Jul 03

Bald Eagles: Our National Bird in Yellowstone

Bald eagle perchedIf someone calls you “eagle-eyed,” consider it the highest of compliments. Eagles are capable of seeing fish in the water from several hundred feet above, and land prey the size of a rabbit at more than three miles away. This is just one of the super powers that has gained the eagle an important role in legend and symbolism throughout human history.

The bald eagle (Haliaeetus leucocephalus)—native only to North America—was chosen by Congress for the United States’ official seal in 1782, bestowing the status of both national bird and national symbol. The majestic bird of prey was thought to represent the fledgling nation’s values of independence and freedom, and more recently has also become a symbol of resilience.

Comeback Story
In the late 1800s, the U.S. was home to 100,000 nesting bald eagles, but that number gradually decreased due to hunting, habitat destruction, and growing pesticide use. By the 1960s there were only around 400 breeding pairs left in the lower 48 states.

Thanks to placement on the Endangered Species List in 1978, along with stricter restrictions on the pesticide DDT, our national bird rebounded and the species was delisted in 2007. There are now an estimated 5,000 nesting pairs in the contiguous United States, from sea to shining sea. Several of these magnificent raptors make their home in Yellowstone National Park.

The Life of a Bald Eagle
Bald eagle pair, Yellowstone LakeEagles form long-term pair bonds and co-parent their young. During breeding season, the male and female work together to build a nest of sticks, or they may reuse their nest from the previous year. After the female lays one to three eggs (usually two), both adults incubate the eggs, which hatch in around 35 days.

At birth, the downy eaglets are immobile and completely dependent upon their parents for food, but they are ready to fly from the nest at 10–14 weeks old. Immature bald eagles show varying amounts of white so they may be mistaken for golden eagles until they develop their recognizable white heads and tails at four or five years of age. Bald eagles that make it to adulthood can live an average of 20-30 years in the wild.

The swift hunters glide through the air at around 40 miles (64 kilometers) per hour, and when they spot their prey, they can dive down at speeds of up to 100 miles (161 kilometers) per hour. They use their sharp talons to grab their prey and, with an extremely powerful grip, they can carry fish or animals up to one-third of their body weight.

Catching sight of the bald eagle in flight is sure to inspire awe, for both their grace and their impressive size. Their bodies can be three feet (one meter) long, and their wingspan can be an astonishing eight feet (2.4 meters) across.

Bald Eagles in Yellowstone
Bald Eagle fishing on Yellowstone LakeWhile the number of resident bald eagles in Yellowstone is unknown, in 2016 biologists monitored 14 known active nests, so it’s believed there are at least that many nesting pairs in the park. They occupy territories near the park’s major rivers and lakes, where they feed primarily on fish, but also on waterfowl and carrion.

Most adult eagles in Yellowstone are year-round residents, but even these hardy birds can be challenged by the park’s extreme climate. Some young migrate in fall to the west coast, and some adults return to their nesting sites by late winter. In severe winters, eagles may move to lower elevations such as Paradise Valley, north of the park, where food is more available.

Where to See Bald Eagles
Bald Eagle on alert, Paradise Valley
Hayden Valley and along the Madison River are among the best places to see bald eagles year-round in Yellowstone. In the summer, watch for them around Yellowstone Lake, and in the winter you may see them near the Gardner River in the northwestern part of the park. Look for their large nests atop tall trees, and scan the skies nearby.

On your next visit, while you’re busy scouring the landscape for a glimpse of bison, wolves, or bears, don’t forget to look skyward for a chance to see our spectacular national bird in flight.

By Christine Gianas Weinheimer 
Photos, top to bottom: Bald eagle over Yellowstone Lake – NPS/Jacob W. Frank; Bald eagle perched – NPS/Neal Herbert; Bald eagle in flight, Gardiner – YF/Matt Ludin; Bald eagle pair, Yellowstone Lake – YF/Matt Ludin; Bald Eagle fishing on Yellowstone Lake – NPS/Jacob W. Frank; Bald eagle on alert, Paradise Valley – YF/Matt Ludin.