Barr LakeEagle's Nest |
Eagle's Nest Brochure for Barr Lake State Park (SP) in Colorado. Published by Colorado Parks & Wildlife.
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At 4-6 weeks, the eaglets may be seen moving
about in the nest. New feathers begin to
appear, and the young continue to grow, until
they weigh 5.5 -7.5 pounds.
BALD EAGLE NESTING CHRONOLOGY AT BARR LAKE
COURTSHIP AND NEST BUILDING
EGG LAYING
3-5 DAYS
INCUBATION
35 DAYS
HATCHING
2-3 DAYS
NESTLING PERIOD
72 DAYS
FLEDGING
FAMILY DISPERSAL
NOV
DEC
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
More than eight months are needed for a Bald Eagle pair to successfully raise young. During this time, almost anything can go
wrong. On average, only about half of all eagle nests that are started end successfully with at least one new eagle produced.
This chart explains the phases through which the Barr Lake eagle pair progress in order to raise young.
The Bald Eagles at
Barr Lake
The story of Bald Eagles at Barr Lake probably
began over a hundred years ago, when an
irrigation reservoir was built in an area that
was once a buffalo wallow. As the years
passed, cottonwood trees grew old and tall.
Fish and waterfowl, as well as many other
kinds of wildlife, flourished in and around the
lake.
In 1977, this area was recognized as a valuable
wildlife habitat and Barr Lake became a state
park. Half of the lake was set aside as a
wildlife refuge.
A pair of Bald Eagles has been observed in the
refuge every year since 1986. Since that time,
they have survived storms, the loss of a
nesting tree, and even the disappearance of
the male. After 3 years of failed attempts to
raise young, the Bald Eagle pair was finally
successful in 1989. As of 2005, the Barr Lake
eagle have produced 32 young. Twenty-nine of
these survived to fledge.
habitat, we can look forward to
the presence of these birds and
their young for many years to
come.
An eagle nest may be added to and reused for
as long as 20 years, or a pair may use another
nest site. With continued protection of their
Eaglet Growth and
Development
Newly-hatched eaglets weigh
only 1/4 pound, but will grow
quickly in the first 3 months. A 1-2
week old eaglet already weighs
approximately 2 pounds! The young grow
quickly on a diet of fish and prairie dogs and
they are able to leave the nest at 10-12 weeks
of age.
The Barr Lake eaglets are 3-4 weeks old by
mid-April. With their dark gray, thick, wooly
down, the young look large, but weigh only
3.5 to 5.5 pounds.
From May to June, the
art of self-feeding is
acquired in preparation for fledging.
The wooly down is
replaced by dark
brown feathers,
and the birds
may weigh up
to 11 pounds.
At the time they
fledge, young Bald Eagles are as big as their
parents.
The all-white head and tail of the adult Bald
Eagle takes 4-6 years to develop,
and is a sign of sexual maturity.
How and Where
to See the Eagles
The best viewing of the eagles' nest is from
the Gazebo, only a 1.3-mile walk south of the
Nature Center into the wildlife refuge. The
nest is approximately a quarter mile from the
Gazebo and is easily seen with binoculars. The
Nature Center loans binoculars and features
a display about eagles. The Nature
Center is open Wednesday-Sunday.
Call 303-659-6005 for specific
hours.
The Barr Lake
Bald Eagle Watch
You can participate in studies of the bald
eagles by joining the Bald Eagle Watch.
Volunteers receive training and observe the
birds throughout the nesting period.
During observations, watchers gather important information about eagle behaviors, food
brought to the nest, and general habitat use by
the eagles. If you’re interested in becoming an
eagle watcher, call the Colorado Bird Observatory education line at (303) 637-9220.
The Bald Eagle Watch is administered by the
Rocky Mountain Bird Observatory and Barr
Lake State Park. Funding has been provided
by donations from individuals, agencies,
corporate sponsors, and Rocky Mountain Bird
Observatory members.
The Bald
Eagle Nest at
Barr Lake
Tail feather from an
immature Bald Eagle
A few tips for eagle viewing:
• Bring binoculars or a spotting
scope for viewing the nest.
• Viewing is usually best during the
morning or evening hours, especially on warm days when heat
waves can interfere with your
ability to see.
• The eagles are sensitive to
human activity. Please stay on
designated trails in the wildlife
refuge. Pets are not permitted.
• Stop by the Nature Center for a
look at the display about eagles.
• A park pass is required on all
vehicles.
This brochure
is provided by:
Rocky Mountain Bird Observatory and
Colorado State Parks