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