What Time is it in Nature: Bald Eagle
We’ve had some very interesting bird sightings at Prairie Ridge over the last few months! A lot of people have come to see the American Bittern since its first appearance in November, and there have been a variety of birds of prey sighted recently. One of the most spectacular birds we’ve seen has been the Bald Eagle (Haliaeetus leucocephalus).
Though nearly all Americans know what Bald Eagles look like, let’s cover the basics! Bald Eagles are large birds in the Accipitridae family, the day-feeding birds of prey. Adult birds are quite large, with heights reaching over 3 feet and wingspans of over 6 feet. This makes Bald Eagles one of the largest birds in the country and just edges out the Great Blue Heron for the largest wingspan. They have large heads and long, hooked bills. Adult birds have dark brown feathers covering most of their bodies, but have white tails and the iconic white head feathers that most people associate with the species. However, they acquire the white feathers over time and have brown heads in their juvenile stage, making them a little more difficult to instantly identify as immatures.
While Bald Eagles primarily eat fish, they have been known to eat other animals associated with water, such as gulls and waterfowl, and a variety of mammals. They don’t always hunt their own prey, however. Sometimes they’ll take advantage of carrion and they are known to steal food from other birds. For example, a Bald Eagle may harass an Osprey carrying a fish until it drops the fish, then swoop in and grab the fish as it falls. Bald Eagles have even been known to eat garbage from time to time!
Bald Eagles make enormous nests, usually 5-6 feet in diameter and 2-3 feet deep but occasionally reaching much larger sizes. Nests consist of sticks chosen by both members of a mating pair and woven together primarily by the female. The pair will then fill the gaps between the sticks with plant materials and line the nest with soft materials such as lichens and downy feathers. A nest can take up to three months to build, but they may be used year after year. Eventually the female will lay 1-3 eggs in the nest, then the pair will take turns incubating the eggs for over a month and care for the young in the nest for a further 2-3 months. Once the offspring leave the nest, the juvenile eagles will spend the next four years exploring, sometimes flying a hundred miles in a day, before settling into more stable territories.
The Bald Eagle that we’ve spotted at Prairie Ridge is a juvenile and is likely in its exploratory phase, but it has been spotted several times over the last week. Our eagle is a little outside of its usual winter range, so we’ve been excited to see it! If you’d like a chance to spot the eagle, visit Prairie Ridge soon and look up. If you see a massive dark brown bird with wings held mostly flat as it flies (not in the distinctive V-shape of the vultures), you’re probably looking at the Bald Eagle. Good luck!
What Time is it in Nature is a weekly feature highlighting the current plants, animals, and other wildlife at the Musuem’s public outdoor facility, Prairie Ridge Ecostation. Find out more about the natural happenings at Prairie Ridge at our What Time is it in Nature Archive!
(Photo by Yathin S Krishnappa, used under Creative Commons license)