Interesting notes: Although the bald eagle is a national symbol of the United States, it did not win this honor without controversy and heated discussion. Benjamin Franklin thought the bald eagle was a "rank coward" and described it as
... a bird of bad moral character; he does not get his living honestly; you may have seen him perched on some dead tree, where, too lazy to fish for himself, he watches the labor of a fishing-hawk; and, when that diligent bird has at length taken a fish, and is bearing it to his nest for the support of his mate and young ones, the bald eagle pursues him, and takes it from him.
Franklin thought the turkey would have been a better symbol for the United States, he felt that it was "in comparison a much more respectable bird" and was also a "bird of courage" (U.S. Department of State 1909).
The largest bird nests in North America are made by bald eagles (Stalmaster 1987). The largest nest ever recorded, found in Florida, was measured to be 20 feet deep and 9½ feet wide (Broley 1947). Another nest, which had been used for over 30 years, blew down during a storm. The remains were collected and weighed. The nest was found to have weighed 1274 pounds, over half a ton (Smith 1936).
The weight of a bald eagle's feathers is greater than that of its skeleton. One study showed the feathers to make up almost one-fifth of the entire weight. This same study found that one bald eagle had more than 7000 feathers on its body (Brodkorb 1955).
The bald eagle's lifting capacity has been greatly overstated. bald eagles have mistakenly been reported carrying off both a 30 pound pig and a 50 pound lamb. Another report stated that a bald eagle was seen eating 40 pounds in one meal. The fact is the bald eagle would do well to carry off one-half of its own body weight, three to seven pounds (Palmer 1988a).
But what happens when a bald eagle underestimates the weight of its prey? In one instance, a bald eagle was observed floating approximately 300 feet off shore stroking the water with its wings and moving towards the shore. When it finally arrived, the eagle jumped up onto a rock and a fish was revealed to be in its talons (Danielsen 1967). In another instance, a bald eagle was observed floating in the water for a period of five to eight minutes while trying to grab a fish. After finally latching onto the fish, and with only its head and wings above the water, it made a strong effort to swim to shore with its catch. Upon reaching the shore it mysteriously gave up its fish and flew off (Baird 1931). Eagles have been known to disregard fish that have accidentally been dropped from their nests (Palmer 1988a), but it isn't known why such a hard fought for meal would suddenly become disregarded.
The number of bald eagles was first noticed to decline back in 1947. The main cause was a pesticide, called DDT, that was used to control another creature found near water, mosquitoes. Since DDT was sprayed around water, it was eventually consumed by fish, the bald eagle's primary food. When the DDT tainted fish were eaten by bald eagles it had the eventual effect of weakening the eagle's egg shells. The eggs would collapse simply from the weight of the mother bald eagle. This same phenomena has also caused the Peregrine Falcon to become endangered (Lowe et al 1990).
DDT was finally banned in the United States (and still is today, even though it is made here and exported to other countries) on December 31, 1972. Although bald eagle populations are starting to recover, as of 1990 it was still listed as "endangered" in most of the United States and "threatened" in Michigan, Minnesota, Oregon, Washington, and Wisconsin. It is not endangered or threatened in Alaska (Gerrard 1988; Grier 1982; Lowe et al 1990).