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Being an avid bird watcher, some of my favorite moments in life have been up at camp in Maine, canoeing to the small lake islands that were home to giant Bald Eagle’s nests.
Towering rugged trees with sprouts of pine needles and limbs stretching to the clouds held colossal nests of branches, sticks, and soft grasses in their uppermost boughs. Craggy promontories with rough-hewn boulders sporting patches of moss surrounded the edges of the small isles.
Quiet as mice, we would be (although mice would not have been so safe), ever so slightly moving our arms as we drifted closer to the great watcher and protector’s lair.
Binoculars around our neck, we almost didn’t dare lift our heads and raise our eyes to directly look at this majestic creature, so in awe were we. As we sat there rocking gently in our canoe, if the male or female (both tend to the nest) left the nest and spread their giant wings, swooping and descending, my sister and I would duck as it seemed we were trespassing upon this flying dinosaur’s territory.
The Audobon site’s picture above of the Bald Eagle doesn’t do this living emblem of the United States justice.
Is the Bald Eagle a Dinosaur?
Current fossil evidence is increasingly reinforcing what scientists have thought for decades, that birds have origins in bird-like dinosaurs called maniraptorans.
Palate structure, skull openings, and even leg and foot structures are some of the shared traits between birds and dinosaurs.
A recent finding shocked the scientific community when they found a fossil of a maniraptor sitting on its eggs, just like a bird! These parental skills for incubation were present through DNA and hormones even in the Cretaceous period!
For those of us who want to get official, there is a list of proper names below:
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Accipitriformes |
| Family: | Accipitridae |
| Genus: | Haliaeetus |
| Species: |
H. leucocephalus
|
Bald Eagles as Predators, Scavengers, Skilled Hunters, and Thieves
Our great nation almost didn’t have the Bald Eagle as its national symbol. Benjamin Franklin thought the bird was “of bad moral character” and wanted Wild Turkey to be our nation’s mascot. If you’ve ever seen this striking raptor on the side of the road, foraging for scraps from an unfortunate animal who met its untimely death crossing the street, the word “majestic” may not come to mind.
Or, if you watch the powerful bird harass a smaller one (that has already hunted and killed its meal) and steal an easy supper, you may scoff at the phrase “skilled hunter.”
Since 1782 this imposing raptor has represented the United States, and for a good reason. Anyone who studies the habits of this bird for any length of time would be hard-pressed not to appreciate its regal talents.
I would call the Bald Eagle opportunistic and say that it can deftly wear many hats. I base this on my decades of watching them, enthralled with their mighty prowess and keen “eagle” eye.
Hundreds of instances come to mind of them swooping down from great heights, eyes fixed on a silvery fish, limbs outstretched toward the water, claws out as they snatch the unwary fish right up and out of the water.
Beating their enormous wings to suspend them in flight, they hover for the briefest of moments before rising again with grace and power to fly back to the nest where they will feed pieces of the fish to their young (typically one to three young ones in a nest).
Bald Eagles are Made for Hunting
Though fish make up more than 56% of a Bald Eagle’s diet, small mammals, reptiles, and carrion are on the menu when fish is not readily available. You may find it a bit surprising to see a Bald Eagle huddled over the carrion of an animal that it did not kill. That seems more like a vulture situation, circling in the air to signify death.
During the hundreds of hours watching this magisterial bird of prey, it seemed to me that most activities of the Bald Eagle centered around the pursuit and capture of food – namely fish. The predominant characteristic of its action was guided by, as the cliche parrots, its “eagle eye.”
Aptly named, having an eagle eye refers to the bird’s ability to have both monocular and binocular vision. Sound familiar? Humans need binoculars, and exceptionally strong ones at that, to see half as far as the Bald Eagle. The Bald Eagle can see something the size of a rabbit three miles away! No wonder it is such a good hunter!
Another inborn trait is the Bald Eagle’s ability to see many more colors than humans and even into the UV spectrum! This skill lets them see urine in water and on land to scout out their prey.
Bald Eagles as Endangered Species
The Bald Eagle came the closest to extinction during the first six decades of the 20th century. Hunting was a popular pastime, and the shooting of the Bald Eagle, as well as land development, decreased their numbers substantially. After being afforded legal protection, however, their numbers continued to drop due to pesticides such as DDT.
Loss of habitat, sport, and manufacturing of toxic chemicals took its toll. It wasn’t until after certain pesticides had been banned that the Bald Eagle population began to rise again slowly, beginning in the 1970s.
In 2007, the Bald Eagle was removed from the national list of endangered species, and many states received recognition for their programs that had fostered the Bald Eagle population.
The U.S. Fish and Wildlife Service still has the Migratory Bird Treaty Act and the Bald and Golden Eagle Protection Act which are laws that prohibit any killing or selling of Bald Eagles or the disruption of their nests or eggs. The FWS has landowner guidelines that foster conservation practices and teach people how to leave Bald Eagle sites undisturbed.
Bald Eagles can live up to 40 years, and the oldest Bald Eagle that was discovered was hit by a car in 2015. It was banded in 1977 and was 38 years old.
Bald Eagle Habitats
I think it is wonderful that Benjamin Franklin didn’t get the Wild Turkey emblem approved for our nation (what does that even say about how he thought of America?).
The Bald Eagle is the only eagle that is native to only the United States and nowhere else! This is our bird! This bird is in all of our states, from Alaska down to the top of Mexico. I think it is very fitting that it signifies the strength of our nation.
Did you know that half the Bald Eagle population in the United States lives in Alaska? Most of them live in the largest volume fishery port in the nation, Dutch Harbor.
A source of plentiful food is needed for Bald Eagles, and since fish is their preferred meal, it is no shock that fishing ports are prime locations. These huge birds like to camp out at lakes, reservoirs, estuaries, large rivers, mountains, forests, and near the ocean. These water-friendly locations with readily available older trees serve to provide drinking water, fishing areas, shelter, and resting areas.
Bald Eagles love to nest on the tops of tall trees (conifers or pine trees being their favorite), and generally nest within 100 miles of where they were born. Scientists have also found Bald Eagle nests on rocks and even on the ground in some uninhabited areas.
Perches are a must-have for Bald Eagles as they look for appropriate breeding grounds. The high perches serve as nesting areas because they are safe and conducive to searching for food and watching their young.
Bald Eagles prefer the tallest trees to house their nests and choose limbs that are heavy and strong. Only mature, old, and dead trees are used, and sometimes a rocky promontory is the most promising area.
Their nests reach up to 10+ feet in diameter and 13 feet deep! That’s more than the average ceiling height! The weight of this nest is gigantic – it can weigh up to 2,000 pounds! The Bald Eagle holds the world’s record of any living creature for a giant tree nest. These raptors build a nest that is built to last because they re-use it every year (sometimes up to 30 years)!
Many Bald Eagles mate for life, and each year the male and female return to their nesting site and begin to strengthen and enlarge the nest for the next crop of young. Depending on the weather or any disasters, this can mean almost building a new nest from scratch. This fortification of the homestead begins up to three months before the female lays the eggs.
The courtship process for the Bald Eagle includes this nest renovation activity and serves to strengthen the male and female Bald Eagle bonds.
A high nest in a tree is referred to as an Aerie. Made mostly of sticks from the ground and tree branches that the Bald Eagle breaks off, the interior “bowl” or round indentation in the middle of the nest (that holds the eggs) is lined with grass, moss, and other soft material that the eagles can find.
The male and female eagles work together to gather sticks near the tree they have chosen for the nest, but the Bald Eagle has been known to carry branches back to the nest from as far away as one mile! That is dedication and parental love!
Interestingly, both the male and female Bald Eagles gather nest materials, but almost all the work of building the nest is done by the female. She intertwines the branches and weaves them together, filling the holes with sod, lichen, plant stalks, or corn stalks.
Threats to the Bald Eagles Nest
Common disrupting factors to the eggs in a Bald Eagle’s nest include raccoons, osprey, owls, and hawks. Other Eagles are threats as well, especially when the food supply is limited in the area. The Male Bald Eagle will defend the nest from other male Bald Eagles, and the females will protect against other female Bald Eagles.
Both will engage when the danger is not a Bald Eagle. Most protection comes in the form of swooping and shrill crying, with a chase ensuing between Bald Eagles. Occasionally, if a persistent predator has been lurking near the nest, the Bald Eagle will engage with talons and beaks, resulting in aerie two-bird somersaults.
Mating and Courtship
Bald Eagles can lay eggs anytime in April and May of every year after they are four years old. In Florida, however, Bald Eagles have been known to lay eggs as early as November due to the influx of other small birds for food sources and the encouraging climate.
The Bald Eagle’s choice of mate is for life as they are monogamous birds. Touching beaks, preening each other and themselves in close proximity to the other all constitute steps in the dance of intimacy. Bald Eagles have also been seen with their mate in mid-air gymnastics, attached at the talons and soaring and diving. As they approach the ground, they let go of each other and steeply fly upwards.
There are two periods of three weeks each during April and May when the female eagle is fertile. The actual mating is done with the male and the female Bald Eagle’s cloaca.
The cloaca (sex organ) is located underneath the birds’ tails. The male Bald Eagle will sit on the back of the female (who has shifted all her tail feathers to one side) and press his cloaca firmly around hers to pass the sperm and fertilize her eggs. The sperm can live and fertilize for about ten days inside the female.
As soon as five to ten days after copulation, the female will lay between one and three eggs, with the rare occurrence being four eggs.
Incubation for the eggs remains close to 35 days, with the first egg hatching then and the rest being hatched at the same time they were laid. In nearly all cases, all of the eggs are hatched within the same 3-6 days. Each baby in the egg cracks its shell without any help from the parents.
The first week after hatching, the male and female remain at the nest (brooding) with the babies for the whole day. The male brings all food to the nest during the first 3 weeks, while the female stays in the nest.
The nest is never left unattended during this 3 week period. During inclement weather, the female spreads her wings over the next to protect the babies from wind, rain, cold and extreme heat. After the sixth week, the parents leave the nest alone for short periods of time.
Both the male and the female tear up the food into small pieces for the birds, gradually increasing the size of the pieces as the chicks grow. After the first few months, the female Bald Eagle will start to bring much more food than the male back to the nest. At two months of age, the young babies can tear up the larger pieces of food themselves.
Survival of the Fittest
Raptors are territorial by nature and can be very aggressive depending upon the food supply and other birds’ penchant to trespass. The same is true with the newly hatched Bald Eagles, who often engage in fighting from the first few days. Again, the food supply is the primary source of contention for Bald Eagles of any age.
The parents will feed twice as much food to the first and biggest hatched baby. Many studies have shown that the first hatched is the biggest and strongest in the nest, with 60% or more of all food brought to the nest being consumed by that one hatchling. That leaves about 15% for the other two siblings and 10% for the parents (who also eat when they are gathering the food).
With this situation being inherently created by the parents, the survival of the young Bald Eagles is, again, dependent upon the food supply. When food is plentiful, and there is more than enough to go around, the first hatched may gain weight faster and get more of the food, but the others have plenty of food to thrive.
When food is scarce, the parents often continue to feed the first youngster 75% or more of the food, while the others may die from aggression from the largest sibling or starvation.
The baby Bald Eagles stay in the nest for about 12 weeks, with the males always being the first to leave the nest. The parents do not teach the young how to fly, and it is built into the DNA for young birds to coordinate their flying abilities automatically.
Many end up on the ground due to falling (after eight weeks), and the parents continue to feed them on the ground until they can become strong enough to fly by themselves.
After learning to fly and leaving the nest, the children are dependent upon their parents for food for another three to four months and will follow their parents everywhere they go to learn how to fish. It is only after much time that the young Bald Eagles will learn to hunt things other than fish by trial and error.
Bald Eagle Description and Colors
Once Bald Eagles reach maturity, it’s easy to tell them apart from other birds by their immense wingspan and bright white head. Until they are about five years old, most people don’t even recognize the juvenile birds as being Bald Eagles due to their overall dark color and mottled white spotting intermittently over their body.
I don’t think I ever mastered the art of distinguishing a juvenile Bald Eagle, and I probably told my dad it was a hawk, heron, osprey, or vulture as he chuckled and explained to me why it was a baby Bald Eagle.
As a fledgling eagle begins to fly, it resembles a large, dark bird of many names.
How Big are Bald Eagles?
Having a wingspan of seven or eight feet and weighing up to 15 pounds, the Bald Eagle can reach a length of almost three feet. Female and male adult Bald Eagles look the same except for their size (the female being about 25% larger than the male). Identifying Bald Eagles that are less than four years of age can be quite difficult as the color variations from birth to four vary considerably.
What Color are Baby Bald Eagles?
Bald Eagle babies will have brown heads until two or three years old when the white will come out in random markings on half of their head. By four years of age, white will be the primary color with only muted brown striations on its head.
At five or six years of age, a bright and pure white head and tail will signal the full adulthood of the Bald Eagle. Adult Bald Eagles have a deep brown body with their head and tail being all white.
Eye Color of Bald Eagles: The iris of their eyes will be dark brown when the Bald Eagle hatches, and through the next four years, their eye color will become lighter brown with golden flecks. At full adulthood, they will have light yellowish-white eyes.
Bald Eagle Beak Color: The beak of the baby Bald Eagle will be grayish-black or dark brown until about three years old when the dark orange rust color will appear and gradually take over. By five or six years of age, the Bald Eagle will have a bright orange/yellow beak, and after age six, the beak remains bright yellow.
Have You Seen a Bald Eagle?
Bald Eagles that have not yet reached their full plumage are often mistaken for other species. Most people have seen young Bald Eagles but just don’t know it because they are looking for the gleaming white head and tail of the adult bird (which they don’t get until they are about six years of age).
People often think they have seen a Golden Eagle or a Turkey Vulture. Though Golden Eagle and Bald Eagle both share the word “eagle”, it doesn’t mean they are closely related. The term “eagle” only signifies a large raptor or a big predator bird.
Things to look for are the 90-degree angle of the wings to the body when the Bald Eagle is in flight.
How Fast Can Bald Eagles Fly?
These creatures are built for speed, and when diving, they can drop at 100 miles per hour! The fastest mammal alive, the cheetah, at 70 mph, can run more than three times the speed of humans! The fastest bird is the Peregrine Falcon which reaches a steep diving speed of 200 mph! Compare this to humans, which have a top running speed of 22 mph, and you can marvel at the wonders of nature!
FAQs
Answer: Bald Eagles have largely nomadic lifestyles that focus on a source of food. Most Bald Eagles prefer not to move far from their breeding grounds, and the migratory path only increases in the distance due to the seasons affecting their food supply.
Baby and juvenile Bald Eagles are especially nomadic after leaving the nest because they have not yet mated and created a nest to have their offspring. Adult Bald Eagles are drawn back to the area where they raised their offspring after leaving in search of more food.
Bald Eagles will, however, move within a certain region (within 100 miles of their breeding ground) to scope out better nesting areas and food supplies.
Answer: The Bald Eagle (from 1 to 4 years old) most frequently gets mistaken as a Golden Eagle because the distinctive bright white head and tail have not yet come into full plumage. This adult feathering happens at five years of age for the Bald Eagle, and you really have to be quite a specialist in the bird-watching field to spot a juvenile Bald Eagle.
In this picture, the left-hand side is the Golden Eagle (fully matured), and the right-hand side is a Bald Eagle who looks to be 2 to 4 years of age. You can see why it is so easy to think you have seen a Golden Eagle!
Answer: Technically, a raptor is a “bird of prey” that uses hunting skills to obtain most of its food. Birds such as the Bald Eagle and the Golden Eagle use their acute visual abilities, cutting hooked beaks ad razor-sharp talons that pick up fish and other small mammals to carry. The Golden Eagle holds the title of the largest hunting bird in North America.
While the California Condor is a larger bird, it is categorized as a “bird of flight” and not a bird of prey. This is for several reasons, including their lack of hunting and pursuing skills, their ineffectual talons, and their only food being already dead (carrion).
Answer: Bald Eagles are excellent swimmers, and even the young babies who don’t know how to fly yet are powerful swimmers. A Bald Eagle will swim back to shore if they have caught a huge fish in their talons that is too heavy for them to lift. They release it and swim back to shore, doing something that looks like the butterfly method.
Check out this video from Lake Winnepesaukee in New Hampshire. They have to swim as their feathers are waterlogged and need to dry before they can fly again. Occasionally a weaker Bald Eagle may drown as it uses up much of the bird’s energy to swim.
In Conclusion
A symbol of the United States that represents survival, strength, courage, and freedom, the Bald Eagle is the most widely recognized bird in the world. Included in the list of items it graces are official documents, currency, flags, passports, and public buildings.
In 1776, a Massachusetts copper one-cent piece held the first Bald Eagle symbol, and in 1782, the Bald Eagle became the national bird of the United States. In 1789, Congress voted to make the Bald Eagle our national emblem, representing our new nation.
The Bald Eagle is a good choice for our nation, as we have clawed and swam our way to democratic shores for hundreds of years. Our determination as a nation to remain free also evokes the powerful stance of the Bald Eagle defending its territory to the last.
One thing I wish we could emulate better is the visual acuity of the Bald Eagle. Seeing four times farther and in more detail than humans, The Bald Eagle has the ability to foresee challenges or opportunities, thus continuing its reign as the mightiest free hunter in the United States. It sure would be nice to have some of that “eagle eye” and put it to use for the nation!
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