Large, powerful, predatory eagles are active in the daytime. Eagles differ from other carnivorous birds in large sizes, powerful physique and massive head and beak. Even the smallest members of the family, such as the dwarf eagle , have relatively long and evenly wide wings.
Most species of eagles live in Eurasia and Africa. Bald eagles and golden eagles live in the USA and Canada, nine species are endemic to Central and South America and three to Australia.
The eagle resembles a vulture in body structure and flight characteristics, but it has a fully feathered (often crested) head and strong legs with large curved claws. There are about 59 different species of eagles. Ornithologists divided the eagles into four groups:
- eating fish;
- eating snakes;
- harpy eagles - prey on large mammals;
- dwarf eagles eat small mammals.
Female eagles are larger than males by as much as 30%. The life span of an eagle depends on the species; a bald eagle and golden eagle live for 30 years or more.
Physical features of the eagle
Almost all eagles are spindle-shaped, which means that the bodies are rounded and taper at both ends. This form reduces drag in flight.
One of the most striking features of the eagle is its heavy curved bone beak, which is covered with keratin horn plates. The hook on the tip tears apart the flesh. The beak is sharp along the edges, cuts the hard skin of the prey.
Eagles have two ear holes, one behind, the other under the eye. They are not visible, as they are covered with feathers.
The wings are long and wide, which makes them effective for soaring flight. To reduce turbulence during the passage of air through the end of the wing, the tips of the feathers at the end of the wings are narrowed. When the eagle fully expands its wings, the tips of the feathers do not touch.
Organs of vision of the eagle
The keen vision of an eagle discovers prey from a great distance. The eyes are located on both sides of the head, directed forward. Large pupils provide minimum visual acuity, which minimally scatter the light entering the pupil.
The eyes are protected by the upper, lower eyelids and migratory membranes. It acts like a third eyelid, moves horizontally, starting from the inner corner of the eye. The eagle closes the transparent membrane, protects the eyes without loss of vision. The membrane distributes the eye fluid while retaining moisture. It also protects when flying on windy days or when dust and debris are in the air.
Most eagles have a protrusion or eyebrow above and in front of the eye, which protects from the sun.
Eagles have muscular and strong legs. Paws and feet are covered with scales. There are 4 fingers on the paw. The first is directed back, and the other three are forward. Each finger has a claw. The claws are made of keratin, a hard fiber protein and curved down. With strong fingers and strong sharp claws, birds catch and carry prey.
Eagles, which kill and carry large prey, have long hind claws, which also catch other birds in flight.
Most species of eagles have plumage of not very bright colors, mainly brown, rusty, black, white, bluish and gray. Many species change the shade of plumage depending on the stage of life. Young bald eagles are completely brown in color, and adult birds have a characteristic white head and tail.
The most common types of eagles
Golden Eagle (Aquila chrysaetos)
Mature golden eagles are pale brown with golden heads and necks. Their wings and lower body are dark grayish-brown, the bases of the wing and tail feathers are marked by fuzzy darker and paler stripes. The golden eagles have pale reddish-brown spots on the chest, on the front edges of the wings and on the central lower parts of the body. Whitish spots of different sizes are visible near the joints on large central and internal hidden feathers of the wings.
The plumage of young golden eagles is characterized by greater color contrast. The feathers of the wings are dark gray, without stripes. Whitish spots are visible on the main and some secondary feathers closer to the bases, and the upper and lower covering plumage of the wings are blackish-brown. The tails are mostly white with a wide black stripe along the tips.
Adolescents gradually change color and begin to look more like adult birds, but get full plumage of adult golden eagles only after the fifth molt. Reddish marks on the stomach and back are more pronounced with age. Golden eagles have yellow claws and feathers on the upper part of their paws and blackish beaks with yellow wax. In young birds, irises are brown, in mature ones they are yellowish-red.
Golden eagles fly, making 6–8 wing flaps, followed by planning, lasting several seconds. Soaring golden eagles lift their long wings up in a light V-shape.
Hawk Eagle (Aquila fasciata)
While searching for food, birds display a unique feather pattern. The hawk eagle has a dark brown color on the upper part, white on the stomach. Elongated vertical dark stripes with a noticeable pattern are visible, which gives the eagle a characteristic and beautiful appearance. The eagle has a long tail, brown above and white below with one wide black end stripe. Its paws and eyes are distinctly yellow, and a light yellow color is visible around the beak. Young eagles are distinguished from adults by a less bright plumage, a beige belly and the absence of a black strip on the tail.
In a graceful flight, the bird shows strength. The hawk eagle is considered a bird of small and medium size, but its body length is 65-72 cm, the wingspan for males is about 150-160 cm, for females - 165-180 cm, this is really impressive. Weight ranges from 1.6 to 2.5 kg. Life expectancy up to 30 years.
Stone Eagle (Aquila rapax)
In birds, the color of plumage can be anything from white to tan. These are predators versatile in terms of nutrition, they eat anyone from dead elephants to termites. They prefer to delve into the garbage and steal food from other predators when they can, and hunt when there is no carrion nearby. The habit of collecting garbage negatively affects the population of stone eagles, because they often eat poisoned baits used by humans in the fight against predators.
Stone eagles are far more effective at eating than their mammalian counterparts, as they see carcasses earlier and fly up to potential food faster than a land animal reaches.
Steppe Eagle (Aquila nipalensis)
The call of the steppe eagle sounds like a cry of a raven, but it is rather a quiet bird. The length of the adult is about 62 - 81 cm, the wingspan is 1.65 - 2.15 m. Females weighing 2.3 - 4.9 kg are slightly larger than 2 - 3.5 kg of males. This is a large eagle with a pale throat, brown upper body, blackish flight feathers and tail. Young birds in color are less contrasted than adults. Eastern subspecies A. n. nipalensis is larger and darker than European and Central Asian A. n.
This is one of the largest eagles, it is slightly smaller than a golden eagle. Body size from 72 to 84 cm, wingspan - from 180 to 215 cm. Adult birds are dark brown, almost black, with a characteristic golden color on the back of the head and neck. Usually on the shoulders there are two white spots of different sizes, which some individuals are completely absent. Tail feathers are yellowish gray.
Young birds have ocher-colored feathers. The flying feathers of young burial eagles are uniformly dark. The color of an adult is formed only after the 6th year of life.
A subspecies with dark plumage is less common. Head and neck pale brown, veins dark brown. The forehead is white. The upper body is dark brown with lighter feathers on the upper half of pale ocher, with dark grayish-brown edges of the tail. The lower body is black-brown.
At the light subspecies of the dwarf eagle, white feathers are visible on the legs. The back is dark gray. The lower body is white with reddish-brown streaks. The head is pale red and streaked. In flight, a pale band is visible on the dark upper wing. The winged pale with black feathers.
Both sexes are similar. Young individuals resemble adults of a dark subspecies with a ginger lower body and dark stripes. The head is reddish.
Silver Eagle (Aquila wahlbergi)
This is one of the smallest eagles, and is often confused with the yellow-billed kite. The individuals are mostly brown, but several different color morphs within the species have been recorded, some birds are dark brown, others are white.
A nimble silver eagle preys in flight, rarely from an ambush. It attacks small hares, young guinea fowl, reptiles, insects, steals from nests of chicks. Unlike other eagles, whose chicks are white, the young of this species is covered with chocolate brown or pale brown fluff.
Kaffir Eagle (Aquila verreauxii)
One of the largest eagles, 75–96 cm in length, males weigh from 3 to 4 kg, more massive females from 3 to 5.8 kg. Wingspan from 1.81 to 2.3 m, tail length from 27 to 36 cm, foot length - from 9.5 to 11 cm.
The plumage of adult eagles is dark black, with a yellowish head, beak gray and yellow. Intensively yellow “eyebrows” and rings around the eyes contrast with black feathers, and irises are dark brown.
The eagle has a V-shaped snow-white pattern on its back, the tail plumage is white. The pattern is noticeable only in flight, because when the bird sits, white accents are partially covered by wings.
The wing bases are decorated with black and white stripes, the beak is thick and strong, the head is round, the neck is strong, long legs are fully feathered. Teenage eagles have a golden-reddish head and neck, a black head and chest, cream-colored paws, covering wings with a dull yellow color. The rings around the eyes are darker than in adult eagles, acquire the color of a mature individual after 5-6 years.
How do eagles breed?
They build nests on tall trees, rocks and cliffs. The female lays a clutch of 2-4 eggs and incubates them for about 40 days. Depending on the climate, incubation lasts from 30 to 50 days. The male catches small mammals, feeds the eagle.
After leaving the egg covered in white fluff, the helpless cub is completely dependent on the mother for food. It weighs about 85 grams. The first cub has an advantage in age and size over other chicks. It grows faster and competes more successfully for food.
Before leaving the nest for the first time, young eagles remain “chicks” for 10-12 weeks. It takes so long for the chicks to be feathered enough to fly, and large enough to hunt prey. The young individual returns to its parent nest for another month and asks for food as long as it is fed. 120 days after birth, the young eagle will become completely independent.
Who are the eagles hunting for?
All eagles are strong predators, but the type of feed depends on where they live and on the species. Eagles in Africa mainly eat snakes, in North America fish and waterfowls such as ducks. Most eagles prey only on prey, which is smaller than them, but some eagles attack deer or other large animals.
Eagles are found in various ranges. These include forests, wetlands, lakes, meadows and more. Birds live almost everywhere in the world except Antarctica and New Zealand.
Who hunts eagles in nature
A healthy adult eagle, thanks to its impressive size and hunting skill, has no natural enemies. A number of predators prey on eggs, chicks, young eagles, and wounded birds, such as other birds of prey, including eagles and hawks, bears, wolves, and cougars.
Habitat destruction is one of the biggest threats. The territory of birds, as a rule, extends to 100 square km, and they return to the same nest from year to year.
Eagles are chased by people for hunting livestock or killing game such as hazel grouse. Many eagles were indirectly poisoned by carrion, which in turn died from pesticides.
In some regions, birds are hunted for feathers, eggs are stolen for illegal sale on the black market.
Interesting facts about eagles - video