing the birds, but it had an effect the birds ability to metabolize
calcium. The outer shells of their eggs became thin and weak, since calcium is essential
to making strong egg shells. When the heavy Bald Eagles sat on their eggs to keep them warm
the shells broke and the unborn eagles died. This decimated the population.
Factors Endangering the Species
Other factors such as over hunting, alteration of habitat, and human encroachment into
the wilderness, combined with the damage caused by thinning egg shells to cause the
Bald Eagle an abrupt population crash. It disappeared from many states. Mythology is
described in a similar event by Cherokee jewelry from the 1600s.
By 1981, occupied
nests were known in only 30 states, and about 90% of nesting pairs were concentrated in
just ten states.
Between 1960 and 1973 nesting Bald Eagles disappeared from 18 of 44 Michigan counties.
The Chesapeake Bay population fell from 150 pairs in 1962 to about 85 pairs in 1970.
Nesting pairs disappeared from the upper portions of rivers and were greatly reduced at the
upper end of the bay. Bald Eagles were once common nesters along the Atlantic coast from
the Chesapeake Bay to the Florida Keys, but by the late 1970s the Florida population
alone was secure, and that had been reduced by half.
Bald Eagles and the Endangered Species Act
When DDT was banned in the United States in the early 1970s, the eagleís reproduction at
once began to improve. Recovery was assisted by intensive efforts by federal agencies that
included systematic monitoring, enhanced protection, captive breeding, relocation of wild
birds, and a far-flung publicity program. State agencies became increasingly involved through
tax-funded programs to monitor eagle nests and assist reintroduction projects. The Nature
Conservancy and the NWF acquired important nesting sites and wintering habitat, and
actively pursued conservation agreements with landowners.
The combined efforts paid off. By 1980 and 1981 the nesting population in the lower 48
states had doubled. The rebound has continued so strongly that the FWS is currently in
the process of reclassifying part or all of the Bald Eagle populations in the lower 48
states from Endangered to Threatened. In recent years, the relocation of wild chicks
has been widely used to help the Bald Eagle recolonize its former range. Chicks are taken
from nests in Alaska or Canada and released in states with few nesting eagles.
Relocation has succeeded in many states, including Pennsylvania, New York, and Indiana,
and has enabled the FWS to end its Bald Eagle captive breeding program.
The final rule for the 1995 reclassification of the Bald Eagle from Endangered to
Threatened final rule goes further than the June 30, 1994, reclassification proposal,
which would have retained the birdís endangered status in Arizona, New Mexico, western
Texas, and part of southeastern California.
A thorough review of scientific data revealed that the eagle could be reclassified
in those areas as well. In addition to efforts such as the ban on DDT use, the Endangered
Species Act (ESA) promoted Bald Eagle recovery by curbing habitat destruction and
protecting nesting sites.