12 Fascinating Facts About Bald Eagles
Did you know bald eagles build some of the largest of all bird nests - including one as big as 10 feet wide and 20 feet tall? Discover more intriguing facts about these grand raptors...
STORY AT-A-GLANCE
A juvenile bald eagle who was deliberately shot with a rifle while perched in a tree last fall, spent the winter at Washington State University's Stauber Raptor Facility healing from his wounds
As spring and his eventual release approached, the young eagle's WSU caretakers took him for regular tethered flights to improve his physical conditioning
While the bald eagle was able to return to the wild, not every raptor is so lucky; Amicus, a golden eagle who's been at the Stauber facility since 2006 must remain in captivity after being blinded, possibly because of lead poisoning, another significant threat to raptors
In the fall of last year, a juvenile bald eagle was brought to Washington State University's College of Veterinary Medicine with a broken wing. The male bird, estimated to be about 1½ years old, arrived at WSU's Stauber Raptor Facility in late October 2021 from the Kettle River Raptor Center in Kettle Falls, WA.
Sadly, the raptor's injuries appeared to have been the result of someone aiming a rifle into the tree he was perched in and firing straight up. The bullet entered the eagle's wing, fracturing the ulna, and fragments traveled up through the shoulder, causing damage to that area as well.
WSU professor Marcie Logsdon told The Lewiston Tribune that the act of shooting the bird was "very, very illegal" (not to mention heinous and heartless), because bald eagles are protected under the Bald and Golden Eagle Protection and Migratory Bird Treaty acts.1 The shooting was reported to the U.S. Fish and Wildlife Service.
Eagle Enters Raptor Rehab
WSU's Raptor Rehabilitation Program treats around 150 raptors each year, and there are typically 6 to 12 eagles among them. Some injuries are the result of collisions with vehicles, but a growing problem is lead poisoning. In fact, every eagle who arrives receives a blood test to check for lead.
As both hunters and scavengers, bald and golden eagles often feast on the remains of animals killed by human hunters — "gut piles" that often contain spent ammunition. "There are nontoxic options available for ammunition," says Logsdon, but they've been slow to catch on.
The young bald eagle who appeared to have been shot deliberately was badly injured, but thankfully, the bullet missed vital structures. Wound management included wrapping the wing to immobilize it while nature went to work knitting the bone back together. The bird healed relatively quickly, but his WSU caregivers decided to keep him confined during the winter months and release him as spring approached.
To prepare the eagle for his return to the wild, his caregivers employed a technique called "creancing" that allows the bird to fly while tethered to a long lead. A typical creancing regimen is two to three sessions a week, for two to four weeks, with about 15 flights per session.
"The purpose is physical conditioning," Logsdon explained. "They tend to improve very, very quickly."
Tethered Practice Flights Lead to Freedom
As the date for his release approached, the young eagle's caregivers took him frequently to the Rogers-Orton Playfield on the WSU campus for practice flights during which he was attached to about 200 feet of rope.
Logsdon coached members of the caregiver team, including veterinary students, on how to release the eagle with some forward momentum, essentially "throwing" the bird forward in an intentional way.
While bald eagles look like rather enormous birds, they weigh "about the same amount as your average house cat," according to Logsdon, and this one tipped the scales at about 7 pounds.
For his part, the young raptor didn't seem to mind being handled by an assortment of humans, perhaps in part because, according to Logsdon, male bald eagles are a bit more docile than females.
In early March, the raptor was transported to an area near where he was found in Ferry County, WA and released back into the wild.
Not Every Rehabbed Raptor Can Return to the Wild
Unlike the young bald eagle, not every rehabbed raptor can return to the wild. One example is Amicus (Latin for "friend" or "comrade"), a golden eagle who's been at the Stauber facility since 2006. Amicus was found as a fledgling and is now about 7 pounds.
Sadly, Amicus is blind, possibly from lead poisoning. No one knows for certain. As a permanent resident of the facility, Amicus is an ambassador of sorts who spends time familiarizing and educating the public about raptors. "He enjoys getting out and about," says his primary caregiver, first-year veterinary student Lillian Zachary.
12 Fascinating Facts About Bald Eagles
From the National Park Service:2
The bald eagle is one of the largest birds of prey (raptors) in North America.
The bald eagle's natural range covers most of North America, including most of Canada, the entire continental U.S., and northern Mexico. It is the only sea eagle endemic to North America.
As a result of persecution by humans and the effects of organochlorine chemicals such as DDT, breeding bald eagles were eliminated by the mid-1950's. However, an innovative reintroduction program conducted in 2002 and 2006 produced 61 young bald eagles that were released on the northern Channel Islands. Bald eagles have also been reintroduced on Santa Catalina Island.
At minimum population, in the 1950s, the bald eagle was largely restricted to Alaska, the Aleutian Islands, northern and eastern Canada, and Florida. It presently occupies historical habitats from the bayous of Louisiana to the Sonoran Desert and the eastern deciduous forests of Quebec and New England. Northern eagles are migratory, while southern birds are resident, remaining on their breeding territory all year.
Rather than fish for themselves, bald eagles are known to poach the catch of others. For example, a bald eagle will harass a hunting osprey until the smaller raptor drops its prey in midair, allowing the eagle to catch it and claim it for his own.
Bald eagles have been reported to hunt cooperatively, with one bird flushing prey towards their partner.
Bald eagles build some of the largest of all bird nests — typically 5 to 6 feet in diameter and 2 to 4 feet tall and ranging in shape from cylindrical to conical to flat, depending on the supporting tree.
The largest bald eagle nest on record was discovered in St. Petersburg, Florida. The mega-nest was 10 feet in diameter and 20 feet tall. Another famous nest in Vermilion, Ohio was reportedly shaped like a wine glass and weighed over 2 tons. It was used for 34 years until the tree that housed it blew down.
Young bald eagles spend the first years of life exploring vast territories and can fly hundreds of miles per day. Some young eagles from California have reached Alaska.
Bald eagles can have long lifespans, with a longevity record of 28 years in the wild and 36 years in captivity.
The bald eagle prefers old-growth and mature stands of coniferous or hardwood trees for perching, roosting, and nesting. Selected trees must have good visibility, an open structure, and proximity to prey, but the height or species of tree is not as important as being near water. The bald eagle is extremely sensitive to human activity and is found most often in areas free of human disturbance.
Male and female bald eagles are identical in plumage coloration, but like many other raptors, females are 25% larger than males.
Healthypets Disclaimer: This information is for educational purposes only and is not intended to replace the advice of your own veterinarian or doctor. Dr. Karen Becker cannot answer specific questions about your pet's medical issues or make medical recommendations for your pet without first establishing a veterinarian-client-patient relationship. Your pet's medical protocol should be given by your holistic veterinarian.