How did the bald eagle get delisted as an endangered species?

By: Cristen Conger | Updated: Jun 7, 2024

Key Takeaways

The bald eagle was removed from the endangered species list after extensive conservation efforts, including the banning of DDT in 1972 and protection under the Endangered Species Act.
These measures helped increase the population from 417 nesting pairs in 1963 to nearly 10,000 pairs by 2007.
Key actions included legal protection, habitat preservation and breeding programs, leading to a successful recovery of the species.

Benjamin Franklin famously got his feathers ruffled when the Second Continental Congress selected the bald eagle to symbolize the fledgling United States. In a letter to his daughter, Franklin charged that the eagle has a "bad moral character" because it lazily steals food from hawks and is easily frightened when approached by smaller birds [source: Franklin Institute]. Instead, Franklin wanted to substitute the turkey, despite it being "a little vain and silly." At least, he reasoned, the gobbler displayed courage by procuring its own dinner.

Franklin was correct regarding the bald eagles' cafeteria-bullying habits. The birds usually nest near freshwater sources, such as rivers and lakes. While they'll go fishing on their own some of the time, a majority of their diet comes from foraging carrion and snatching meat away from other animals [source: National Geographic]. Eagles prefer fish, but will also eat waterfowl and small mammals on occasion.

In 1782, when the eagle ascended to its position as the national symbol, around 100,000 nesting pairs lived throughout the United States in habitats ranging from Alaska to northern Mexico. By 1963, the U.S. Fish and Wildlife Service estimated that only 417 nesting pairs remained in the lower 48 states. The government's efforts to protect the dwindling avian species began in 1940 with the passage of the Bald Eagle Protection Act, which made it a crime to take or sell the eagles. But it would take 40 years of concerted bald eagle conservation efforts to usher the species back from the brink of extinction.

Bald Eagle Recovery

As people settled throughout the Western half of the United States, some bald eagle habitats were destroyed in the process. Eagles prefer not to live near humans, instead selecting tall, mature trees near water for nesting. Because the bird of prey's diet may include livestock such as chicken and lamb, some farmers and ranchers hunted bald eagles to protect their farms [source: U.S. Fish and Wildlife Service].

The bald eagle (Haliaeetus leucocephalus) population received the biggest blow from the environmental prevalence of a chemical pesticide called Dichloro-diphenyl-trichlorethane (DDT), which seeped into freshwater supplies. This meant that fish swimming in the polluted waters would absorb the chemical. From there, eagles would ingest the fish and effectively consume the poison. Once in their bloodstreams, DDT caused females to produce eggs with shells too thin to protect the embryo. Since the hatchlings couldn't survive, the number of bald eagles shriveled accordingly. Rachel Carson's 1962 book "Silent Spring" about DDT's harmful environmental effects helped bring about the ban on the pesticide's use in 1972.

In 1967, bald eagles were added to the endangered species list. That designation offered the eagles more habitat protection from development and made it illegal for anyone to kill them. The U.S. Fish and Wildlife Service headed the repopulation efforts through programs like breeding a colony in captivity at the Patuxent Wildlife Research Center in Maryland [source: U.S. Fish and Wildlife Service]. By monitoring the growth of that group of bald eagles and eventually releasing them into the wild, the species began to rebound. The agency divided the country into five regions to manage the revitalization [source: U.S. Fish and Wildlife Service]. Then, in 1995, the government transferred bald eagles in the lower 48 states from endangered to threatened classification. Threatened status means that a species is no longer in immediate danger of extinction but still needs protection.

Although they were designated as threatened, strict rules regarding the eagles' habitats persisted. For instance, the general rule for building around an eagle nesting site is that it can't come within a 330-foot (100-meter) radius [source: Slevin]. That restriction hampered Minnesota resident Edmund Contoski's plans to develop his lakefront property. Frustrated, he filed a federal lawsuit in 2005 challenging the restriction [source: Slevin]. Contoski won his case on the basis that the eagle's population had reached a level where it no longer should be considered threatened, paving the way for the eagle's removal from the endangered species list.

On June 28, 2007, the Interior Department officially declared the bald eagle to be fully recovered and delisted. At that time, an estimated 9,789 breeding pairs lived in the continental United States, representing one of the most dramatic population improvements for an endangered or threatened species [source: U.S. Fish and Wildlife Service]. Major conservationist groups including the National Resources Defense Council and the National Wildlife Federation approved of the motion as a celebration of the conservation efforts. There have been a few setbacks for this bird of prey recently, as Arizona's U.S. District Court reversed the delisting for bald eagles in that region, reclassifying the Sonoran Desert bald eagle as a threatened species [source: U.S. Fish and Wildlife Service]. However, the U.S. Fish and Wildlife Service maintains protectionist policies to help ensure that the remaining bald eagle population doesn't plummet.

Bald Eagle Recovery Timeline

">1940: Congress passes the Bald Eagle Protection Act.
1962: Congress later amends the act to include the golden eagle, renaming it the Bald Eagle and Golden Eagle Protection Act.
1963: The U.S. Fish and Wildlife Service estimates 417 bald eagle nesting pairs are left in the lower 48 states.
1967: The government declares bald eagles south of the 40th parallel endangered.
1972: The United States bans the pesticide DDT.
1995: Bald eagles in the lower 48 states are moved from endangered status to threatened status.
2007: The government formally removes bald eagles from the endangered species list. However, conservationists later classify the Sonoran Desert bald eagle as threatened in 2008.

Frequently Asked Questions

How did the banning of DDT impact the bald eagle population?

The banning of DDT in 1972 was crucial for the recovery of the bald eagle population. DDT caused eggshell thinning, which led to reproductive failures. With its ban, eagle reproduction rates improved significantly.

What are the ongoing threats to bald eagles despite their recovery?

Despite their recovery, bald eagles face ongoing threats from habitat destruction, lead poisoning from ingesting hunter-shot lead bullets, and collisions with vehicles and power lines.

Lots More Information

Bald Eagle Size, Diet and History as a National Icon

By: Patty Rasmussen | Updated: Jun 24, 2024

If you're a young nation selecting a national bird, you could do a lot worse than the bald eagle. It's got the unforgettable profile, the steely-eyed gaze, the dramatic white and brown coloring and awesome wingspan. And when you factor together bald eagle size, range and natural majesty, it seems like an easy choice for a national symbol.

At least that's probably what members of U.S. Congress thought in 1789 when the bald eagle was chosen to represent the fledgling nation.

To get the scoop on bald eagles, we talked to Scott Courdin, wildlife curator at the Center for Wildlife Education and the Lamar Q. Ball, Jr. Raptor Center at Georgia Southern University in Statesboro, Georgia. Courdin is an expert falconer and manages the center's menagerie, which includes two bald eagles.

Contents

A 6- to 7-Foot Wingspan Is Typical
Bald(e) Is Beautiful
Bald Eagles Chow Mostly on Fish
Bald Eagles: Scavengers and Hunters
A Wide-ranging Bird
Bald Eagles Mean It When They Say 'I Do'
Bald Eagles Only Lay One Clutch of Eggs Per Year
Their Nests Are Huge
A Bald Eagle Will Hold a Grudge
The Turkey Could Have Been the U.S. National Bird

A 6- to 7-Foot Wingspan Is Typical

Female bald eagles are larger than males, and can weigh anywhere from 10 to 14 pounds (4.5 to 6.3 kilograms). Her wingspan will be between 6 to 7 feet (1.8 to 2.1 meters) The male bald eagle is smaller, at around 9 to 10 pounds (4 to 4.5 kilograms). His wingspan is about 5.5 to 6 feet (1.6 to 1.8 meters).

While the bald eagle's size is indeed impressive, they aren't the only North American bird with an impressive wingspan. The golden eagle, for example, is commonly measured as being about on par with the bald eagle's wingspan, at about 6 to 7 feet (1.8 to 2.1 meters).

The California condor, on the other hand, easily bests the bald eagle in terms of wingspan. Adult specimens can easily reach 9 to 10 feet (2.7 to 3 meters).

Bald(e) Is Beautiful

The adult bald eagle doesn't have the "bald" moniker because his scalp looks hairless, but because it's white. Its name comes from the Middle English word "balde" which means "white."

In fact, adult bald eagles don't even develop their striking white head and tail feathers until they are mature, somewhere between 4 and 5 years old.

The young birds don't usually attain adult plumage until their fifth year. Instead of the adult bald eagle's white head and neck, the immature bald eagles are mostly dark brown, with mottled brown and white wings.

Bald Eagles Chow Mostly on Fish

So, what else do bald eagles eat? Mostly fish, waterfowl and other small game like rabbits, squirrels or rodents. They require a pretty wide hunting territory, about 25 miles (40 kilometers). A 6-pound (2.7 kilogram) eagle (which is about average) can live off two adult rats easily.

"That's a daily feed," says Courdin. "But most birds don't eat every day because they will catch something that's large enough to sustain them for a couple of days. Instead, they might feed off something large and fill their crop, a part of their digestive system where they temporarily store food that can sustain them for two or three days. Sometimes even longer."

Bald Eagles: Scavengers and Hunters

Since they are a type of sea eagle, this preponderance of fish in the bald eagle's diet is easy to understand.

Bald eagles are considered opportunistic carnivores, which means that they usually eat whatever is available. That includes dead fish that have washed up on shore, or even stealing from other birds such as ospreys.

This type of food-snatching behavior has a specific name, and not a very nice one: "kleptoparasitism." But it's more common among the immature birds. Once mature, bald eagles can be formidable hunters when necessary. When a bald eagle swoops down to catch its prey, it uses its razor-sharp talons to snatch the unlucky animal it has decided to make a meal out of.

A Wide-ranging Bird

Bald eagles are the only sea eagles endemic to North America, and they really have the territory covered. The bald eagle's range stretches from Southern Alaska to Northern Mexico, and from coast to coast.

Due to their distinctive plumage, they are almost impossible to mistake with other birds, even other large eagles.

Therefore, unlike other raptors (such as the red-tailed hawk), you don't have to consider whether you're looking at a bald eagle, a white-tailed eagle, Steller's sea eagle or any of the other largest eagles in the world. When you see that white head soaring above the trees, it's a bald eagle for sure.

Bald Eagles Mean It When They Say 'I Do'

Bald eagles mate for life. If one mate dies, the remaining bird may take a new mate. Mates build nests, or aeries, together, which takes about one to three months. They also trade parental duties, with each adult bird taking their turn sitting on the eggs (although the females tend to do this more).

Bald Eagles Only Lay One Clutch of Eggs Per Year

Because it takes 10 to 12 weeks for eagles to grow and fledge (take their first flight), eagles lay only one clutch (or group of eggs) per year. Both parents share incubation duties (35 days).

"If their eggs or their young are destroyed early enough in the season, they will lay another clutch to try to reproduce again," Courdin says. "In fact, that's part of how they got the (bald) eagle population back up. They would remove eagle eggs from the nest early in the season and the adult eagle would lay another set of eggs. It's called a 'double clutch.'"

Their Nests Are Huge

Bald eagles have the largest nest of any bird species in North America.The average nest size is 4 to 5 feet (1.2 to 1.5 meters) in diameter and 2 to 4 feet (0.5 to 1.2 meters) deep. The biggest aerie on record was built by a pair of bald eagles in St. Petersburg, Florida. It was 9 feet (2.9 meters) wide, 20 feet (6 meters) deep and weighed 2 tons (1.8 metric tons).

"Eagles only live in their nest during the mating season, incubation and while they're raising the fledglings," says Courdin. "Once they learn to fly and everyone is out, they don't live in the nest."

These nest-building champs return to the same nest year after year, if possible, but will leave if the tree it's built in can't sustain it.

A Bald Eagle Will Hold a Grudge

Courdin has worked with many raptors but says bald eagles are unique.

"They tend to never forget anything and they hold grudges," he adds. "If you're training an eagle and you make a mistake, that can either ruin the training you've done or set you back several months." Courdin said it took five years to train Freedom, the male bald eagle trained at the Raptor Center.

The Turkey Could Have Been the U.S. National Bird

Believe it or not, Founding Father Benjamin Franklin favored the turkey as the national bird, instead of the bald eagle, calling it more "respectable," and "withal a true, original native of America."

Courdin says part of Franklin's beef was that the bald eagle is a scavenger. "Which they are," he adds. "Of all the birds of prey other than vultures, bald eagles will most readily go to a dead animal on the side of the road where other birds of prey will only eat carrion if they are starving."

Nevertheless, the bald eagle was chosen as a symbol of strength, courage and freedom. And despite Franklin's comments, the bald eagle is indigenous only to North America (unlike other eagle species).

The Tiny Fox Saved From the Brink of Extinction

By: Christopher Hassiotis

Island Fox Announcement Video U.S. Fish and Wildlife Service

We've grown accustomed to a certain type of sad news cycle: One year you hear a species is endangered, and soon after, there's another announcement that the endangered animal's gone extinct. That makes it all the more important to celebrate the success stories in wildlife preservation, and the newest one involves one of the rarest mammals in the United States: a tiny fox no larger than a housecat that weighs only 4 pounds (1.8 kilograms) when fully grown.

Four of the six Channel Islands off the coast of Southern California have been home to the island fox (Urocyon littoralis). Starting In the late 1990s, the island fox population on Santa Cruz plummeted in the span of a decade by 95 percent, from 3,600 to fewer than 100 animals on all the islands combined. Subsequent to that near-total collapse, all four subspecies of island fox living on the Channel Islands were placed on the endangered species list in 2004. But thanks to recent efforts by government and private organizations, more than 2,000 foxes now live on Santa Cruz alone, up from 55 in 2004.

"It's remarkable to think that in 2004, these foxes were given a 50 percent chance of going extinct in the next decade. Yet here we are today, declaring three of the four subspecies recovered and the fourth on its way," said National Park Service director Dan Ashe in a press release.

A combination of factors contributed to the near-extinction. In the mid-19th century, ranchers brought pigs to the islands. Over the past 160 years the pig population ran wild, damaging the ecosystem and disrupting the island's food chain — the pigs trampled the habitats of the animals the foxes would eat. Additionally, the pig population attracted golden eagles from the mainland, and those predatory birds would hunt baby foxes. The golden eagles didn't live on the islands originally, but filled a niche after the bald eagle population was destroyed by the pesticide DDT. The bald eagles that lived on the islands primarily ate marine animals and posed no threat to the foxes, but the golden eagle diet includes rodents and small mammals.

The feral pig population peaked at more than 5,000 animals before conservationists intervened. Ecologists had to restructure the entire ecosystem to save the foxes. The National Park Service, the Nature Conservancy, Santa Catalina Island Conservancy and Institute for Wildlife Studies joined forces to bring the foxes back from the brink, establishing a captive breeding program. A team of hunters were brought in to capture or kill the pigs, and scientists captured golden eagles on the islands and returned them to the mainland.

"The fact that they're isolated on these islands gives them a unique personality," says Christina Boser, a scientist with the Nature Conservancy, in the above Wired video. "They're very curious."

The foxes of San Miguel, Santa Rosa and Santa Cruz, the most biodiverse island in California, have been removed from the endangered species list and listed as fully recovered, while the Santa Catalina subspecies shifted from endangered to threatened and may soon join its cousins.

"It's an exceptional success to be able to take a species off the endangered species list," says Boser, "particularly the fox. It's the fastest mammal recovery in the history of the Endangered Species Act."

How the foxes reached the islands in the first place isn't clear, though scientists point to evidence that some may have swam or floated to the islands thousands of years ago. Additionally, indigenous tribespeople transported the foxes from at least some of the islands to others as traveling companions.

But just because the island fox population is on the rebound these days, that doesn't mean life's trouble free. The population is still fragile, and researchers caution that the biggest threat to the little canids still lurks only a few miles away — mainland diseases not yet on the island could spell trouble for the fox population.