Hardware-software complexes "Orlan", "Orlan-M", "Orlan-R" (hereinafter referred to as the complexes) are designed to measure the values of the current time, synchronized with the national time scale Russian Federation UTS (SU).
Description
The complexes are made in a metal case with organic glass inserts. Inside the case are located: a digital television camera with IR illumination with a resolution of at least 2 megapixels, an electronic time synchronization unit, a GPS/GLONASS receiver, a calculator based on an Intel processor with an SSD data drive with installed Windows/Linux OS and service 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 for setting camera parameters, such as exposure duration, operation with an external TRIG signal, gain level, and others. Next, the time synchronizer board is polled whether the time value is valid or not, if it is not, the poll is repeated until the time values become valid. The software provides a frame capture request to the time synchronizer board. The time synchronizer generates a positive edge 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, is sent to the calculator and processed by the software. The camera performs frame capture on the TRIG signal and also sends the frame to the calculator. The software ensures the reception of the frame time stamp from the synchronizer board and the frame from the camera. If the time stamp contains a valid time, the frame is recognized as containing a valid time with time imprinted on the image with an internal time scale synchronization error over GNSS channels of ±1 ms with respect to the time stamp in the frame, the frame is transmitted for further processing or sending to the user. The time synchronizer performs continuous synchronization of the internal clock using a GNSS signal (GPS and/or GLONASS), as well as a 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, on the screen of the complex and in the remote control software, frames of the camera with the actual date and time of the start of the exposure (year, month, day, hour, minute, second, millisecond) are displayed, 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
Place for factory stickers
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Orlan complexes contain built-in software (software) that ensures their operation, data reception and transmission, measurement and calculation of time values. Identification data (signs) of software are given in Table 1.
The metrological characteristics of the Orlan complexes, indicated in Table 2, are normalized taking into account software. Protection level software from unintentional and intentional changes "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 than, V | |
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Supply voltage of the main unit, V | |
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Power consumption, no more than, W | |
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Power consumption without heating system, no more than, W | |
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Working conditions of application: Temperature, °C Relative humidity at 25 °С, up to, % |
from minus 40 to plus 55 95 |
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Overall dimensions "Orlan", "Orlan-M", (width x height x depth) with a protective visor, not more than, mm: |
250 x 250 x 400 |
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Overall dimensions of "Orlan-R", (width x height x depth) with a protective visor, not more than, mm: |
400 x 320 x 430 |
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Weight "Orlan", "Orlan-M", not more than, kg | |
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Mass "Orlan-R", no more than, kg | |
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Average service life, years | |
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Time to failure, h |
Type approval mark
is applied by installing a metallographic plate on the body of the complex and by typographic method on title pages Operation manual ADEL.402100.001 RE and Operator's manual AWP ADEL.402100.002 RE 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" | ||
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Mounting kit |
"Orlan" or "Orlan-R" |
|
|
only "Orlan-M" |
||
|
Charger designed to charge batteries from the mains AC voltage 220 V |
only "Orlan-M" |
|
|
Time indicator "Orlan-IV-1" | ||
|
Adapter "Orlan DB15-BNC" | ||
|
Manual |
ADEL.402100.001 RE |
|
|
Verification procedure |
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 February 18, 2016.
List of standards used for verification:
Time synchronization server SSV-1G, State Register 58301-14;
Universal frequency meter CNT-90XL, State Register 41567-09.
The verification mark is applied to the verification certificate.
Information about measurement methods
The measurement technique is given in the operating manual "Hardware-software complexes "Orlan", "Orlan-M", "Orlan-R" ADEL.402100.001 RE.
Regulatory and technical documents that establish requirements for hardware and software complexes "Orlan", "Orlan-M", "Orlan-R"
Speaking of birds of prey, one cannot help but admire their strength, speed, agility and sharp eyesight. They soar in the sky over forests, fields, rivers, lakes and seas, striking with their size and power. In addition to appearance, these birds have many advantages, and today we’ll talk in more detail about one of the hawk representatives - orlane.
The appearance of an eagle
Orlan belongs to the buzzard subfamily, translated from Greek, its name means marine. Like all members of the species, eagle a 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) fingers have small outgrowths to make it easier to hold prey, especially slippery fish.
The tarsus is naked, without feathers. The massive beak is hooked, yellow. Brow ridges protrude above the keen yellow eyes, 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 at different types differently. May be white head, shoulders, body 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 distributed quite widely, almost everywhere except Antarctica and South America. 4 species of eagles are found in Russia. The most common is the white-tailed eagle, which lives almost everywhere where there are fresh or salt water bodies. The long-tailed eagle belongs to the steppe species, living mainly from the Caspian Sea to Transbaikalia. Steller's sea eagle found mainly on the Pacific coast.
Pictured is a Steller's Eagle
bald eagle lives in North America, sometimes flying to the Pacific coast, it is considered symbol United States and is depicted on the coat of arms and other state signs.
Pictured is a bald eagle
The screaming eagle lives in southern Africa and is the national of some countries there. The largest habitats are in the lower reaches of the Volga and in the Far East, as these places are rich in fish - the main food of these predators.
All sea eagles settle near large reservoirs, on the shores of the seas, estuaries, rivers, lakes. They try not to fly into the very depths of the land. They rarely migrate, but if the waters in which they get food freeze, then the birds fly closer to the south for the winter.
Each stacked couple 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 hatch chicks. The rest hours of the sea eagles are usually spent in the mixed forest.
Pictured is a screamer eagle
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 hold smaller fish with its long claws. It feeds on a predator and a bird that lives near water bodies -,.
Small mammals are also on the menu, these are,. Various, crustaceans, and others, the eagle can also catch, but they interest him in much smaller quantities.
Carrion is also suitable for food, birds will not disdain washed ashore, fish, corpses of various animals. In addition, as a large predator, the eagle considers it not shameful to take prey from smaller and weaker hunters, or even steal it from their own gaping brethren.
The eagle prefers to hunt in shallow water, in those places where the fish are the most and it is not difficult to get it. Having noticed the victim, the bird falls down like a stone, grabs the prey and rises with it into the air.
Feathers during such a hunt do not get wet. Sometimes a predator just walks on the water, pecking out small fish from there. But more often the prey is quite large, the eagle is able to hold weight up to 3 kg. If the weight turned out to be unbearable, the predator can swim with it to the shore, where it will happily dine.
Sometimes a pair of eagles hunt together, especially for larger and 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 makes waterfowl dive by circling above them and frightening them. When the duck is tired and weak, it will be easy to catch and pull it ashore. During the meal, the eagle presses food to the branches of trees 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 gather may well force him to share. Large prey is enough for the sea eagle for a long time, about one kilogram of food can remain in the crop, providing the bird for several days.
Reproduction and life span of the eagle
Like other birds of this species, sea eagles are monogamous. But, if one dies, the second finds a replacement for her. The same happens if the "family" was unable to produce offspring. The pair is formed at a young age, this can happen both in spring and during wintering. In March-April, the breeding season begins. Enamored eagles circle in the sky, grapple with their claws and dive sharply.
Pictured is a white-tailed eagle's nest
Having tuned in the right way, future parents begin to build a nest, or, if the couple is old, restore last year's one. The male provides the female with building materials, which she lays. Eagles nest very large, usually about a meter in diameter and up to a ton in weight.
Such a heavy bird structure is placed on an old, dry tree, or on a separate rock. The main thing is that the support should withstand, and various terrestrial predators could not get to the eggs and chicks.
After 1-3 days, the female lays 1-3 white, matte eggs. The clutch is incubated by the expectant mother 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, 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 stay close to their parents. Only by 4 years of life the eagles become sexually mature. But this is normal, considering that these birds live for about 20 years.
The Indians honor the bald eagle as a divine bird, calling it an intermediary between people and the Great Spirit who created the Universe. In his honor, legends are composed and rituals dedicated, depicted on helmets, pillars, shields, clothes and utensils. 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 Carl Linnaeus. The naturalist gave the bird the Latin name Falco leucocephalus, attributing it to the falcon family.
The French biologist Jules Savigny disagreed with the Swede, in 1809 including the bald eagle in the genus Haliaeetus, which previously consisted only of the white-tailed eagle.
Now two subspecies of the eagle are known, distinguished only by size. It is one of the most representative birds of prey in the world. North America: only the white-tailed eagle is larger than it.
Male bald eagles are noticeably smaller in size than their female 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 legs of the eagle are devoid of feathers and are colored (like the hook-shaped beak) in a golden yellow color.
It may seem that the bird is frowning: this effect is created by growths on the eyebrows. The intimidating appearance of the eagle is contrasted by its weak voice, manifested by a whistle or a high-pitched scream.
Strong fingers grow up to 15 cm, ending in sharp claws. The back claw acts like an awl, piercing the victim's vitals, while the front claws keep it from escaping.
The eagle's feather dress 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 background of plumage.
Living in the wild
The bald eagle cannot live far from water. A natural body of water (lake, river, estuary or sea) should be 200-2000 meters away from the nesting site.
Habitats, geography
The eagle chooses coniferous forests or hardwood groves for nesting/resting, and when deciding on a reservoir, it proceeds from the "range" 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 choosing the bird, later regretted it, pointing out its "bad moral character". He meant the eagle's love of carrion and the tendency to take prey from other predators.
Orlan is seen on the islands of Miquelon and Saint-Pierre, belonging to the French Republic. Nests are "scattered" extremely unevenly: their accumulations fall on the sea coasts, as well as coastal zones of lakes and rivers.
Occasionally, bald eagles enter the US Virgin Islands, Bermuda, Ireland, Belize and Puerto Rico. Orlans have been repeatedly noticed in our Far East.
Bald Eagle Lifestyle
The bald eagle is one of the rare raptors capable of creating mass concentrations. Hundreds and even thousands of sea eagles gather where there is a lot of food: close to hydroelectric power plants or in areas of mass loss of livestock.
When the reservoir freezes, the birds leave it, rushing to the south, including to warm sea shores. Adult sea eagles can stay in their home areas if the coastal zone is not covered with ice, which allows them to fish.
It is interesting! In the natural environment, the bald eagle lives from 15 to 20 years. It is known that one (ringed in childhood) sea eagle lived to almost 33 years. In favorable artificial conditions, for example, in aviaries, these birds live for more than 40 years.
Diet, food
The menu of the bald eagle is dominated by fish and much less often by small 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 eagle's diet looks something 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, eagles chase sea otters, as well as seal cubs and sea lions. Birds prey on muskrats, rabbits, ground squirrels, striped raccoons, hares, squirrels, rats and young beavers. It doesn't cost anything for an eagle to kill a small sheep or other domestic animal.
The feathered eagle prefers to be taken by surprise on land or in the water, but it can also be caught on the fly. So, a predator flies up to a 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 second attacks from the rear.
The bird tracks down fish, its main prey, in shallow water: like an osprey, the eagle watches the prey from a height and dives at it at a speed of 120-160 km / h, capturing it with tenacious claws. At the same time, the hunter tries not to wet his feathers, but this does not always work out. The eagle eats both freshly caught and dead fish.
By winter, when the reservoirs freeze, the share of carrion in the bird's menu increases significantly. Eagles circle around the carcasses of large and medium-sized mammals, such as:
- reindeer;
- moose;
- bison;
- wolves;
- sheep;
- cows;
- foxes and others.
Smaller scavengers (foxes and coyotes) cannot compete with adult eagles in the fight for corpses, but are able to drive away the unmature ones.
Young eagles find another way out - not knowing how to hunt live game, they not only take prey from small birds of prey (hawks, crows and gulls), but also kill the robbed ones.
The bald eagle does not disdain to pick up food waste in landfills or food leftovers near campsites.
The main enemies of the bird
If we do not take into account humans, the list of natural enemies of the sea eagle should include the Virginian eagle owl and the raccoon 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 built on the surface of the earth.. Ravens can disturb the eagles at the time of incubation of chicks, without, however, reaching the ruin of the nests themselves.
It is interesting! The Indians made whistles for warriors and tools for expelling illnesses from the bones of an eagle, and jewelry and amulets from bird claws. An Ojibwe Indian could receive a feather for special merit, such as scalping or capturing an enemy. Feathers, personifying glory and strength, were kept in the tribe, passing by inheritance.
Bald eagle breeding
Birds enter the fertile age no earlier than four, sometimes six or seven years. Like many hawks, bald eagles are monogamous. Their union breaks up only in two cases: if the couple has no children or one of the birds does not return from the south.
The marriage union is considered sealed when the eagles begin to build a nest - a large-scale structure of twigs and branches, erected on top of a tall tree.
This structure (weighing a ton) is larger than the nests of all North American birds, reaching 4 m in height and 2.5 m in diameter. The construction of the nest, which is done by both parents, lasts from a week to 3 months, but the partner usually lays the branches.
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, the eggs are laid again. Incubation, entrusted mainly to the female, takes 35 days. It is only occasionally replaced by a partner whose task is to search for food.
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, watching 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 Europeans explored North America, there lived (according to ornithologists) 250-500 thousand bald eagles. The settlers not only changed the landscape, but also shamelessly shot the birds, seduced by their beautiful plumage.
The emergence of new settlements led to a decrease in water supplies, where the eagles fished. Farmers killed eagles purposefully, avenging 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 sprinkled carcasses of cattle, protecting them from wolves, eagles and coyotes. The population of sea eagles has declined so much that in the United States the bird has almost disappeared, remaining only in Alaska.
It is interesting! In 1940, Franklin Roosevelt was forced to issue the Bald Eagle Protection Act. When World War II ended, the population of the species was estimated at 50,000 individuals.
Orlanov was waiting for a new misfortune, the pesticide DDT, used in the battle with harmful insects. The drug did not harm adult eagles, but affected the egg shells, which cracked during incubation.
Thanks to DDT, by 1963 there were only 487 bird pairs in the United States. After the insecticide was banned, the population began to recover. Now the bald eagle (according to the international Red Book) is classified as a species of minimal concern.
The bald eagle is a large predator of the hawk family, easily recognizable by the snow-white head plumage. This bird is the oldest representative of the avifauna of North America, as evidenced by the fossil remains found in one of the caves in Colorado. According to scientists, their age is about 670 thousand years.
Today, the bald eagle is a numerous, widespread species, but this has not always been the case. The centuries-old history of birds is full of significant and tragic events.
Bald eagle on the hunt. 
Bald eagle on the hunt. 
"Ups and Downs" door Bald Eagle
The indigenous population of the North American continent revered the bald eagle as a sacred bird, beautiful legends were composed 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, claw amulets 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 owners 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.
Even 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 the Second World War, predators were considered pests, stealing farm livestock and eating too many fish, and a cash reward was supposed to kill them. The population 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 came out in defense of birds and in 1963 the official count of the population gave a sad result: only 487 breeding pairs were found in 48 states. As protective measures, a ban on the use of DDT, shooting and unofficial possession of birds was introduced, their status was assessed as endangered.
It was only in 1995 that the state of the bald eagle population was recognized as vulnerable, and in 2007 the species was considered not to cause concern. Today, the 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. 
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 hawks - the golden eagle.
The height 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, golden-yellow beak, slightly flattened laterally, with a noticeably curved ridge and a straight mandible. The eyes are large, with a yellow iris, visual acuity exceeds the human by 8 times. A characteristic gloomy expression is given to the birds by strongly protruding brow ridges.
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 fingers are designed to hold prey, while the rear finger, with a particularly long claw, serves to pierce the prey. The fingers are equipped with special bone spikes - spicules, which help to hold prey tightly.
The main color of the plumage of adult predators is dark brown, almost black, in sharp contrast with the white head and tail. This is how birds look at 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 is preparing to attack the fish. 
Bald Eagle: photo from the back. 
Age metamorphoses
The bodies of newly hatched chicks are unevenly covered with grayish-white fluff, 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 young is monophonic, chocolate brown, only white spots stand out on the shoulders and the inner surface of the wing. The beak and iris of the eyes in birds of the first year of life are also dark brown.
Bald eagles 2-3 years old, due to the many white marks all over the body, become especially colorful and so far completely unlike their parents. The brown color of the eyes is gradually replaced by gray, then turns yellow, the beak also becomes yellowish.
In the fourth year of life, the 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, only dark spots under the eyes testify to the young age of the predator, which disappear by the age of 6.
Juvenile bald eagle: the color is not yet like that of an adult bird. 
A juvenile bald eagle with a caught fish. 
Bald eagles: adult (left) with juvenile (right). 
An adult bald eagle (left) sorts things out with a juvenile (right). 
How to distinguish a bald eagle from similar species
The most similar plumage color is 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 motley plumage can be mistaken for a golden eagle, but it has a shorter neck, and legs are covered with feathers to the very tarsus. Young golden eagles have white markings only at the base of the wings and tail, while young eagles are completely strewn with white spots. And if the wingspan of adult representatives of the species is almost the same, then the bald eagle and golden eagle soar in completely different ways.
bald eagle wingspan
The photo of the bald eagle shows how wide and rounded the wings of the bird are. Their span in flight ranges from 180 to 230 cm, which is 10 cm less than that of the golden eagle. Soaring eagles and golden eagles are very easy to distinguish: the eagle holds open 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 flapping of huge wings, its speed is about 70 km/h. In a dive flight, the birds accelerate up to 120-160 km/h, significantly yielding to the golden eagle, which attacks the prey at a speed of up to 320 km/h.
Bald eagle range
The bird's habitat covers the United States, Canada and some northern states of Mexico. Raptor nests are also 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 flights are observed in Bermuda, Caribbean islands, Belize, Puerto Rico and Ireland.
Bald eagles sort things out. 
Bald Eagle Lifestyle
The inhabitants of the southern states, such as California and Florida, live sedentary, from colder regions, birds migrate south to the coast for the winter. During seasonal migrations, bald eagles gather in large groups, sometimes up to a thousand individuals, which is not typical for other raptors.
Favorite biotopes of birds are always located near the sea, bay, large lake or wide river. The richer the ichthyofauna of the reservoir, the higher the population density of bald eagles. Places of rest and nesting are usually located in the nearest forest, no further than 200 - 3000 m from the water.
A bald eagle moments before the attack. 
Three bald eagles on a dry fallen trunk. 
Bald eagles: male and female. 
Bald eagle and snow. 
The bald eagle attacks the heron, which has spread its wings and is preparing for defense. 
Features of the diet
All sea eagles are known ichthyophages, the lion's share of their diet is fish. Depending on the habitat, these can be Pacific salmon species, herring, gerbil, catfish, mullet, trout, pike, perch and other medium-sized fish species.
The second place in the diet of predators is occupied 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 is made up of medium-sized mammals: beavers, musky rats, striped raccoons, squirrels, ground squirrels, hares and rabbits. Along with the golden eagle, the bald eagle can prey on small livestock, such as young sheep, but these are isolated cases, because predators avoid human settlements. In the Pacific Islands, bald eagles have been known to attack baby seals and sea lions.
Predators do not disdain carrion: dead fish, corpses of large animals, food leftovers after picnics, garbage in landfills.
Foraging methods
Highly artistic photographs of the bald eagle on the hunt demonstrate its creepy and brutal methods of obtaining food. The hunting skills of a 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 for the victim. The eagle looks out for prey from a height, dives rapidly and clings with a stranglehold. Sometimes predators roam in shallow water, pecking at fry.
An eagle can grab a flying bird from below, turning over and grabbing its claws into the stomach of the victim. 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 distracting maneuver, 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, when it is hungry.
With the onset of cold weather, when it is already difficult to fish, predators become especially active scavengers, driving away the main competitors - vultures, crows, foxes and even coyotes - from the corpses of large animals. Unlike the golden eagle, the bald eagle never fights a superior enemy.
The bald eagle stole prey from the wolf. 
The feeding territory of a 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 on the hunt. 
Bald eagle breeding
These predators are monogamous and remain faithful all their lives, even during the winter they stay 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 the birds arrange races with somersaults in the air, clutch with their claws and spin beautifully, fall down, flying right above the ground. Then the male and female sit on a tree and rub their beaks.
The bald eagle feeds the chicks. 
Bald eagle with chick. 
The nest is built in the crown of a detached massive tree. Strong branches, corn stalks and dry grass are used for construction. The couple has been using the nest for many years, renovating and building on 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 obtaining food. After 35 days of incubation, the chicks hatch in turn. Fierce competition for food often ends in the death of the weaker one.
At the age of 5-6 weeks, the chicks already know how to tear the meat brought by their parents and jump on the 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 twice a 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.
Russian name- Bald Eagle
Latin name- Haliaeetus leucocephalus
Detachment- falconiformes
Family- hawks
The bald eagle was recognized as the national bird of the United States in 1782, and since then its image has been featured 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 the two existing subspecies, H.l. leucocephalus (it is called nominal), is included in the IUCN Red List.
View and person
Despite their "state" status and legislative protection, the number of bald eagles in the 19th and 20th centuries. decreased sharply. The main reasons for this were mass extermination and economic activity person. The most dangerous for the sea eagle (as, indeed, for all other species of birds of prey) was the widespread use of DDT and other insecticides that 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 US currently has laws against killing or capturing live bald eagles without a permit.
In most 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.
Spreading
The bald eagle lives in Canada, the United States and in some areas in northern Mexico. Its distribution is characterized by extreme unevenness, with the largest number of nesting pairs concentrated on sea coasts and near large rivers and lakes.
Until the end of the twentieth century. the bald eagle has occasionally been observed in the Russian Far East, but these were always only occasional sightings with no signs of nesting.
Sea eagle populations living on the sea or ocean coast lead a sedentary lifestyle, 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, wingspan 180-230 cm, weight - 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 further south.
The beak is large, hook-shaped, golden yellow in adult birds. The legs are also yellow, and the tarsus and fingers are devoid of plumage. The fingers are long, about 15 cm, with sharp claws. With the front fingers the eagle holds the victim, and with the claw of the back finger it kills it.
The coloration of adult birds looks contrasting and very impressive - a dark brown body and a pure white head. But the eagles acquire such an outfit only at the age of 5., Approaching the 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 importance are aquatic and semi-aquatic birds. With a shortage or unavailability of fish, birds can form the basis of nutrition, and their content in the diet of sea eagles increases from 7-10% to 80%. The predation of sea eagles is most dangerous for bird colonies, where adult birds, chicks, and eggs become easy prey. Of the mammals, bald eagles can prey on medium-sized terrestrial animals, and in some places on 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 daytime. (It is not without reason that another name for falconiformes is diurnal birds of prey).
Vocalization
The voice of the bald eagle is surprisingly weak and quiet - it is either a high-pitched scream or a whistle. In young birds, the voice is sharper and rougher. Adult eagles can most often be heard during the “changing of the guard” on the nest during incubation, as well as in places of mass accumulation 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 eagles. Their pairs are constant, but outside the nesting period, the birds lead a solitary lifestyle. The pair joins only during the nesting period.
During winter migrations, a certain number of eagles may gather together in one place, but no strict hierarchy is observed between them.
Reproduction and parenting behavior
The breeding season of bald eagles begins with amazingly beautiful display flights of both birds, during which they chase each other, make deep dives in the air and turn upside down.
The pair then settle in their nesting area. The territory they protect around the nest is approximately 1-2 sq. km, but may be more or less depending on the number of neighboring pairs and the availability of available prey.
Nest building begins in various US states in different time, starting from the end of September until 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 free flight of such large birds and no further than 1-2 km from the water. Among American ornithologists, there is an opinion that the bald eagle's nest is the largest among all birds in North America: it can reach a diameter of 2.5 m and 4 m in height, and weigh about 1 ton. The eagles fasten the main branch frame with grass, dry corn stalks or dry algae. Building a nest or renovating it takes from several days to 3 months. Both parents participate in this work, but still more often the male only brings construction material and the female lays it in the nest. In addition to the main nest on the site of each pair, there may be several spare ones.
Laying takes place 1-3 months after the start of nest construction. The clutch usually contains 2 large light eggs (from 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 mainly incubates, 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 seconds 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 such competition for food, the youngest chick most often dies of starvation. It is noteworthy that the parents do not react in any way to these antagonistic relationships between the chicks.
During the first 5-6 weeks of the life of the chicks, 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 can already tear the food they bring by themselves. After 10-12 weeks, the chicks try to make their first flights, although not always successful. Even having already learned to fly, young eagles still stay for quite a long time (several weeks) on the site of their parents.
Usually, each pair grows no more than one chick.
Lifespan
In nature, bald eagles live up to 18-20 years, in captivity - more, up to about 36 years.
History of life in the Moscow Zoo
Bald eagles are now kept in our zoo both on display in the Birds of Prey Rock aviary in the Old Territory, and in the nursery, where the pair has been breeding regularly since 2010. So far, only one female has been kept on display.
The daily diet of bald eagles (as well as other 2 species of eagles) includes 700-800 g of meat, 200-800 g of fish (depending on the season) and 1 rat.
