The osprey is a large diurnal bird of prey. One of the 6 species of birds with a cosmopolitan distribution. A characteristic feature is that it feeds almost exclusively on fish. Represents the monotypic family Skopins (Pandionidae). Refers to a protected species.
Species origin and description
The species was described by Linnaeus in 1758. The generic name Pandion is given in honor of the mythological Athenian king Pandion I, who was turned into this bird by the divine will of Zeus. Although there is a version that Pandion II was meant and his son turned into a bird. The specific epithet “haliaetus” is composed of the Greek words meaning “sea” and “eagle”. The origin of the Russian name is unknown.
The most ancient fossil remains of representatives of this family. Skopins were found in Egypt and Germany and date back to the early Oligocene (about 30 million years ago). Fossils that can definitely be attributed to the osprey genus were found in later, Miocene — Pleistocene deposits in southern North America. The closest relatives of the osprey unite in the detachment of the Yastrebins.
Populations of the modern osprey in different geographical regions have pronounced features, which makes it possible to distinguish 4 subspecies:
- type subspecies living in Eurasia, the largest, with a dark color. Migratory;
- Caroline subspecies common in North America. In general, it looks like a typical one. Migratory;
- Ridgway subspecies found in the Caribbean. Distinguished by a bright head (in the sense of color, not mind). Lives settled;
- the crested subspecies inhabits Australia and Oceania, the Indonesian archipelago. Individuals are small, with characteristically raised feathers on the back of the head – combs.
The last subspecies is often distinguished by morphologists as an independent species: the crested or eastern osprey (Pandion cristatus). Although researchers who prefer molecular genetic methods of classification believe that all subspecies equally deserve species status.
Appearance and features
Sexual dimorphism is not very distinct. Females are somewhat larger and heavier than males, their weight can reach 2 kg, while males weigh 1.2 – 1.6 kg. An adult bird reaches 55 – 58 cm in length. The wingspan is absolutely incredible — in human height (up to 170 cm)! Flight feathers of the first order in gliding flight look like spread fingers.
A head with a typical predatory beak – a hook and a short crest on the back of the head, which the osprey can raise. The paws of the osprey are fishing tackle. They are surprisingly long and armed with sickle-shaped claws, the fingers are covered with spikes on the inside, and the outer one is clearly protruding back. The valves protect the nasal passages from water.
The coloring is contrasting, sustained in white and brownish colors. The crown, the entire underside of the body, the feather “trousers” of powerful paws and covert feathers on the underside of the wings are painted white. The back of the neck, back and top of the wings are brown. A brown stripe, like a bandage, crosses the eye of a predator from the beak to the neck. Spots of the same color are present at the carpal folds, on the chest they form a motley “necklace”, and on the tail and underside of the second and third order flight feathers – stripes. The skin of the legs is gray, the beak is black and the yellow burning eye.
Females wear bright well-defined “necklaces” and are generally darker. Young ospreys up to 18 months old are distinguished by faded “necklaces”, a scaly pattern on the back and along the top of the wings, and orange-red eyes. Downy chicks after birth are whitish with dark brownish spots, later brown striped-speckled.
Where does the osprey live?
The range of the osprey with all subspecies covers the temperate, subtropical and tropical climates of Eurasia, Africa, the Americas, as well as Australia and Oceania. Birds are distributed unevenly over the territory of the range, they are quite rare and scattered. Desert and high-mountain areas are avoided.
It is possible to distinguish areas of the range where:
- migratory birds nest;
- settled ospreys live;
- migratory birds are encountered during seasonal migrations;
- migrants from the north winter.
On the Russian territory, the northern border of the range approximately coincides with 67 ° N. in the European part, then passes along a latitude of 66 ° in the Ob basin, to the east it shifts even further south: to the mouth of the river. Lower Tunguska, lower reaches of the Vilyui, lower reaches of the Aldan. Along the coast of Okhotsk it runs north of Magadan to Kamchatka. The southern border in the European part runs along the lower reaches of the Don and the Volga delta. In Siberia and the Far East, the osprey can be found up to the southern border of the country.
In Russia, a predator often chooses the banks of water bodies surrounded by old trees (pines) with dried tops as a place of residence. He likes swampy sparse forests and vast lakes with clear shallow water, rivers with rifts and reaches. Does not shy away from sea coasts and islands. Nesting places are mainly limited to the forest zone, although birds can also settle outside it – in the floodplain forests of the steppes. On migration they can be found in open steppe areas. In the southern woodless areas, settled ospreys build nests on the rocks of the sea coasts, on coastal islands and even in small seaside towns.
Now you know where the osprey fisher is found. Let's see what it eats.
What does an osprey eat?
The osprey's diet consists of fish by 99%. Since this predator grabs prey from the fly, any species that have a habit of rising to the surface of the water become its prey.
As an exception, they catch other animals of a suitable weight, swimming and not swimming:
- water snakes;
- suitable sized amphibians;
- small crocodiles;
During the hunt, the osprey slowly flies above the water at a height of 10 to 40 m. Having found the target, the bird freezes for a moment, then rushes forward, holding outstretched claws in front of its beak. It can dive to a depth of 1 m (according to other sources, up to 2), but more often it simply plows the surface of the water with its claws. Having picked up the prey, the osprey carries it away, holding it with both paws, in order to eat in a calm environment or feed a partner on the nest.
Peculiarities of character and lifestyle
In southern regions with warm winters and non-freezing water bodies, ospreys live sedentary, and where winter fishing is impossible, they become migratory birds. From North America they fly to South, from Europe – to Africa, from the north of Asia – to the south and southeast of Asia. They depart south from September to October, returning in April – May.
Sedentary birds, free from family concerns, can also wander, making flights for food for several hours. Usually further than 10-14 km they do not fly away from their place of residence. The “language” of the osprey is rather poor. Basically, these are a series of meek sonorous calls, varying in tone and duration.
Interesting fact: These predators prefer fish 150-300 g, the record weight of prey is 1200 g. The length of the fish is 7 – 57 cm. In order to eat, a bird needs 300 – 400 g of food per day, according to other sources, it takes up to 800 g.
The mortality of young birds under the age of 2 years is high – an average of 40%. The main reason for the death of young animals is the lack of food. But ospreys can live for a long time – 20 – 25 years. In 2011, a record of longevity was recorded – 30 years, in 2014 – 32 years… Perhaps this is not the limit.
Social structure and reproduction
In different parts of the vast range, the mating season begins at different times. Sedentary birds start building nests in December-March, migratory — in April – May. Ospreys fly to nesting sites on their own, although they are monogamous and keep permanent pairs for many years. Males arrive first, females arrive a few days later.
In the forest zone, ospreys make nests on the dry tops of large trees, on high-voltage power line supports, towers for various purposes, and artificial platforms that are offered to them by conservationists. When choosing a place, they provide for the proximity of a good reservoir, so that it is no further than 3-5 km. Sometimes they build nests above the water.
The distance between nests ranges from 100 m to several kilometers. Usually each family settles away from the others, but colonies are formed near especially fish ponds. The nest is made of twigs, algae or grass are used for decoration, moss – whatever you can find. Sometimes there are fishing lines or plastic bags. Nests serve as one permanent pair for many years, each season they are updated and completed.
Before marriage, the male leks, flying in circles over the nest where the female sits. It emits a series of calls, flies up, flutters its wings and holds a gift fish in its paw. After 10 minutes, deciding that he tried hard enough, he flies to the nest to his lady. When the wife begins to incubate the eggs, the male brings her food and can take part in incubation. Adultery happens when the male does not bring enough food and the hungry female is forced to turn to others. Or the male starts working for two families if the nests are located nearby.
Eggs are from 2 to 4, the color is white with brown spots. The birth of chicks occurs after 38 – 41 days. With a lack of food, not all chicks survive, but only those that hatched first. For two weeks, the female warms them constantly, then less often, devoting time to getting food. The young fledge after 1.5 – 2.5 months and can hunt on their own, although they still try to beg for food from their parents for a long time. For the winter, everyone flies on their own. Ospreys become sexually mature by 3 — 5 years and young years are spent “abroad” – in wintering places.
An interesting fact: in Australia, nests have been registered that have been used for 70 years. They are built on coastal rocks and are huge piles of snags and branches braided with algae, reaching 2 m in height, 2 m in width and weighing 135 kg.
Natural enemies of the osprey
Even such a large predator there are enemies. These are even larger predators – eagles, which displace the osprey, competing with it for food and places to build nests. And those that operate under the cover of darkness – owls and eagle owls, who prefer to carry off their chicks.
Nest-ravaging land animals include:
- small climbing predators;
- crocodile. He catches the osprey in the water as it dives.
Naturally, a person also fell into the number of enemies, although not on purpose. It turned out that ospreys are very sensitive to pesticides, especially DDT and its derivatives, which used to be at a premium. These chemicals entered their bodies through the fish and caused the thinning of the egg shell and the death of the embryos, and as a result, a decrease in the birth rate. Adult birds also perished. Between the 1950s and 1970s, the number of breeding pairs on the Atlantic coast of the United States decreased by 90%, and on the Chesapeake Bay there were half as many. In Europe, in a number of countries (in the Pyrenees, in England, Ireland, France), ospreys have completely disappeared.
The number of ospreys is also negatively affected by intensive land development: deforestation, fishing, pollution of water bodies. Hunters contribute, those who love to destroy nests and simply show unhealthy curiosity.
Interesting fact: Osprey populations in Ireland disappeared by the beginning of the 19th century, they did not disappear in England in 1840 in Scotland in 1916. The reason for the destruction was the massive interest in collecting eggs and stuffed animals. The foolish infatuation passed, and migratory ospreys began to populate the islands again. In 1954 they bred again in Scotland.
Population and species status
In the latest IUCN Red List, the osprey has the status of a species of increasing abundance. The world population is estimated at 100 — 500 thousand individuals. Indeed, conservation measures (banning the use of “long-playing” pesticides and shooting birds of prey) have led to a noticeable increase in the number of birds on all continents. In Europe, where the situation was most difficult, the surviving populations in Scandinavia and Germany increased. Birds returned to England, Scotland, Bavaria, France. According to foreign data for 2011 — 2014 in Great Britain there were 250 – 300 residential nests, in Sweden 4100, in Norway – 500, in Finland – 1300, in Germany – 627, in Russia – 2000 – 4000.
In the Red Book of Russia, the species has status 3 (rare). According to the data given in it, most of the nests (about 60) are in the Darwin Reserve (Vologda region). There are several dozen pairs in the Leningrad and Tver regions, on the Kola Peninsula and in the lower reaches of the Volga. Less than ten pairs live in the Nizhny Novgorod region and in the rest of the Non-Black Earth region. In Siberia, small nesting sites were noted in the north of the Tyumen region and the south of the Krasnoyarsk Territory, most of all these predators (about 500 pairs) live in the Magadan and Amur regions, Khabarovsk Territory, Primorye, Sakhalin, Kamchatka and Chukotka. No more than 1,000 pairs in total across the country.
According to international experts in the field of conservation, this species has good prospects for survival, its future does not cause concern. But do not lose vigilance. The osprey remains under protection in Europe, North America and Australia, where all its populations are recorded and monitored. Programs have been developed to reintroduce birds to places where they were once destroyed (for example, in Spain).
It is included in the CITES list, which prohibits international trade in this species, applications of the Bonn and Berne conventions. There are international agreements on the protection of migratory birds that Russia has concluded with the United States, Japan, India, and Korea. The osprey is listed in the Red Book of Russia and Russian regional books of all areas where it lives.
Proposed protection measures are simple:
- preservation of habitats;
- installation of platforms for nests;
- relocation of nests from power transmission towers, where they arrange short circuits;
- creation of “quiet zones” around nests within a radius of 200-300 m;
- cleaning up water bodies;
- increasing fish stocks.
Today, the osprey is safe, not in danger, and in places its numbers are steadily increasing. This gives us hope that the ancient and majestic predator will remain with us for a long time. The realization that we are not alone on the planet slowly but surely reaches every person. And the results of the actions taken confirm that there is always an opportunity to change the situation with the extinction of a species for the better. Almost always.