The Photography of D L Ennis, and more!


Tuesday, July 04, 2006

Birds of the Mid-Atlantic #15: Bald Eagle

Our national symbol evokes different reactions in different observers. A bald eagle in flight shows grace and power. On the ground, it appears more clumsy, much like other large raptors. Despite its powerful appearance and hunting prowess, in many cases eagles prefer to scavenge or bully smaller hawks such as osprey into giving up their prey. (These habits led Benjamin Franklin to describe it as "a bird of bad moral character.")

Adult Bald Eagle / Photo by Steve Hillebrand (USFWS)

Still, the bald eagle makes for an appropriate national symbol. Because of their large size and charisma, eagles command the attention even of non-birders. One of the most popular bird topics in the DC area this year has been the plight of the Wilson Bridge eagles, who lost their hatchlings because the mother was injured in a fight. (See my posts on the subject here, here, here, here, here, and here.) New York has its red-tailed hawks, but DC has its Beltway eagles.

Bald Eagles Per Party Hour on Christmas Bird Counts, 1950-2004

Bald eagles almost disappeared a half-century ago because of human pressures, primarily from the use of DDT. The latter pesticide weakens the eggs of birds so that few eggs hatch; it had a greater effect on raptors because toxins concentrate in higher amounts as they move up the food chain. Thanks to the banning of DDT and the preservation of habitat, the eagle population has recovered. Eagles are now quite common along large bodies of water in the mid-Atlantic region, especially in winter.

Immature Bald Eagle / Photo by Harrison (USFWS)

Young bald eagles are sometimes mistaken for golden eagles. The best way to tell the two species of eagles apart is by the amount of white. As you can see in the image above, the plumage of young bald eagles is flecked with white, all over the body and the wings. The amount of white differs depending on an individual's age; the key to note is that the white is widespread. Adult golden eagles will be completely brown, without any white. Young golden eagles will have distinct white patches near the tips of the wings and a distinct white band on the tail; other than those two features, the bird will be entirely brown. See the photograph below for an example of an adult golden eagle.

Golden Eagle / Photo by Illinois Raptor Center via Wikipedia

Another mistake that frequently occurs, not so much by birders as by entertainers, is the confusion of a red-tailed hawk's call with that of an eagle. Red-tailed hawks evoke feelings of wildness and fierceness when they scream. A bald eagle's high-pitched call sounds more harsh and whiny. It ill-befits such a majestic-looking bird. Watch for this in movies and television programs; red-tailed hawk calls are often attributed to almost any raptor, but especially to eagles.

Happy Fourth, everyone!

Cross-posted at A DC Birding Blog and Blue Ridge Gazette.



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