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Audubon EagleWatch is a program committed to the protection
and conservation of Florida’s Bald Eagles. Click
here for more information about joining this dedicated
group of volunteer citizen scientists, or contact Lynda
White.
Bald Eagle Basics
The Bald Eagle is much more than just the symbol of
America: it personifies strength, majesty and independence.
Yet, its very existence is dependent upon how humans
manage the environment that is shared with all wildlife
species. When chosen as a national symbol in 1782, it
was found abundantly throughout the contiguous United
States. Historically, it has been listed as a federally
endangered species due largely to human ignorance and
persecution by pesticides, careless shootings, car and
powerline collisions and loss of habitat for nesting
and foraging. Under the Endangered Species Act, in 1995,
the species was federally down-listed to threatened
by the U. S. Fish and Wildlife Service due to the resurgence
of nesting eagles in many historic areas throughout
the United States. The Bald Eagle is scheduled to be
removed, or delisted, from the Endangerd Species List
in the near future.
The Bald Eagle is native to our continent and is one
of the largest birds in North America. The Latin name
"Haliaeetus leucocephalus" means "white-headed
sea eagle", referencing its genus classification.
The word "bald" refers to an old English use
of the word meaning "white" since the head
is distinctly feathered. Birds commonly confused with
Bald Eagles include Ospreys, Turkey Vultures, and Golden
Eagles, the latter only occasionally sighted in northern
Florida during the winter migratory months.
Like other birds of prey, Bald Eagles exhibit "reversed
sexual size dimorphism", and females are larger
than males. Female eagles in Florida (the southern subspecies)
weigh from 8-12 pounds and have a wingspread up to eight
feet. Males are smaller, weighing 6-10 pounds, with
a wingspread of six feet. Both sexes have the characteristic
white head and tail, yellow beaks and eyes upon maturity,
a gradual process of four to six years. Young eagles,
called juveniles, are uniformly brown and larger in
size than adults due to longer wing and tail feathers.
Immature and subadult refer to plumage sequences after
the first year and before adulthood, while adult eagles
are also called mature
Adaptations for survival include keen eyesight that
can identify objects three to four times farther away
than humans, operating much like a telescope for focusing;
powerful feet and claws called "talons" to
capture and kill prey; an elongated beak with a sharp
tip adept at tearing food; and well-developed muscles
in the legs and supporting the beak that aid in prey
destruction. Eagles tear and swallow their food in large
pieces, temporarily storing it in an area below the
throat called the "crop" before actual digestion.
The crop is a noticeable bulge when full that can store
over two pounds of prey when food is plentiful
An eagle's call is quite distinctive, ranging from a
short staccato note, a whining call, and also includes
a high pitched scream of descending notes. Vocalizations
serve several purposes including greeting, solicitation,
territorial defense, threat, and begging calls for food
(juveniles).
Food. Eagles are opportunistic scavengers with a prey
base that includes fish, squirrels, wading birds, ducks
and road-killed animals called carrion. Fish is also
pirated from Ospreys in spectacular aerial acrobatics!
General Nesting Information
The nesting season in Florida extends from October
through May, with nests usually located in a live pine
or cypress tree. Nests are often reused year after year,
with some pairs of eagles using an alternate nest within
their defined territory. Man-made structures including
cellular towers and powerline towers are being utilized
in increasing numbers due to loss of suitable nesting
habitat.
Egg laying begins in late November and can occur even
into February if the first nesting attempts are unsuccessful.
Statistics compiled by biologists conducting the Florida
Game and Fresh Water Fish Commission’s annual
aerial Bald Eagle nesting survey indicate that late
season nests experience higher mortality
Clutch size for eggs and eaglets ranges from 2-4, most
commonly two in Florida, with nesting success greatly
dependent upon availability of food. Incubation is shared
by both adults with the emergence of hatchlings after
33-35 days. Nestling eaglets are completely feathered
and attain full size by their third month, often venturing
to fly shortly thereafter. Research indicates that there
is no definite pattern of dispersal for young eagles
after fledging, or leaving the nest.
In Florida, due to loss of available habitat for nesting
and concentrations of birds in certain areas, intraspecies
fighting with aggressive aerial territory battles can
occur among eagles throughout the nesting season. Typically,
talon wounds are inflicted on the legs, lower abdomen,
chest and head areas, and in severe disputes, mortality
occurs. Immature eaglets lacking the white head and
tail coloration, are in non-threatening plumage, and
generally will not be attacked by nesting birds, just
escorted out of the territory range
When mature, eagles return to the vicinity of their
original nest sites to breed. That is why there are
concentrations of active nests located around large
lakes throughout Florida. An area’s carrying capacity
is reached when the habitat is saturated with eagles
for the amount of food and nest sites that it can support.
This causes a natural dispersal of birds into new areas
for breeding, including historic ranges and non-traditional
nest sites in urban areas.
Did You Know...
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The Bald Eagle is found only in North
America, and was adopted as America’s symbol
in 1782 (it beat out the Turkey!). |
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Florida has more resident Bald Eagles
than any other state except Alaska. Over 1,200 breeding
pairs of eagles have active nests throughout Florida.
After decades of mortality due to collisions with
cars, electrocutions, poisonings and shootings,
the eagle population has rebounded to between 3,000-4,000
birds statewide. |
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The word “bald” is derived
from an Old English word, “balde”, meaning
“white head”. The scientific name, Haliaeetus
leucocephalus, means “white-headed sea eagle”.
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The Bald Eagle is listed as a threatened
species nationally, with protection of the bird
and its habitat under the Endangered Species Act.
When delisting occurs, the eagle and its nest site
will continue to be protected by the Bald and Golden
Eagle Protection Act and the Migratory Bird Treaty
Act. |
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The Bald Eagle is the fastest-growing bird in North America.
It weighs 4 ounces at birth and can gain 6 ounces a day. At
three months of age, the juvenile can be larger than its parents,
weighing up to 12 pounds. |
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The bones of an eagle weigh less than half the weight of
its feathers. |
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The Bald Eagle is the only bird considered sacred by every
North American Indian tribe, revered for its strength, beauty,
independence, hunting prowess and the power and height of
its flight. |
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Bald Eagles can live 30-40 years in the wild and over 50
years in captivity. |
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Bald Eagles build the largest nest of any North American
bird. One Florida nest measured 9 feet across and weighed
2 tons. |
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Eagles mate for life and usually return to the same nest
each year. |
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Loss of habitat is the biggest threat to the continued recovery
of the species. |
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Bald Eagles are opportunistic feeders. They eat fish primarily,
but are often seen on the side of the road feasting on road-killed
animals. |
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Audubon EagleWatch volunteers currently monitor over 250
urban eagle nests statewide. The data collected is shared
with state and federal wildlife officials. |
Native Americans
and the Bald Eagle
The National
Eagle Repository
For more information about Bald Eagles in Florida,
e-mail Lynda White
or call 407-644-0190.
For information about Audubon Center for Birds
of Prey Adopt-a-Bird program click
here. Adopting an eagle supports the care and rehabilitation
of Florida raptors, also educational programs that build
support for the protection of their habitats in Florida.
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