The History of Bald Eagles

Early History Much of the history of Bald Eagles in America before European settlers arrived is lost. Native peoples understood a great deal about eagle numbers and where they were found, and eagles have always been important figures in Native American culture. But sadly, much of the early history was lost when, for over a generation, native children were prohibited by the government from learning their native languages in school and often separated from the elders who kept oral traditions alive. So most of what we know about eagles is limited to discoveries after European settlement.

Many ornithologists believe that the eagle population numbered about half a million birds when Columbus arrived in America. Eagles lived on every river and chain of lakes on the continent. When John James Audubon traveled throughout much of the continent painting birds in the early and mid-1800s, he was very concerned about how scarce eagles were becoming. He wrote, "A century hence they will not be here as I see them, Nature will have been robbed of many brilliant charms."

What Happened?
Sure enough, a century after Audubon wrote those prophetic words, eagles were, indeed, gone from most of their early haunts. What had happened to them? A whole variety of things:
  • People competed for the same fish the eagles needed
  • People drained wetlands
  • People cut down forests where eagles nested
  • People shot thousands of eagles. Between 1917 and 1953, over 100,000 eagles were killed in Alaska alone because fishermen were afraid the eagles would eat the fish the people wanted. Some people still sell eagle talons and feathers on the black market.
  • Animals shot by people were eaten by scavenging eagles, who swallowed bullets and lead shot and got lead poisoning
  • People set leg traps for fur-bearing animals like beavers and muskrats, and for wild predators like coyotes and wolves, sometimes accidentally catching and killing eagles.
  • Animals poisoned by people were eaten by scavenging eagles who got poisoned, too.
  • Pesticides that built up in the tissues of fish and other animals were eaten by eagles. Some pesticides build up in fat tissue, and are magnified over time. (See our lesson on DDT.)
  • Factories discharged serious pollutants into rivers without legal limits, killing fish and poisoning eagles
  • When eagles flew near power lines, if their wing feathers touched two wires simultaneously they got electrocuted
  • Eagles scavenging on roadkilled animals were hit by cars.

Scrambled Eggs Instead of Babies
By the end of the 1800s, eagle numbers had dropped dramatically. In the 1930s, people became so concerned that they drafted the Bald Eagle Act, which was passed in 1940. Unfortunately, at the same time, people started using a "miracle pesticide" called DDT to kill mosquitoes. (See the Journey North lesson about DDT) Although DDT probably contributed to the deaths of some eagles, its worst effect on them was to prevent them from reproducing. And the majority of eggs that eagles managed to lay during the late 40s, 50s, and 60s had shells so thin and fragile that the eggs got squashed when the mother eagles tried to incubate them. One of the most frightening things for ornithologists was realizing that as low as eagle counts were, virtually all of the birds sighted were adults. It takes eagles 4 - 6 years to assume their adult plumage, and that meant that for more than 6 years, virtually no baby eagles had been born.

Trying to Help
Bald Eagles are the national emblem of the United States, so naturally Americans wanted to help them. The United States officially declared the Bald Eagle an endangered species in 1967 in all areas of the United States south of the 40th parallel. The Endangered Species Act was passed in 1973, and on July 4, 1976, the US Fish and Wildlife Service officially listed the bald eagle as an endangered species over the entire nation (though it was considered "threatened," not "endangered," in Alaska). Strict enforcement and heavy fines prevented most (but sadly not all) eagle shooting.

Meanwhile, ornithologists were piecing together information about DDT and how it was affecting birds. In 1962, Rachel Carson published a book called Silent Spring, warning people that if we didn't use pesticides more wisely, we'd destroy bird populations and ultimately ourselves, too. Public pressure led to several states banning use of DDT by 1968. In 1972, the new Environmental Protection Agency banned virtually all use of DDT in the United States.

Eagle Numbers on Christmas Bird Counts 1900-2000

Thanks to all this work, eagle numbers started to recover. By the early 1980s, eagles were being seen regularly in more and more places, and immatures were being found once again. DDT remained in eagle tissues, and in the environment, but little by little it was decreasing. And little by little eagle numbers increased. And then faster and faster. First the eagle was removed from the endangered list in Minnesota, Wisconsin, Michigan, Washington and Oregon (it was never considered endangered in Alaska). Then in July, 1995, the US Fish and Wildlife Service upgraded the status of bald eagles in the lower 48 states to threatened.

Currently, 7,066 known nesting pairs exist in the contiguous United States. The Bald Eagle's territory stretches over much of the North American continent. Tens of thousands more live in Alaska and Canada, where their existence never was imperiled.
Eagles are now nesting again in most states, and even near some large cities. How are eagles doing in your area?

In February, 2006, the U.S. Fish and Wildlife Service announced action that could lead to the Bald eagle coming off the endangered species list within the next year or so. Fish and Wildlife experts say this change in status won't change the way eagles are managed and protected. Bald eagles and their habitat will continue to be protected.

Try This! Rooting out the Problem
Go back to the list of things that happened to reduce eagle numbers. Which of them are still happening today? Which have stopped happening and why? Based on your answers, which do you think were CRITICAL for eagle populations, and which were not? To learn more, see our lesson on Eagle Populations.