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Eagle Nature Foundation
American Bald Eagle
The eagle had represented power and majesty for thousands of years before
John Adams, Thomas Jefferson, and our Nation’s other founding fathers chose
the bald eagle as our national symbol in 1782. Then as now, the eagle
represented “a free spirit, high soaring and courageous.” Moreover, the bald
eagle has always been uniquely American, found only on our continent.
At the time the Republic was formed, the bald eagle was common in North
America, soaring through the skies over its timber-bordered lakes, streams, and
coastlines. Perhaps as many as 25,000 lived in what we now call the lower 48
states.
Today, except for the Southwestern bald eagles the bald eagle has been removed
from the “Threatened Species List “in the United States. ” Its number dropped
dangerously low over the last century, for a number of reasons. However, the
outlook is getting better. Because of the efforts of many people, the decline in the
bald eagle population had apparently been halted and perhaps, was even
reversed for a few years, but is now on the decline once more.
Conservationists view recent improvements with cautious optimism. But much
work remains to be done - increased preservation of crucial natural habitat,
greater public awareness of the eagle’s problems, plus more public and private
funding for conservation and research.
A major part of this effort lies in informing Americans about our National Symbol.
A greater understanding and appreciation of this majestic, threatened bird will
help it to survive and flourish as a valued part of our heritage.
Symbol Adopted
On June 20, 1782, the bald eagle was formally adopted as the emblem of the
United States, a living symbol of our nation’s strength and freedom. Today, the
bald eagle represents more than a nation. The eagle typifies the plight of all
wildlife struggling to survive in a world dominated by the needs of human beings.
The decline of the bald eagle reflects the reduced quality of our natural
environment. If this powerful symbol of freedom continues to be abused and
neglected as it has been for decades, what hope does the future hold for less
recognized species?
Concern for the fate of all endangered species is growing. At the same time,
environment. Clear thought and keen awareness of these issues are essential, if
we are to preserve unique and important ecosystems.
What is the Bald Eagle?
The bald eagle is a bird of prey - that is, a flesh - eating bird. Its Latin name -
Haleaeetus leucocephalus - means “white-headed sea eagle.” It is called “bald”
because the word was used in times past to mean white or white faced.
John Adams, Thomas Jefferson, and our Nation’s other founding fathers chose
the bald eagle as our national symbol in 1782. Then as now, the eagle
represented “a free spirit, high soaring and courageous.” Moreover, the bald
eagle has always been uniquely American, found only on our continent.
At the time the Republic was formed, the bald eagle was common in North
America, soaring through the skies over its timber-bordered lakes, streams, and
coastlines. Perhaps as many as 25,000 lived in what we now call the lower 48
states.
Today, except for the Southwestern bald eagles the bald eagle has been removed
from the “Threatened Species List “in the United States. ” Its number dropped
dangerously low over the last century, for a number of reasons. However, the
outlook is getting better. Because of the efforts of many people, the decline in the
bald eagle population had apparently been halted and perhaps, was even
reversed for a few years, but is now on the decline once more.
Conservationists view recent improvements with cautious optimism. But much
work remains to be done - increased preservation of crucial natural habitat,
greater public awareness of the eagle’s problems, plus more public and private
funding for conservation and research.
A major part of this effort lies in informing Americans about our National Symbol.
A greater understanding and appreciation of this majestic, threatened bird will
help it to survive and flourish as a valued part of our heritage.
Symbol Adopted
On June 20, 1782, the bald eagle was formally adopted as the emblem of the
United States, a living symbol of our nation’s strength and freedom. Today, the
bald eagle represents more than a nation. The eagle typifies the plight of all
wildlife struggling to survive in a world dominated by the needs of human beings.
The decline of the bald eagle reflects the reduced quality of our natural
environment. If this powerful symbol of freedom continues to be abused and
neglected as it has been for decades, what hope does the future hold for less
recognized species?
Concern for the fate of all endangered species is growing. At the same time,
environment. Clear thought and keen awareness of these issues are essential, if
we are to preserve unique and important ecosystems.
What is the Bald Eagle?
The bald eagle is a bird of prey - that is, a flesh - eating bird. Its Latin name -
Haleaeetus leucocephalus - means “white-headed sea eagle.” It is called “bald”
because the word was used in times past to mean white or white faced.
Field Marks:
Adult: dark brown body, white head and tail, yellow feet, beak and eyes.
Immature: normally dark brown body, showing white in the wing linings and
breast. It has brown head, tail, feet, beak and eyes and is similar in appearance
to the Golden Eagle without white on the tail. Golden Eagles have feathered legs
to the toes. Bald eagles have bare legs.
Adult: dark brown body, white head and tail, yellow feet, beak and eyes.
Immature: normally dark brown body, showing white in the wing linings and
breast. It has brown head, tail, feet, beak and eyes and is similar in appearance
to the Golden Eagle without white on the tail. Golden Eagles have feathered legs
to the toes. Bald eagles have bare legs.
Some immatures may have a white breast, a brown breast or a mottled breast.
A 4 yr old, or subadult, will be similar to an osprey with a whitish head with a line
through the eye and a whitish tail with a black line along the end of the tail.
Found only in North America, the bald eagle is also called the American Eagle.
The other eagle native to this continent, the somewhat less rare Golden Eagle,
occurs in other parts of the world as well. The bald eagle is the North American
continent’s second largest bird of prey, surpassed in size only by the California
Condor.
As is true with most birds of prey, the female is almost always larger than the
male. A female bald eagle may stand as much as 107 centimeters (42 inches)
high, with a wingspan of up to 240 centimeters (8 feet). Males stand up to 90
centimeters (35 inches) high, with wingspans of nearly 200 centimeters (6 1/2
feet). Body weights of bald eagles range from 3.6 to 6.4 kilograms (8 to 14
pounds), with females generally about a kilogram heavier than males.
through the eye and a whitish tail with a black line along the end of the tail.
Found only in North America, the bald eagle is also called the American Eagle.
The other eagle native to this continent, the somewhat less rare Golden Eagle,
occurs in other parts of the world as well. The bald eagle is the North American
continent’s second largest bird of prey, surpassed in size only by the California
Condor.
As is true with most birds of prey, the female is almost always larger than the
male. A female bald eagle may stand as much as 107 centimeters (42 inches)
high, with a wingspan of up to 240 centimeters (8 feet). Males stand up to 90
centimeters (35 inches) high, with wingspans of nearly 200 centimeters (6 1/2
feet). Body weights of bald eagles range from 3.6 to 6.4 kilograms (8 to 14
pounds), with females generally about a kilogram heavier than males.
How Do I know A Bald Eagle When I See One?
In addition to their large size, adult bald eagles are identified by their snowy white
head and tail feathers. However, a young bald eagle does not get these white
feathers until it reaches sexual maturity in its fourth or fifth year of life. Immature
bald eagles are a mottled light and dark brown all over, and in flight they often are
mistaken for golden eagles or turkey vultures.
Osprey are often mistaken for bald eagles, but with a little close observation can
be easily identified. The osprey has a smaller head, that is white, with a black line
going through the eye. Some 4 year old eagles will show this same black line, so
the wing shape is the best identification. The osprey has a narrower wing than
the bald eagle and normally has a crook in it, while the bald eagle wing will be
straight.
In addition to their large size, adult bald eagles are identified by their snowy white
head and tail feathers. However, a young bald eagle does not get these white
feathers until it reaches sexual maturity in its fourth or fifth year of life. Immature
bald eagles are a mottled light and dark brown all over, and in flight they often are
mistaken for golden eagles or turkey vultures.
Osprey are often mistaken for bald eagles, but with a little close observation can
be easily identified. The osprey has a smaller head, that is white, with a black line
going through the eye. Some 4 year old eagles will show this same black line, so
the wing shape is the best identification. The osprey has a narrower wing than
the bald eagle and normally has a crook in it, while the bald eagle wing will be
straight.
What do Eagles Eat?
Sixty to ninety percent of a bald eagle’s diet consists of fish. The birds generally
scavenge dead fish, although they will catch live fish as well. They will take an
occasional heron, crow, grouse, duck, gull, or small mammal, especially if fish
are not available. They will feed on dead animals, if other food is not found. This
includes dead animals, such as road killed raccoon or deer, as well as chickens
and small pigs, which farmers may throw out with their manure during the winter.
During deer season bald eagles may come down to feed on the innerds of the
deer that the hunters leave behind.
The bald eagle is an opportunist and will sometimes steal fish from an osprey or
crow. But ospreys have been observed stealing fish from young eagles as well.
The bald eagle uses several fishing techniques. A favorite method is to perch in a
tree and watch for a fish swimming in open water nearby, and then swoop down
to capture it. If a suitable tree is not available near the water for perching, the birds
may also fly out over open water looking for fish below. In winter, they may perch
on the edge of ice near open water and wait for fish to float by, or to wash up on
the ice.
Sixty to ninety percent of a bald eagle’s diet consists of fish. The birds generally
scavenge dead fish, although they will catch live fish as well. They will take an
occasional heron, crow, grouse, duck, gull, or small mammal, especially if fish
are not available. They will feed on dead animals, if other food is not found. This
includes dead animals, such as road killed raccoon or deer, as well as chickens
and small pigs, which farmers may throw out with their manure during the winter.
During deer season bald eagles may come down to feed on the innerds of the
deer that the hunters leave behind.
The bald eagle is an opportunist and will sometimes steal fish from an osprey or
crow. But ospreys have been observed stealing fish from young eagles as well.
The bald eagle uses several fishing techniques. A favorite method is to perch in a
tree and watch for a fish swimming in open water nearby, and then swoop down
to capture it. If a suitable tree is not available near the water for perching, the birds
may also fly out over open water looking for fish below. In winter, they may perch
on the edge of ice near open water and wait for fish to float by, or to wash up on
the ice.
After catching a fish the eagle will either fly back to a perching tree to eat it, or if the
fish is small enough, swallow the fish whole while the bird is in flight.
Occasionally, eagles will carry a larger fish they have caught back to the ice or to
the shore to be eaten. In over 80% of their feeding, wintering bald eagles along the
Mississippi River, feed upon small fish they can eat while flying.
fish is small enough, swallow the fish whole while the bird is in flight.
Occasionally, eagles will carry a larger fish they have caught back to the ice or to
the shore to be eaten. In over 80% of their feeding, wintering bald eagles along the
Mississippi River, feed upon small fish they can eat while flying.
Photo by Les Zigurski from les@wildlifeimagesbyles.net
How Do Bald Eagles Nest?
It has been stated for many years that a Bald Eagle pair will mate for life, but if one
partner dies, or disappears, the other will if lucky find another mate. A newly
bonded pair may work several years on a nest before actually breeding. They may
desert one nest site and start again somewhere else, usually within 1/2 mile.
A northern bald eagle will begin to nest sometime in February or April. A southern
bald eagle will begin to nest in December and January Each nesting pair will
spend a great amount of time preparing the nest before any egg is laid. The
successful nest is generally located in a large tree, within one mile from water,
either a lake or river, where adequate food is available.
Bald eagle nests are generally found from 15 to 36 meters (50 to 120 feet) above
the ground, in a tall, sturdy tree. It takes at least two weeks for a pair of eagles to
build their nest.
A typical bald eagle nest (eyrie) will range from 1.8 to 3 meters (6-10 feet) in
diameter and about 1.8 to 3 meters (6 to 10 feet) high. The nest cavity, where the
eggs are laid, will be about 30 to 40 centimeters (12 to 16 inches) in diameter and
about 10 centimeters (4 inches) deep.
A pair of eagles, once established, may use the same nest several times over a
period of years. Each year more materials are added to the nest, which increases
the size of the nest each year that it is used. Nests weighing up to 2 tons have
been found.
A Vermillion, Ohio nest measured 2.6 meters across its top and was 3.6 meters
high and weighed nearly 1,000 kilograms! Sometimes, eagles will build more
than one nest and use them alternately.
An eagle nest is constructed from large sticks, which are laid together to form the
outside part of the nest. The center of the nest is filled with dead weeds, stubble
and other softer materials, which may be available in the area. The nest cavity
where the eggs are laid is lined with grass, dry moss and feathers.
Many authorities believe that some bald eagles show such a strong attraction to
their nesting site that, if displaced or overly disturbed, a pair may not return to the
nest the following year. This fact places great importance on protecting nesting
areas from disturbances such as logging operations, land development and
recreational activities.
Human activity in the area of a nest during the breeding season must be strictly
controlled to avoid disturbance to the nesting bald eagles. The United States
Forest Service has developed, and is presently enforcing, human activity controls
in bald eagle nesting areas in the National Forests of Minnesota, Michigan,
Wisconsin, and Arizona. This may be a great part of the reason the bald eagles
population has recovered so well in the past 40 years.
The female eagle will normally lay two eggs, and occasionally three, which are
about the size of a goose egg (74.4 mm x 57.1 m.) and colored dull white or pale
bluish white. Both parents incubate or brood the eggs, which take 34 to 35 days to
hatch, and care for the young eaglets. These eaglets remain in the nest for
another 12 to 13 weeks before taking their first flight.
After learning to fly and feed themselves, the young immature eagles are allowed
to return to the nest for the remainder of the summer. But most young eagles are
usually not observed near their parent’s nest after the first year.
Where in the United States are Bald Eagles Found?
The search for food forces bald eagles, which nest in the northern United States
and Canada, to migrate south in late autumn and early winter, when lakes and
rivers in their nesting grounds freeze over. Congregations of these birds may be
seen during the winter along lakes and rivers where there is open water, often
near dams and power plants.
Primarily fish eating birds, they are found along the coasts of North America and
along inland lakes and rivers from the Gulf of Mexico to the Arctic. The birds will
winter as far north as ice free water permits. At some time during the year, a bald
eagle may be seen in nearly every state in the continental U.S. (there are none in
Hawaii).
A majority of Bald Eagles nest in Alaska and remote areas of Canada. A small
number nest in the United States in areas where isolation can still be maintained.
Major nesting areas are concentrated in: the Far West, (Alaska, the San Juan
Islands off the coast of Washington, as well as Washington, Oregon, and northern
California); the Upper Midwest (central and northern Minnesota, northern
Wisconsin and upper Michigan); and the East Coast (Maine, the Chesapeake Bay
area, and Florida).
During winter months, bald eagles are widely scattered throughout much of the
continental U.S. Substantial numbers may be found along the Upper Mississippi
River and its larger tributaries. Smaller concentrations may be found in other
areas, including the deserts of the West and Southwest.
How Many Bald Eagles Are There In North America?
This question is almost impossible to answer. Even if an exact number could be
obtained, it would change from one year to the next. Also, because of the migratory
habits of bald eagles, estimates of the populations are extremely difficult to make
and may be misleading.
Based on several years of surveys in the United States and Canada, the total bald
eagle population of North America is estimated to be somewhere between 35,000
and 50,000. That Seems Like Many Bald Eagles!
Why Should We Be So Worried About Their Fate?
There are relatively large eagle populations in Alaska and Canada. Alaska, for
example, is thought to have approximately 10,000 nesting pairs, Saskatchewan
Province alone is estimated to have between 3500 and 4000 pairs. 0ver 3000
pairs are believed to exist in Canada in addition to Saskatchewan.
Prime nesting areas in the United States are unevenly distributed in Florida,
Wisconsin, Minnesota, Michigan, Oregon & Washington. There are close to 400
active nests in National Forests alone, and perhaps as many on state and private
lands.
Twenty five years ago most states had no nesting bald eagles at all. However, in
the last few years many states have had one to thirty pairs of bald eagles
successfully raise young. It is this low number of bald eagles in the lower 48
states, where large numbers once existed, which prompts concern for the fate of
the species.
Now we are seeing an eight year decline in the percentages of young that are
surviving to winter. What the reason is for this decline is unknown. The exact
reason for the decline in the 1950s is unknown as well. The Fish & Wildlife
Services states that the eagles declined in the 1950s because of DDT. The
problem with that statement is the fact that the bald eagle was recovering for many
years before the nation banned DDT.
How Close To Extinction Is The Bald Eagle?
The answer could be (and often has been!) debated for hours. Some recent
events give encouragement to the belief that the species will never become extinct.
Bald eagle eggs from Wisconsin and Minnesota have been transplanted
successfully into nests in Maine, where the population suffered a decline in
reproductive success because of pesticide contamination.
Young eagles have been successfully transplanted into nests in Maine, New York,
Kentucky, Tennessee, Georgia, Indiana and Missouri. Illinois and Iowa now have
more bald eagles nesting within their borders than they have had for more than 70
years. So there is hope for the eagles’ future.
At the same time, there is a constant struggle to protect essential vital habitat
against human disturbance and destruction. The threat of toxic chemicals in their
food supply continues.
Wait A Minute!
DDT And Dieldrin Are Banned In The U.S. So They are No Longer A Threat To The
Bald Eagle, Right?
Wrong! Although DDT and dieldrin are no longer used in the U.S. without
goverment consent, their manufacture continues. United States corporations
export large quanities of DDT and other pesticides to foreign countries where their
use is legal and widespread. Some U.S. communities are once again trying to get
permission to use DDT to kill mosquitoes for fear of West Nile Virus. These
chemicals are constantly finding their way back to North America through the food
chain. As long as these chemicals, whose residues persist in the environment for
many years, are being used in other parts of the world, they continue to pose a
global threat to wildlife.
Do Other Chemicals Pose A Threat to Bald Eagles?
During the 1970’s, PCB’s (polychlorinated biphenyls) received as much attention
as DDT received in the 1960’s. PCB’s are used primarily as an insulating and
cooling fluid in electrical transformers. They are known to cause cancer. They are
widespread in the environment and persist without breaking down for many years.
Like pesticide residues, PCB’s accumulate in larger amounts at higher levels in
food chains. There is evidence that PCB’s interfere with reproduction in wildlife.
Heavy metals such as lead and mercury are widespread in the environment. Lead
used to be found in a wide variety of products, from gasoline to shotgun shells.
Mercury is used in many industrial processes, such as paper and chemical
manufacture.
When they enter the bald eagle’s food chain, these metals pose a threat. In
Minnesota, bald eagles feeding on Canada Geese killed or crippled with lead shot
were found to have elevated levels of lead in their blood.
Lead is known to reduce the blood’s ability to transport oxygen, which will limit an
eagle’s ability to fly very far. In Maine, where there are many paper mills, infertile
bald eagle eggs have been found to have a higher mercury content than eggs from
other areas.
The nation’s large chemical companies like Monsanto and Bayer are constantly
developing new and stronger chemicals that are used by farmers and
homeowners. There is a real threat that one or more of these chemicals are
working their way into the food chain like DDT did.
What Are The Penalties For Killing A Bald Eagle?
A federal law protecting both the bald and golden eagle specifies fines of up to
$10,000 and/or a maximun of one year in jail, for the intentional killing of one of
these magnificent birds. The penalty could be double that for the second killing.
How Much Disturbance Will A Bald Eagle Tolerate?
Bald eagles fear humans at all times, but will tolerate much less disturbance
during the nesting season, than at other times of the year. A nesting pair will seek
isolation, and any human interference, if prolonged, may drive the birds away from
the nest.
How Do Bald Eagles Nest?
It has been stated for many years that a Bald Eagle pair will mate for life, but if one
partner dies, or disappears, the other will if lucky find another mate. A newly
bonded pair may work several years on a nest before actually breeding. They may
desert one nest site and start again somewhere else, usually within 1/2 mile.
A northern bald eagle will begin to nest sometime in February or April. A southern
bald eagle will begin to nest in December and January Each nesting pair will
spend a great amount of time preparing the nest before any egg is laid. The
successful nest is generally located in a large tree, within one mile from water,
either a lake or river, where adequate food is available.
Bald eagle nests are generally found from 15 to 36 meters (50 to 120 feet) above
the ground, in a tall, sturdy tree. It takes at least two weeks for a pair of eagles to
build their nest.
A typical bald eagle nest (eyrie) will range from 1.8 to 3 meters (6-10 feet) in
diameter and about 1.8 to 3 meters (6 to 10 feet) high. The nest cavity, where the
eggs are laid, will be about 30 to 40 centimeters (12 to 16 inches) in diameter and
about 10 centimeters (4 inches) deep.
A pair of eagles, once established, may use the same nest several times over a
period of years. Each year more materials are added to the nest, which increases
the size of the nest each year that it is used. Nests weighing up to 2 tons have
been found.
A Vermillion, Ohio nest measured 2.6 meters across its top and was 3.6 meters
high and weighed nearly 1,000 kilograms! Sometimes, eagles will build more
than one nest and use them alternately.
An eagle nest is constructed from large sticks, which are laid together to form the
outside part of the nest. The center of the nest is filled with dead weeds, stubble
and other softer materials, which may be available in the area. The nest cavity
where the eggs are laid is lined with grass, dry moss and feathers.
Many authorities believe that some bald eagles show such a strong attraction to
their nesting site that, if displaced or overly disturbed, a pair may not return to the
nest the following year. This fact places great importance on protecting nesting
areas from disturbances such as logging operations, land development and
recreational activities.
Human activity in the area of a nest during the breeding season must be strictly
controlled to avoid disturbance to the nesting bald eagles. The United States
Forest Service has developed, and is presently enforcing, human activity controls
in bald eagle nesting areas in the National Forests of Minnesota, Michigan,
Wisconsin, and Arizona. This may be a great part of the reason the bald eagles
population has recovered so well in the past 40 years.
The female eagle will normally lay two eggs, and occasionally three, which are
about the size of a goose egg (74.4 mm x 57.1 m.) and colored dull white or pale
bluish white. Both parents incubate or brood the eggs, which take 34 to 35 days to
hatch, and care for the young eaglets. These eaglets remain in the nest for
another 12 to 13 weeks before taking their first flight.
After learning to fly and feed themselves, the young immature eagles are allowed
to return to the nest for the remainder of the summer. But most young eagles are
usually not observed near their parent’s nest after the first year.
Where in the United States are Bald Eagles Found?
The search for food forces bald eagles, which nest in the northern United States
and Canada, to migrate south in late autumn and early winter, when lakes and
rivers in their nesting grounds freeze over. Congregations of these birds may be
seen during the winter along lakes and rivers where there is open water, often
near dams and power plants.
Primarily fish eating birds, they are found along the coasts of North America and
along inland lakes and rivers from the Gulf of Mexico to the Arctic. The birds will
winter as far north as ice free water permits. At some time during the year, a bald
eagle may be seen in nearly every state in the continental U.S. (there are none in
Hawaii).
A majority of Bald Eagles nest in Alaska and remote areas of Canada. A small
number nest in the United States in areas where isolation can still be maintained.
Major nesting areas are concentrated in: the Far West, (Alaska, the San Juan
Islands off the coast of Washington, as well as Washington, Oregon, and northern
California); the Upper Midwest (central and northern Minnesota, northern
Wisconsin and upper Michigan); and the East Coast (Maine, the Chesapeake Bay
area, and Florida).
During winter months, bald eagles are widely scattered throughout much of the
continental U.S. Substantial numbers may be found along the Upper Mississippi
River and its larger tributaries. Smaller concentrations may be found in other
areas, including the deserts of the West and Southwest.
How Many Bald Eagles Are There In North America?
This question is almost impossible to answer. Even if an exact number could be
obtained, it would change from one year to the next. Also, because of the migratory
habits of bald eagles, estimates of the populations are extremely difficult to make
and may be misleading.
Based on several years of surveys in the United States and Canada, the total bald
eagle population of North America is estimated to be somewhere between 35,000
and 50,000. That Seems Like Many Bald Eagles!
Why Should We Be So Worried About Their Fate?
There are relatively large eagle populations in Alaska and Canada. Alaska, for
example, is thought to have approximately 10,000 nesting pairs, Saskatchewan
Province alone is estimated to have between 3500 and 4000 pairs. 0ver 3000
pairs are believed to exist in Canada in addition to Saskatchewan.
Prime nesting areas in the United States are unevenly distributed in Florida,
Wisconsin, Minnesota, Michigan, Oregon & Washington. There are close to 400
active nests in National Forests alone, and perhaps as many on state and private
lands.
Twenty five years ago most states had no nesting bald eagles at all. However, in
the last few years many states have had one to thirty pairs of bald eagles
successfully raise young. It is this low number of bald eagles in the lower 48
states, where large numbers once existed, which prompts concern for the fate of
the species.
Now we are seeing an eight year decline in the percentages of young that are
surviving to winter. What the reason is for this decline is unknown. The exact
reason for the decline in the 1950s is unknown as well. The Fish & Wildlife
Services states that the eagles declined in the 1950s because of DDT. The
problem with that statement is the fact that the bald eagle was recovering for many
years before the nation banned DDT.
How Close To Extinction Is The Bald Eagle?
The answer could be (and often has been!) debated for hours. Some recent
events give encouragement to the belief that the species will never become extinct.
Bald eagle eggs from Wisconsin and Minnesota have been transplanted
successfully into nests in Maine, where the population suffered a decline in
reproductive success because of pesticide contamination.
Young eagles have been successfully transplanted into nests in Maine, New York,
Kentucky, Tennessee, Georgia, Indiana and Missouri. Illinois and Iowa now have
more bald eagles nesting within their borders than they have had for more than 70
years. So there is hope for the eagles’ future.
At the same time, there is a constant struggle to protect essential vital habitat
against human disturbance and destruction. The threat of toxic chemicals in their
food supply continues.
Wait A Minute!
DDT And Dieldrin Are Banned In The U.S. So They are No Longer A Threat To The
Bald Eagle, Right?
Wrong! Although DDT and dieldrin are no longer used in the U.S. without
goverment consent, their manufacture continues. United States corporations
export large quanities of DDT and other pesticides to foreign countries where their
use is legal and widespread. Some U.S. communities are once again trying to get
permission to use DDT to kill mosquitoes for fear of West Nile Virus. These
chemicals are constantly finding their way back to North America through the food
chain. As long as these chemicals, whose residues persist in the environment for
many years, are being used in other parts of the world, they continue to pose a
global threat to wildlife.
Do Other Chemicals Pose A Threat to Bald Eagles?
During the 1970’s, PCB’s (polychlorinated biphenyls) received as much attention
as DDT received in the 1960’s. PCB’s are used primarily as an insulating and
cooling fluid in electrical transformers. They are known to cause cancer. They are
widespread in the environment and persist without breaking down for many years.
Like pesticide residues, PCB’s accumulate in larger amounts at higher levels in
food chains. There is evidence that PCB’s interfere with reproduction in wildlife.
Heavy metals such as lead and mercury are widespread in the environment. Lead
used to be found in a wide variety of products, from gasoline to shotgun shells.
Mercury is used in many industrial processes, such as paper and chemical
manufacture.
When they enter the bald eagle’s food chain, these metals pose a threat. In
Minnesota, bald eagles feeding on Canada Geese killed or crippled with lead shot
were found to have elevated levels of lead in their blood.
Lead is known to reduce the blood’s ability to transport oxygen, which will limit an
eagle’s ability to fly very far. In Maine, where there are many paper mills, infertile
bald eagle eggs have been found to have a higher mercury content than eggs from
other areas.
The nation’s large chemical companies like Monsanto and Bayer are constantly
developing new and stronger chemicals that are used by farmers and
homeowners. There is a real threat that one or more of these chemicals are
working their way into the food chain like DDT did.
What Are The Penalties For Killing A Bald Eagle?
A federal law protecting both the bald and golden eagle specifies fines of up to
$10,000 and/or a maximun of one year in jail, for the intentional killing of one of
these magnificent birds. The penalty could be double that for the second killing.
How Much Disturbance Will A Bald Eagle Tolerate?
Bald eagles fear humans at all times, but will tolerate much less disturbance
during the nesting season, than at other times of the year. A nesting pair will seek
isolation, and any human interference, if prolonged, may drive the birds away from
the nest.
During the winter, eagles will roost and feed in groups close to human habitation
and activity. However, prolonged and repeated disturbances will send the birds on
their way in search of another isolated roost or feeding area. Any disturbance that
Disturbances at these sites can lessen the eagles’ survival chances as secondary
roosts if available, will in all probability not have the vital weather protection that the
primary roost provided.
What Kinds Of Land-Use Practices Have Adverse Effects On Bald Eagle Habitat?
Eagles, being large birds, need large strong trees for nesting, roosting, and
perching while hunting. Most trees have to be over 200 years old before they can
be used as nesting sites for the bald eagle. Logging operations have disturbed or
destroyed many nesting territories and potential nest sites, as well as winter
roosts. U.S. Forest Service regulations protect nesting territories in the National
Forests. But nests and roosts on private land may not be protected, and many
times nesting trees used by eagles may be cut down, before their existence is
known to the scientific community or general public.
Intensive recreational use of land near nests and roosts disturbs the birds.
Increased traffic from snowmobiles, and all terrain vehicles, presents a serious
problem, which must be addressed. As the human population expands and
moves in greater numbers back into the countryside, the bald eagle is pushed
back into smaller and smaller pockets of suitable habitat. Forests are cleared for
farming. Vacation homes are built on the shores of lakes where bald eagles nest.
In Illinois, the Central Illinois Expressway was constructed right up a valley that
eagles used for a winter nighttime roost. In Maine and Washington, supertanker
ports and oil refineries have been built near bald eagle roosting and wintering
areas. All too often the eagle is forced, by people, to give in and move elsewhere.
Most Bald Eagles Nest In The Northern United States And Canada - Where There
Is Plenty Of Suitable Habitat,
So Why Is It Necessary To Protect Nesting Sites?
The critical point to remember is that bald eagles are very territorial birds, and
most breeding pairs return to the same nest site year after year. They may use the
same nest annually for as many as 35 years, or they may build additional nests in
their nesting territory, and alternate the use of them from year to year.
If their nests are disturbed or destroyed, the pair may never build again. So,
although there are large tracts of wild land available to bald eagles, the territorial
nature of the birds, their precise nesting requirements, and their past nesting
habits, limit the number of suitable nest sites.
Why Are Winter Roosting Sites So Important?
Just as human beings need a warm, sheltered place to go during severe winter
weather, so do bald eagles. Winter can be a time of great stress on all wildlife. If
that stress can be reduced, there will be a larger and healthier breeding population
to migrate North the following spring.
Where Do Bald Eagles Roost In Winter?
Bald eagles generally choose to roost in large trees in protected places within
eight miles of their feeding grounds. Along the Mississippi River, for example, they
most often roost in heavily wooded, steep-sided valleys, sheltered from northerly
winds, or in cottonwoods on islands away from human disturbance.
Bald eagle winter roosting areas have been identified in many parts of the United
States - Cobscook and Frenchman Bays in Maine, the Delaware River in southern
New York, the Salt Plains National Wildlife refuge in Oklahoma, the San Luis River
Valley in southern Colorado, Navajo Lake in northern New Mexico, and the Skagit
River Bald Eagle Natural Area in Washington, just to mention a few.
By far the nation’s most important bald eagle winter roosting sites are found along
the Upper Mississippi River watershed. They include: Ferry Bluff on the Wisconsin
River; Eagle Valley, Oak Valley, the Savanna Army Depot, Clarksville and Burlington
Islands on the Mississippi River; Rice Lake on the Illinois River, Swan Lake and
Squaw Creek on the Missouri River; and Land Between the Lakes in Kentucky, and
Reelfoot Lake in Tennessee. We presently know of 59 bald eagle winter roosts
that are located on both private and public land along the Mississippi and its major
tributaries.
Are All Of These Winter Roosts Protected?
Not by a long shot. Some - Ferry Bluff, Oak Valley, Eagle Valley, Cedar Glenn, the
Savanna Army Depot and Plum Island, for example-are protected by conservation
organizations or government agencies that manage them. Others are in private
hands and are still open to development. Still others are only partially protected
and thus threatened by nearby development.
Unlike nesting sites, most of which are in remote areas, many wintering grounds
are close to large numbers of people. Human contact with the eagles is inevitable
and disturbance of the birds a constant threat. Not to be overlooked is the fact that
the use of favored roosting sites varies from year to year, depending on the
availability of food. Thus, it is important to preserve as much of the natural
ecosystem of these wintering areas as possible. Many are not protected at all.
Why Do Private Organizations Have To Get Involved?
Isn’t 0ur Government Supposed To Be Doing This?
Government agencies have a variety of programs which are supposed to help the
bald eagle. The U.S. Fish and Wildlife Service is supposed to be keeping a watch
on eagle numbers, and maintains laboratories which investigate the causes of
death of eagles and other wildlife. The U.S. Forest Service protects and manages
bald eagle nesting territories, monitors nesting success and in the past has
surveyed bald eagle populations. The Bureau of Land Management and the U.S.
Army Corps of Engineers have in the past instituted policies to help protect bald
eagles.
However, bald eagles don’t nest, roost and hunt just on government land. Also,
government policies often force the eagle to take a back seat to other priorities.
The Forest Service’s policy of multiple use, and the Corps of Engineers’ mandate
to develop waterways, may conflict with the life requirements of the bald eagle.
Thus, private organizations must get involved if the bald eagle is to survive.
What Research Is Being Done To Learn More About The Bald Eagle?
Bald eagles have only recently been the focus of intensive research, and a great
deal of useful information is being gathered about their nesting behavior, feeding
habits, roosting patterns, and their migrations. Researchers use a variety of
techniques to study the birds. Nests are observed with closed circuit TV cameras.
Individual birds are outfitted with leg bands as nestlings, so they can be identified
later in life. Movements of eagles are tracked using colored markers or radio
transmitters on the birds. The results of these research efforts are presented at
scientific meetings such as International Bald Eagle Days, sponsored by the Eagle
Nature Foundation.
and activity. However, prolonged and repeated disturbances will send the birds on
their way in search of another isolated roost or feeding area. Any disturbance that
Disturbances at these sites can lessen the eagles’ survival chances as secondary
roosts if available, will in all probability not have the vital weather protection that the
primary roost provided.
What Kinds Of Land-Use Practices Have Adverse Effects On Bald Eagle Habitat?
Eagles, being large birds, need large strong trees for nesting, roosting, and
perching while hunting. Most trees have to be over 200 years old before they can
be used as nesting sites for the bald eagle. Logging operations have disturbed or
destroyed many nesting territories and potential nest sites, as well as winter
roosts. U.S. Forest Service regulations protect nesting territories in the National
Forests. But nests and roosts on private land may not be protected, and many
times nesting trees used by eagles may be cut down, before their existence is
known to the scientific community or general public.
Intensive recreational use of land near nests and roosts disturbs the birds.
Increased traffic from snowmobiles, and all terrain vehicles, presents a serious
problem, which must be addressed. As the human population expands and
moves in greater numbers back into the countryside, the bald eagle is pushed
back into smaller and smaller pockets of suitable habitat. Forests are cleared for
farming. Vacation homes are built on the shores of lakes where bald eagles nest.
In Illinois, the Central Illinois Expressway was constructed right up a valley that
eagles used for a winter nighttime roost. In Maine and Washington, supertanker
ports and oil refineries have been built near bald eagle roosting and wintering
areas. All too often the eagle is forced, by people, to give in and move elsewhere.
Most Bald Eagles Nest In The Northern United States And Canada - Where There
Is Plenty Of Suitable Habitat,
So Why Is It Necessary To Protect Nesting Sites?
The critical point to remember is that bald eagles are very territorial birds, and
most breeding pairs return to the same nest site year after year. They may use the
same nest annually for as many as 35 years, or they may build additional nests in
their nesting territory, and alternate the use of them from year to year.
If their nests are disturbed or destroyed, the pair may never build again. So,
although there are large tracts of wild land available to bald eagles, the territorial
nature of the birds, their precise nesting requirements, and their past nesting
habits, limit the number of suitable nest sites.
Why Are Winter Roosting Sites So Important?
Just as human beings need a warm, sheltered place to go during severe winter
weather, so do bald eagles. Winter can be a time of great stress on all wildlife. If
that stress can be reduced, there will be a larger and healthier breeding population
to migrate North the following spring.
Where Do Bald Eagles Roost In Winter?
Bald eagles generally choose to roost in large trees in protected places within
eight miles of their feeding grounds. Along the Mississippi River, for example, they
most often roost in heavily wooded, steep-sided valleys, sheltered from northerly
winds, or in cottonwoods on islands away from human disturbance.
Bald eagle winter roosting areas have been identified in many parts of the United
States - Cobscook and Frenchman Bays in Maine, the Delaware River in southern
New York, the Salt Plains National Wildlife refuge in Oklahoma, the San Luis River
Valley in southern Colorado, Navajo Lake in northern New Mexico, and the Skagit
River Bald Eagle Natural Area in Washington, just to mention a few.
By far the nation’s most important bald eagle winter roosting sites are found along
the Upper Mississippi River watershed. They include: Ferry Bluff on the Wisconsin
River; Eagle Valley, Oak Valley, the Savanna Army Depot, Clarksville and Burlington
Islands on the Mississippi River; Rice Lake on the Illinois River, Swan Lake and
Squaw Creek on the Missouri River; and Land Between the Lakes in Kentucky, and
Reelfoot Lake in Tennessee. We presently know of 59 bald eagle winter roosts
that are located on both private and public land along the Mississippi and its major
tributaries.
Are All Of These Winter Roosts Protected?
Not by a long shot. Some - Ferry Bluff, Oak Valley, Eagle Valley, Cedar Glenn, the
Savanna Army Depot and Plum Island, for example-are protected by conservation
organizations or government agencies that manage them. Others are in private
hands and are still open to development. Still others are only partially protected
and thus threatened by nearby development.
Unlike nesting sites, most of which are in remote areas, many wintering grounds
are close to large numbers of people. Human contact with the eagles is inevitable
and disturbance of the birds a constant threat. Not to be overlooked is the fact that
the use of favored roosting sites varies from year to year, depending on the
availability of food. Thus, it is important to preserve as much of the natural
ecosystem of these wintering areas as possible. Many are not protected at all.
Why Do Private Organizations Have To Get Involved?
Isn’t 0ur Government Supposed To Be Doing This?
Government agencies have a variety of programs which are supposed to help the
bald eagle. The U.S. Fish and Wildlife Service is supposed to be keeping a watch
on eagle numbers, and maintains laboratories which investigate the causes of
death of eagles and other wildlife. The U.S. Forest Service protects and manages
bald eagle nesting territories, monitors nesting success and in the past has
surveyed bald eagle populations. The Bureau of Land Management and the U.S.
Army Corps of Engineers have in the past instituted policies to help protect bald
eagles.
However, bald eagles don’t nest, roost and hunt just on government land. Also,
government policies often force the eagle to take a back seat to other priorities.
The Forest Service’s policy of multiple use, and the Corps of Engineers’ mandate
to develop waterways, may conflict with the life requirements of the bald eagle.
Thus, private organizations must get involved if the bald eagle is to survive.
What Research Is Being Done To Learn More About The Bald Eagle?
Bald eagles have only recently been the focus of intensive research, and a great
deal of useful information is being gathered about their nesting behavior, feeding
habits, roosting patterns, and their migrations. Researchers use a variety of
techniques to study the birds. Nests are observed with closed circuit TV cameras.
Individual birds are outfitted with leg bands as nestlings, so they can be identified
later in life. Movements of eagles are tracked using colored markers or radio
transmitters on the birds. The results of these research efforts are presented at
scientific meetings such as International Bald Eagle Days, sponsored by the Eagle
Nature Foundation.
| All rights reserved. Eagle Nature Foundation, Ltd. 300 East Hickory Street Apple River, IL 61001 Phone: 815-594-2306 |
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USFWS to put the American
Bald Eagle back on the
Endangered Species List:
Protect the Eagle Now
Follow us on Twitter and
Facebook!
Read the Current Issue of
Nature News or download
the PDF version.