Hardware and software complexes orlan, orlan-m, orlan-r. Life story at the Moscow Zoo

Speaking of birds of prey, one cannot but admire their strength, speed, agility and keen eyesight. They soar in the sky over forests, fields, rivers, lakes and seas, striking in their size and power. In addition to appearance, these birds have many advantages, and today we will talk in more detail about one of the representatives of the hawk - eagle.

Eagle appearance

Eagle belongs to the subfamily of buzzards, translated from Greek, its name means sea. Like all members of the species, eagle large bird with a body length of 75-100 centimeters, wingspan up to 2.5 meters and weighing 3-7 kg.

It is noteworthy that the "northern" species are larger than the "southern" ones. Tail and eagle wings wide. Birds have strong legs with sharp curved claws, long (about 15 cm) toes have small outgrowths to make it easier to hold prey, especially slippery fish.

Tarsus is naked, without feathers. The massive beak is crocheted, yellow. Above the sharp-sighted yellow eyes, superciliary arches protrude, because of which it seems that the bird is frowning.

Pictured is a white-tailed eagle

The color of the plumage is predominantly brown, white inserts are located in different species in different ways. May be a white head, shoulders, torso, or tail. Sexual dimorphism is not very pronounced; in a pair, the female can be distinguished by its larger size.

Eagle habitat

These birds of prey are widespread, almost everywhere except Antarctica and South America. 4 types of eagles are found in Russia. The most common is the white-tailed eagle, which lives almost everywhere where there is fresh or salt water. The long-tailed eagle belongs to the steppe species, living mainly from the Caspian to Transbaikalia. Steller's sea eaglefound mainly on the Pacific coast.

Steller's sea eagle pictured

Bald eagle lives in North America, sometimes flying to the Pacific coast, it is considered symbolUSA and is depicted on the coat of arms and other state signs.

In the photo is a bald eagle

The Screamer Eagle lives in southern Africa and is national in some countries there. The largest habitats are located in the lower reaches of the Volga and in the Far East, since these places are rich in fish - the main food for these predators.

All eagles settle near large bodies of water, on the shores of seas, estuaries, rivers, lakes. They try not to fly into the very depths of the land. They rarely migrate, but if the reservoirs in which they get food freeze, then the birds migrate closer to the south for the winter.

Each folded pair has its own territory, which they occupy for years. Usually this is at least 10 hectares of water surface. On their part of the coast, they build a nest, live, feed and breed chicks. Eagles usually spend their hours of rest in a mixed forest.

In the photo, the eagle screamer

The nature and lifestyle of the eagle

This is due not only to a good appetite, but also to the fact that the eagle cannot keep the smaller fish with its long claws. It feeds on a predator and a bird that lives near water bodies -,.

Small mammals are also included in the menu, this,. Various, crustaceans, and others, the eagle can also catch, but they are of much lesser interest to him.

Carrion is also suitable for food, birds do not disdain the bodies of various animals thrown ashore, fish, corpses. In addition, as a large predator, the eagle does not consider it shameful to take away prey from smaller and weaker hunters, or even steal from their own gaping fellows.

The eagle prefers to hunt in shallow water, in those places where there are most fish and it is not difficult to get it. Having noticed the victim, the bird falls down like a stone, grabs the prey and rises into the air with it.

Feathers do not get wet during such a hunt. Sometimes the predator simply walks on the water, pecking small fish from there. But more often the prey is quite large, the eagle is able to hold up to 3 kg. If the weight turns out to be too heavy, the predator can swim with it to the shore, where it will safely dine.

Sometimes a pair of eagles hunt together, especially the larger, faster mammals and birds. One of the predators distracts the prey, and the second suddenly attacks. The eagle can catch smaller birds right in the air. If the prey is large, the predator tries to fly up to it from below and, turning over, pierce the chest with its claws.

The eagle forces waterfowl to dive, circling above them and frightening. When the duck is tired and weak, it will be easy to catch and haul ashore. During the meal, the eagle presses food to tree branches or to the ground with one foot, and with the other and its beak tears off pieces of meat.

Usually, if there are several around, then the more successful hunter tries to retire, because his hungry get together may well force him to share. Large prey lasts for a long time, about one kilogram of food can remain in the goiter, providing the bird for several days.

Reproduction and life expectancy of the eagle

Like other birds of this species, eagles are monogamous. But, if one dies, the second finds her a replacement. The same happens if the "family" is unable to produce offspring. A pair is formed at a young age, this can happen in the spring and during the winter. The breeding season begins in March-April. Eagles in love circle in the sky, claw and dive sharply.

Pictured is the nest of the white-tailed eagle

Having tuned in to the right mood, future parents begin to build a nest, or, if the couple is old, restore last year's. The male provides the female with building materials, which she lays down. Eagle's nest very large, usually about a meter in diameter and up to a ton in weight.

Such a heavy structure is placed by birds on an old, dry tree, or on a freestanding rock. The main thing is that the support should withstand, and various ground predators could not get to the eggs and chicks.

After 1-3 days, the female lays 1-3 white, matte eggs. The mother-to-be incubates the clutch for 34-38 days. The hatched babies are completely helpless, and the parents feed them with thin fibers of meat and fish.

In the photo, the eagle chicks

Usually only the strongest chick survives. After 3 months, the young begin to fly out of the nest, but for another 1-2 months they keep close to their parents. Eagles become sexually mature only by the age of 4 years. But this is normal, considering that these birds live for about 20 years.

Russian name - Bald Eagle

Latin name - Haliaeetus leucocephalus

Squad - falcon

Family - hawk

The bald eagle was recognized as the national bird of the United States in 1782, and since then its image flaunts on the state emblem, presidential standard, banknotes and other government papers and documents.

Conservation status

In the United States, the bald eagle has been protected since 1940. One of two existing subspecies, H.l. leucocephalus (called nominal), is included in the IUCN Red List.

View and person

Despite its "state" status and legislative protection, the number of the bald eagle in the 19th and 20th centuries. decreased sharply. The main reasons for this were mass extermination and human economic activity. The most dangerous for the eagle (as, indeed, for all other species of birds of prey) was the widespread use of DDT and other insecticides, which have a negative effect on breeding productivity (a large number of eggs laid by the eagles died during incubation). The ban on the use of insecticides has led to a gradual recovery in the number of bald eagles, and now its existence in nature is out of danger. The United States currently has laws prohibiting the killing or captivity of live bald eagles without special permission.

For most of the Indian tribes, the bald eagle was considered a sacred bird, an intermediary between earthly people and the heavenly Great Spirit - the creator of the universe. Myths and rituals were dedicated to him, clothes and headdresses were decorated with his feathers. Numerous images of the eagle can still be found on household utensils, dishes, baskets, as well as on totem (sacred) poles and burial grounds.

Spread

The bald eagle lives in Canada, the United States and in some areas in northern Mexico. Its distribution is characterized by extreme unevenness, and the largest number of breeding pairs is concentrated on the sea coasts and near large rivers and lakes.

Until the end of the twentieth century. The bald eagle was occasionally recorded in the Russian Far East, but these were always only occasional flights with no signs of nesting.

Eagle populations living on the sea or ocean coast are sedentary, while populations living along the shores of inland freezing water bodies make regular winter migrations.

Appearance

The bald eagle is one of the largest birds of prey in North America. The total length reaches 70-120 cm, the wingspan is 180-230 cm, the weight is 3-6.3 kg. Females are about ¼ larger than males. Birds living in the northern part of the range are noticeably larger than those living to the south.

The beak is large, hooked, golden yellow in adult birds. The legs are also yellow, and the tarsus and toes are devoid of plumage. The fingers are long, about 15 cm, with sharp claws. The eagle holds the victim with its front fingers, and kills it with the claw of its hind finger.

The color of adult birds looks contrasting and very impressive - a dark brown body and a pure white head. But eagles acquire such an outfit only at the age of 5, approaching adult plumage with each molt. Sexual dimorphism appears only in size.

Feeding and feeding behavior

Of all the available food, the bald eagle prefers fish, both live and dead. In second place in terms of importance are aquatic and near-water birds. With a shortage or inaccessibility of fish, birds can form the basis of food, and their content in the diet of eagles increases from 7-10% to 80%. The predation of eagles is most dangerous for bird colonies, where adult birds, chicks, and eggs become their easy prey. Among mammals, bald eagles can hunt medium-sized land animals, and in some places, seal pups. On average, a bald eagle's diet consists of 56% fish, 28% birds, and 14% mammals.

Activity

Like most birds of prey, eagles are active during the day. (no wonder another name for falconifers is daytime birds of prey).

Vocalization

The voice of the bald eagle is surprisingly weak and low - either a high scream or a whistle. Young birds have a sharper and harsher voice. Adult eagles can be most often heard during the “changing of the guard” at the nest during incubation, as well as in places of mass concentration of birds in winter.

Social behavior

The social behavior of the bald eagle is not very complex and is similar to that of other species of eagle. Their pairs are constant, but outside the nesting period, birds lead a solitary lifestyle. The pair connects only during the nesting period.

During winter migrations, a certain number of eagles may gather in one place, but no strict hierarchy is observed between them.

Reproduction and parenting behavior

The breeding season for bald eagles begins with amazingly beautiful demonstration flights of both birds, during which they chase each other, do deep dives in the air and turn upside down.

Then the couple settles in their nesting area. The protected area around the nest is approximately 1-2 square meters. km, but it can be more or less depending on the number of neighboring pairs and the availability of available production.

Nest construction begins in different states in the United States at different times, from late September to January, but always earlier than other birds of prey in the area. The nest of bald eagles is built of large branches and twigs and is located in the crown of a tall living tree with the possibility of such large birds flying freely and no further than 1-2 km from the water. Among American ornithologists, there is an opinion that the nest of the bald eagle is the largest among all birds in North America: it can reach 2.5 m in diameter and 4 m in height, and weigh about 1 ton. Eagles fasten the main branch frame with grass, dry corn stalks or dry seaweed. Nest construction or renovation takes from several days to 3 months. Both parents participate in this work, but nevertheless, more often the male only brings building material, and the female lays it in the nest. In addition to the main nest, there may be several spare nests on the site of each pair.

Laying takes place 1-3 months after the start of nest construction. The clutch usually contains 2 large light-colored eggs (1 to 3), which are laid at intervals of 1 or 2 days. Incubation lasts about 35 days and starts with the first egg. The female incubates mainly, the male only occasionally replaces her. The chicks appear in the same sequence as the eggs were laid, so the second chick is 1 or 2 times younger than the first. This difference is quite enough for this younger and weaker chick to be constantly attacked by the older one and lack food. As a result of this competition for food, the youngest chick most often dies of hunger. It is noteworthy that the parents do not react in any way to this antagonistic relationship between the chicks.

During the first 5-6 weeks of the chicks' life, one of the parents is constantly in the nest (most often the female), and then the adults leave the nest and stay somewhere nearby. The chicks brought by them can already tear apart themselves. After 10-12 weeks, the chicks try to make their first flights, though not always successful. Even having already learned how to fly, young eagles remain for quite a long time (several weeks) in the area of \u200b\u200btheir parents.

Usually each pair grows no more than one chick.

Life span

In nature, bald eagles live up to 18-20 years, in captivity - more, up to about 36 years.

Life story at the Moscow Zoo

Now in our zoo, bald eagles are kept both at the exposition in the aviary "The Rock of Birds of Prey" in the Old Territory, and in the nursery, where the pair has been breeding regularly since 2010. The exposition has only one female so far.

The daily diet of bald eagles (like other 2 types of eagles) includes 700-800 g of meat, 200-800 g of fish (depending on the season) and 1 rat.

Hardware and software complexes "Orlan", "Orlan-M", "Orlan-R" (hereinafter referred to as complexes) are designed to measure the values \u200b\u200bof the current time, synchronized with the national time scale of the Russian Federation UTS (SU).

Description

The complexes are made in a metal case with organic glass inserts. Inside the case there are: a digital TV camera with IR illumination with a resolution of at least 2 Mpix, an electronic time synchronization unit, a GPS / GLONASS receiver, an Intel processor-based computer with an SSD data storage with installed Windows / Linux OS and utility software, as well as a heating control relay , cooling, battery charging, sensors (temperature, humidity, magnetic field), GSM module, air heater, fans, power supply (220 V AC, 12 V DC), auxiliary nodes and external interfaces.

The principle of operation of the complexes is as follows. The software provides the setting of camera parameters, such as exposure duration, operation on an external TRIG signal, gain level and others. Next, the time synchronizer board is interrogated whether the time value is valid or not, if not, the polling is repeated until the time values \u200b\u200bbecome valid. The software provides a frame capture request to the time synchronizer board. The time synchronizer generates a positive slope of the TRIG signal, and also fixes the value of the internal clock at this moment. This value, as well as the time validity flag, are sent to the calculator and processed by the software. The camera ensures that the frame is captured using the TRIG signal and also sends the frame to the calculator. The software provides reception of a frame timestamp from the synchronizer board and a frame from a TV camera. If the time stamp contains a valid time, the frame is recognized as containing a valid time with time stamping on the image with the synchronization error of the internal time scale over the GNSS channels ± 1 ms in relation to the time stamp in the frame, the frame is transmitted for further processing or sending to the user. The time synchronizer carries out continuous synchronization of the internal clock according to the GNSS signal (GPS and / or GLONASS), as well as self-test. If the GNSS signal is lost or the self-test fails, the time value is considered invalid.

When the Orlan complex enters the operating mode, the TV camera frames with the actual date and time of the exposure start (year, month, day, hour, minute, second, millisecond) are displayed on the screen of the complex and in the remote control software, as well as the word "OK" or "READY".

The complexes are made in three modifications - mobile "Orlan-M", special "Orlan-R" and stationary "Orlan". The main difference between the modifications is the appearance of the case and the scope of delivery, the metrological characteristics are the same.

Software

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Complexes "Orlan" contain embedded software (software), which ensures their operation, receiving and transmitting data, measuring and calculating time values. The identification data (features) of the software are given in Table 1.

The metrological characteristics of the Orlan complexes indicated in Table 2 are normalized taking into account software. The level of software protection against unintentional and deliberate changes is "high" according to R 50.2.077-2014.

Specifications

Table 2 - Basic metrological and technical characteristics

Limits of permissible absolute error of synchronization of the time scale of the output signal PPS (1 Hz) to the time scale UTC (SU), ms
PPS signal amplitude (1 Hz) at the output, not less, V
Main unit supply voltage, V
Power consumption no more, W
Power consumption without heating system, no more, W
Working conditions of use: Temperature, ° С Relative humidity at 25 ° С, up to,%	from minus 40 to plus 55 95
Overall dimensions "Orlan", "Orlan-M", (width x height x depth) with a protective visor, no more, mm:	250 x 250 x 400
Overall dimensions "Orlan-R", (width x height x depth) with a protective visor, no more, mm:	400 x 320 x 430
Weight "Orlan", "Orlan-M", no more, kg
Orlan-R weight, no more, kg
Average service life, years
MTBF, h

Type approval mark

is applied by installing a metallographic plate on the body of the complex and, using the typographic method, on the title pages of the ADEL.402100.001 Operation Manual and the Operation Manual for the AWP ADEL.402100.002 OM operator in the lower left corner.

Completeness

The completeness of the complex is shown in Table 3.

Name		Note
Hardware-software complex		"Orlan", "Orlan-M" or "Orlan-R"
Specialized software “Orlan. Operator workstation "
Mounting kit		"Orlan" or "Orlan-R"
		only "Orlan-M"
Battery charger designed for charging batteries from a 220 V alternating voltage network		only "Orlan-M"
Time indicator "Orlan-IV-1"
Adapter "Orlan DB15-BNC"
Manual		ADEL.402100.001 RE
Verification method		RT-MP-2848-441-2016
		ADEL. 402100.003 PS

Verification

carried out according to the document RT-MP-2848-441-2016 “GSI. Hardware-software complexes "Orlan", "Orlan-M", "Orlan-R" Method of verification ", approved by FBU" Rostest-Moscow "dated 18.02.2016

List of standards used in verification:

Time synchronization server SSV-1G, State Register 58301-14;

Frequency counter universal CNT-90XL, State Register 41567-09.

The verification mark is applied to the verification certificate.

Information on measurement methods

The measurement technique is given in the operation manual "Hardware and software complexes" Orlan "," Orlan-M "," Orlan-R "ADEL.402100.001 RE.

Regulatory and technical documents establishing requirements for hardware-software complexes "Orlan", "Orlan-M", "Orlan-R"

The bald eagle is a large predator of the hawk family, easily recognizable by the snow-white plumage of the head. This bird is the oldest representative of the avifauna of North America, as evidenced by fossil remains found in one of the Colorado caves. According to scientists, their age is about 670 thousand years.

Today, the bald eagle is a numerous, widespread species, but this was not always the case. The centuries-old history of birds is full of significant and tragic events.

Bald eagle hunting.

The Ups and Downs of the Bald Eagle

The indigenous population of the North American continent revered the bald eagle as a sacred bird, beautiful legends were made about it, images were applied to totem poles and gravestones. Bird feathers adorned the headdresses of the Indians of many tribes, symbolizing strength and honor, amulets from the claws protected and brought good luck.

According to experts, before the discovery of America by Europeans, the number of bald eagles was about half a million individuals. In the 18th century, birds gained incredible popularity among the new masters of the continent, their formidable and majestic appearance did not go unnoticed by the founding fathers, and in 1872 the bald eagle became the official symbol of the country. The proud profile of the predator appears on the Great Seal, coins, flags and other attributes of state power.

The first settlers began to exterminate bald eagles out of purely sporting interest, but until the 20th century, the bird population remained relatively safe. After World War II, predators were considered pests, kidnapping farm livestock and eating too many fish, and were rewarded for killing them. The population size was then estimated at 50 thousand individuals, and the active use of the insecticide DDT put the bald eagle on the brink of survival.

John F. Kennedy defended the birds and in 1963 the official population count gave a sad result: only 487 breeding pairs were found in the territory of 48 states. As protective measures, a ban was introduced on the use of DDT, shooting and unofficial ownership of birds, their status was assessed as endangered.

Only in 1995, the state of the bald eagle population was recognized as vulnerable, and in 2007 the species was considered not causing concern. Today, birds are still protected by the state, and their stylized images are used especially actively to emphasize the American origin of the brand.

Bald eagle: portrait.

What does a bald eagle look like

The bald eagle has a characteristic eagle appearance, and although it is considered one of the largest predators in North America, it is inferior in size to a closely related species - the white-tailed eagle and the largest representative of the hawk - the golden eagle.

The growth of an adult bird, taking into account the tail, is from 70 to 120 cm, the weight reaches 3-6.3 kg. Outwardly, individuals of both sexes look the same, but females are a quarter larger than males, so it is almost impossible to determine the sex of a bird in a photo of a bald eagle.

Predators have a massive hooked beak of golden yellow color, slightly flattened laterally, with a noticeably curved ridge and a straight mandible. The eyes are large, with a yellow iris, visual acuity is 8 times superior to that of a human. Strongly protruding brow ridges give the birds a characteristic frown.

The tail of the bald eagle is wedge-shaped, of medium length. Strong strong legs of predators are completely devoid of plumage and are colored in the color of the beak. Long, up to 15 cm fingers are armed with sharp strong claws. The front toes are designed to hold the prey, while the hind toe, with a particularly long claw, is used to pierce the prey. The fingers are equipped with special bony spines - spicules that help to hold the prey tightly.

The main color of the plumage of adult predators is dark brown, almost black, in sharp contrast to the white head and tail. This is how birds look in the sixth year of life, and at an earlier age, only an ornithologist can identify a bald eagle.

Bald eagle in flight.

Bald eagle in flight, front view.

A bald eagle takes off from a tree branch.

The bald eagle prepares to attack the fish.

Bald eagle: photo from the back.

Age metamorphosis

The bodies of newly hatched chicks are unevenly covered with grayish-white down, through which pink skin shines through. 3 weeks after birth, the skin of the chicks becomes bluish, and the legs turn noticeably yellow.

The first real plumage of juveniles is monochromatic, chocolate brown, only white spots stand out on the shoulders and the inner surface of the wing. The beak and iris of the eyes of birds of the first year of life are also dark brown.

Bald eagles 2-3 years old, thanks to the many white markings all over the body, become especially variegated and so far are completely unlike their parents. The brown color of the eyes gradually changes to gray, then turns yellow, the beak also becomes yellowish.

In the fourth year of life, an adult color begins to emerge in birds: the head and tail brighten noticeably, and the body darkens, a clear border forms between them. From 3.5 to 5 years old, only dark spots under the eyes testify to the young age of the predator, which disappear by 6 years.

Adolescent Bald Eagle: Color is not yet like that of an adult bird.

A teenage bald eagle with a caught fish.

Bald eagles: an adult bird (left) with a juvenile (right).

An adult bald eagle (left) sorts out a relationship with a teenager (right).

How to distinguish a bald eagle from similar species

The most similar color of plumage is that of the screamer eagle, an inhabitant of Africa, but its white color from the head extends down the neck and further to the upper chest and back.

A young bald eagle in its black and white variegated plumage can be mistaken for a golden eagle, but it has a shorter neck, and its legs are covered with feathers up to the tarsus. Young golden eagles have white markings only at the base of the wings and tail, and young eagles are completely covered with white spots. And if the wingspan of the adult representatives of the species is practically the same, then the bald eagle and the golden eagle soar in completely different ways.

Bald eagle wingspan

The photo of the bald eagle shows how wide and rounded the wings are. Their flight span ranges from 180 to 230 cm, which is 10 cm less than that of the golden eagle. It is very easy to distinguish a soaring eagle and a golden eagle: the eagle holds its spread wings parallel to the body, and the golden eagle lifts it above the body and pulls it forward in a V-shape.

The flapping flight of the bald eagle is measured with deep flaps of huge wings, its speed is about 70 km / h. In a dive flight, the birds accelerate to 120-160 km / h, significantly inferior to the golden eagle, which attacks the victim at a speed of up to 320 km / h.

The range of the bald eagle

The bird habitat covers the USA, Canada and some northern states of Mexico. Predator nests have also been seen on the Atlantic islands of Saint Pierre and Miquelon, which are owned by France.

Occasionally, the appearance of bald eagles is noted in the Far Eastern region of Russia. At first, birds were noticed on the Commander Islands, later on Bering Island, in the southeast of Kamchatka, in particular on the Kuril Lake.

Rare bird visits are recorded in Bermuda, the Caribbean, Belize, Puerto Rico and Ireland.

Bald eagles sort things out.

Bald eagle lifestyle

Inhabitants of the southern states, for example California and Florida, live sedentary, from colder regions birds migrate to the south for the winter, to the coast. During seasonal migrations, bald eagles gather in large groups, sometimes up to a thousand individuals, which is not typical for other feathered predators.

Favorite bird habitats are always located near the sea, bay, large lake or wide river. The richer the fish fauna of the reservoir, the higher the population density of bald eagles. Resting and nesting sites are usually located in the nearest forest, no further than 200 - 3000 m from the water.

Bald eagle just before the attack.

Three bald eagles on a dry felled trunk.

Bald eagles: male and female.

Bald eagle and snow.

A bald eagle attacks a heron, which spreads its wings and prepares for defense.

Features of the diet

All eagles are famous ichthyophages, the lion's share of their diet is fish. Depending on the habitat, these can be Pacific salmon species, herring, gerbil, representatives of the order of catfish, mullet, trout, pike, perch and other medium-sized fish species.

The second place in the diet of predators is taken by waterfowl and near-water birds: ducks, geese, mallards, grebes, gulls, cranes, pelicans, herons, terns, cormorants, guillemots and other feathered inhabitants of coastal waters.

An insignificant part of the main diet consists of small mammals: beavers, musk rats, striped raccoons, squirrels, gophers, hares and rabbits. Along with the golden eagle, the bald eagle can hunt small livestock, for example, young sheep, but these are isolated cases, because predators avoid human settlements. In the Pacific Islands, there are cases of attacks by bald eagles on baby seals and sea lions.

Predators do not disdain carrion: dead fish, corpses of large animals, food remnants after picnics, garbage in landfills.

Feeding methods

Highly artistic photographs of a bald eagle on the hunt showcase its eerie and brutal methods of foraging. The hunting skills of the predator are similar to those of the osprey, but unlike the latter, the eagle grabs fish at the very surface of the water, without wetting the feathers, and the osprey dives under the water after the prey. The eagle looks out for prey from a height, dives swiftly and grabs with a stranglehold. Sometimes predators roam in shallow water, pecking up fry.

The eagle can grab a flying bird from below, turning over and clutching its claws into the victim's stomach. The predator exhausts diving birds and animals with methodical attacks until they are no longer able to hide under water. Sometimes there are cases of collective hunting of a pair of predators, where one makes a distraction, and the other attacks from the rear.

In order not to share with relatives, the bald eagle eats the caught and killed prey in a secluded place, about 1 kg of food can be stored in the goiter, eating when hungry.

With the onset of cold weather, when it is already difficult to fish, predators become especially active scavengers, driving away the main competitors from the corpses of large animals - vultures, crows, foxes and even coyotes. Unlike the golden eagle, the bald eagle never engages in combat with a superior enemy.

The bald eagle stole the prey from the wolf.

The feeding area of \u200b\u200ba pair of predators ranges from 2.6 to 648 km 2 and during the mating season the birds become especially territorial.

The bald eagle hunts for fish.

A bald eagle glides over the water while hunting.

Bald eagle hunting.

Bald eagle breeding

These predators are monogamous and keep marital fidelity all their lives, even during wintering they keep close and can build a nest, although they do not breed.

Bald eagles reach reproductive age by 4-7 years. Mutual courtship is expressed in intricate flights, when birds arrange races with somersaults in the air, claw and spin beautifully, fall down, scattering directly above the ground. Then the male and the female sit on a tree and rub their beaks.

Bald eagle feeds chicks.

Bald eagle with chick.

The nest is built in the crown of a freestanding solid tree. Strong branches, corn stalks and dry grass are used for construction. The couple has been using the nest for many years, renovating and completing it. A nest of bald eagles, built near the city of St. Petersburg in Florida, got into the Guinness Book of Records. The diameter of the nest by 1963 was 2.9 m, the height reached 6 m, and the weight exceeded 2 tons.

The female lays from 1 to 3 white matte eggs weighing from 114 to 130 g. The female incubates, the male is engaged in foraging. After 35 days of incubation, the chicks hatch in turn. Fierce competition for food often ends in the death of the weaker.

At the age of 5-6 weeks, chicks already know how to tear apart the meat brought by their parents and jump on branches. The first flight of a bald eagle occurs at the age of 10-12 weeks and often ends in failure: the chick falls and is on the ground under the protection of its parents until it learns to fly. Chicks capable of flying do not stay near their parents for long, and then begin to lead an independent life. About half of bald eagles breed 2 times per season.

Top predators have practically no natural enemies, and many bald eagles live safely for about 15-20 years. In captivity, their life expectancy increases to 36-47 years.

The Indians honor the bald eagle as a divine bird, calling it a mediator between people and the Great Spirit who created the universe. In his honor, legends are made and rituals are dedicated, depicting on helmets, poles, shields, clothes and dishes. The symbol of the Iroquois tribe is an eagle perched on a pine tree.

Appearance, description of the eagle

The world learned about the bald eagle in 1766 from the scientific work of Karl Linnaeus. The naturalist gave the bird the Latin name Falco leucocephalus, attributing it to the falcon family.

The French biologist Jules Savigny did not agree with the Swede, in 1809, when he included the bald eagle in the genus Haliaeetus, which previously consisted only of the white-tailed eagle.

Two subspecies of the eagle are now known, differing exclusively in size. It is one of the most representative birds of prey in the vastness of North America: only the white-tailed eagle is larger than it.

Male bald eagles are noticeably smaller than their partners... Birds weigh from 3 to 6.5 kg, grow up to 0.7-1.2 m with a 2-meter (and sometimes more) span of wide rounded wings.

It is interesting!The eagle's legs are devoid of feathers and are colored (like the hooked beak) golden yellow.

It may seem that the bird is frowning: this effect is created by growths on the brows. The frightening look of the eagle is contrasted with its weak voice, which is manifested by a whistle or high-pitched cry.

Strong fingers grow up to 15 cm, ending in sharp claws. The rear claw acts like an awl, piercing the victim's vital organs, while the front claws prevent it from escaping.

The eagle's feather vestment takes on a complete look after 5 years. At this age, the bird can already be distinguished by its white head and tail (wedge-like) against the general dark brown plumage background.

Wildlife

A bald eagle cannot live far from water. A natural body of water (lake, river, estuary or sea) should be located 200-2000 meters away from the nesting site.

Habitat, geography

The eagle chooses coniferous forests or deciduous groves for nesting / resting, and deciding on the reservoir, proceeds from the "assortment" and the amount of game.

The range of the species extends to the USA and Canada, fragmentarily covering Mexico (northern states).

It is interesting! In June 1782, the bald eagle became the official emblem of the United States of America. Benjamin Franklin, who insisted on the choice of the bird, later regretted this, pointing out its "bad moral qualities." He meant the eagle's love for carrion and the tendency to wean prey from other predators.

Orlan is seen on the islands of Miquelon and Saint-Pierre, which belong to the French Republic. The nesting areas are "scattered" extremely unevenly: their concentrations are found on the sea coasts, as well as on the coastal zones of lakes and rivers.

Occasionally, bald eagles penetrate the US Virgin Islands, Bermuda, Ireland, Belize and Puerto Rico. Eagles have been repeatedly noticed in our Far East.

Bald eagle lifestyle

The bald eagle is one of the rare feathered predators capable of creating massive concentrations. Hundreds and even thousands of eagles gather where there is a lot of food: close to hydroelectric power plants or in areas of mass cattle mortality.

When the reservoir freezes, birds leave it, rushing to the south, including to warm sea shores. Adult eagles can stay in their native land if the coastal area is not covered with ice, which allows them to fish.

It is interesting!In its natural environment, the bald eagle lives from 15 to 20 years. It is known that one eagle (ringed in childhood) lived to almost 33 years. In favorable artificial conditions, for example, in open-air cages, these birds live for over 40 years.

Diet, nutrition

The menu of the bald eagle is dominated by fish and much less often by medium-sized game. He does not hesitate to select the prey of other predators and does not shun carrion.

As a result of research, it turned out that the diet of an eagle looks like this:

Fish - 56%.
Bird - 28%.
Mammals - 14%.
Other animals - 2%.

The last position is represented by reptiles, primarily turtles.

On the islands of the Pacific Ocean, sea eagles chase sea otters, as well as seal and sea lion cubs. The birds prey on muskrats, rabbits, ground squirrels, raccoons, hares, squirrels, rats and young beavers. It costs nothing for an eagle to pick up a small sheep or other pet.

The feathered eagle prefers to take it by surprise on land or water, but can catch it on the fly. So, the predator flies up to the goose from below and, turning over, clings to the chest with its claws. In pursuit of a hare or a heron, the eagles form a temporary alliance, in which one of them distracts the object, and the other attacks from the rear.

The bird hunts down fish, its main prey, in shallow water: like an osprey, the eagle looks after the prey from a height and dives at it at a speed of 120–160 km / h, seizing it with tenacious claws. At the same time, the hunter tries not to wet his feathers, but this does not always work. The eagle eats both freshly caught and sacked fish.

By winter, when the reservoirs freeze, the share of falling in the bird menu increases significantly. Eagles circle around the carcasses of large and medium-sized mammals, such as:

reindeer;
moose;
bison;
wolves;
rams;
cows;
arctic foxes and others.

Smaller scavengers (foxes and coyotes) cannot compete with adult eagles in the fight for corpses, but they are able to drive away the unmatched ones.

Young eagles find another way out - not being able to hunt live game, they not only take prey from small birds of prey (hawks, crows and gulls), but also kill the robbed.

The bald eagle does not hesitate to pick up food waste in landfills or leftover food near campgrounds.

The main enemies of the bird

If you do not take into account humans, the list of natural enemies of the eagle should include the Virginia eagle owl and the striped raccoon: these animals do not harm adults, but threaten the offspring of eagles, destroying eggs and chicks.

The danger also comes from Arctic foxes, but only if the nest is arranged on the surface of the earth.... Ravens can disturb the eagles at the time of incubation of their chicks, without going so far as to ruin the nests themselves.

It is interesting! The Indians made whistles for warriors and tools to drive out ailments from the bones of an eagle, and jewelry and amulets from bird's claws. An Ojibwe Indian could receive a feather for special merit such as scalping or capturing an enemy. Feathers, personifying glory and power, were kept in the tribe, passing by inheritance.

Bald eagle breeding

Birds enter fertile age no earlier than four, sometimes six to seven years. Like many hawks, bald eagles are monogamous. Their union breaks up only in two cases: if there are no children in the pair or one of the birds does not return from the south.

A marriage is deemed to be sealed when the eagles begin to build a nest - a large-scale structure of twigs and twigs placed on top of a tall tree.

This structure (weighing a ton) is larger than the nest of all North American birds, reaching 4 m in height and 2.5 m in diameter. The construction of the nest, which is carried out by both parents, lasts from a week to 3 months, but the branches are usually laid by the partner.

At the right time (with an interval of one or two days), she lays 1-3 eggs, less often four. If the clutch is destroyed, eggs are re-laid. Incubation, assigned mainly to the female, takes 35 days. It is only occasionally replaced by a partner whose task is to find food.

The chicks have to fight for food: it is not surprising that the younger ones die. When the chicks are 5-6 weeks old, the parents fly away from the nest, following the children from the nearest branch. At this age, babies already know how to jump from branch to branch and tear meat into pieces, and after 10-12.5 weeks they start flying.

Number, population

Before the exploration of North America by Europeans, 250-500 thousand bald eagles lived here (according to ornithologists). The settlers not only changed the landscape, but also shamelessly shot birds, enticed by their beautiful plumage.

The emergence of new settlements led to a decrease in the supply of water, where the eagles fished. Farmers killed eagles on purpose, taking revenge on them for stealing domestic sheep / chickens, and for fish that the villagers did not want to share with the birds.

Thallium sulfate and strychnine were also used: they were sprinkled on the carcasses of cattle, protecting them from wolves, eagles and coyotes. The population of eagles has declined so much that the bird has almost disappeared in the United States, remaining only in Alaska.

It is interesting!In 1940, Franklin Roosevelt was forced to issue the Bald Eagle Conservation Act. When the Second World War ended, the number of the species was estimated at 50 thousand individuals.

A new attack awaited the Eagles, the poisonous chemical DDT, which was used in the battle with harmful insects. The drug did not harm adult eagles, but did affect the eggshells, which cracked during incubation.

Thanks to DDT, there were only 487 bird pairs in the United States by 1963. After the ban of the insecticide, the population began to recover. Now the bald eagle (according to the International Red Data Book) is classified as a species of minimal concern.

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