Narrow-beaked warrior Picture

Narrow-beaked warrior of Boreus (Boreofregata acutirostra)
Order: Charadriiformes (Charadriiformes), suborder Gulls (Lari)
Family: Skuas (Stercorariidae)
Habitat: coast of Arctic Ocean.
Summer in northern polar latitudes is a continuous polar day. Sun shines all day and night, and it promotes development of plenty of plankton in top layer of oceanic water. Abundance of plankton involves unnumerable schools of fishes and cephalopods, which, in turn, are a food for various carnivores.
During the polar summer above ocean large long-winged birds appear. They promptly sweep above a surface of water, and by dexterous movement snatch fishes and squids from water. These birds are very similar to man-o-war birds (Fregata) of Holocene epoch, but such similarity is only external. These birds are descendants of skuas (Stercorarius), gulls known for predating bents. They make a separate genus of birds – warriors of Boreus (Boreus in ancient Greek mythology is a god of northern wind; this name emphasizes features of area of these birds in comparison with true man-o-war birds, which had dyed out at the boundary of Holocene and Neocene).
The most widespread species of these birds is narrow-beaked warrior of Boreus, the long-winged predatory bird living at the coast of Arctic Ocean in flights numbering up to one hundred of individuals. Feature of this species is long beak compressed from sides and having hooked tip. By such beak bird dexterously seizes prey from surface of water.
All warriors of Boreus are birds having magnificent flight abilities. Wings of narrow-beaked warrior of Boreus are very long; their wingspan makes about 200 cm. The tail of bird is V-like doubled and is a little similar to swallow’s tail. Such tail shape provides an excellent maneuverability to this bird. Despite of large wingspan, narrow-beaked warrior of Boreus weighs not so much: no more than one and a half kilograms.
The plumage of this bird has dark brown colouring, and only under tail and in the bottom part of stomach it has ochre-red color. Primarily feathers are black with metal shine. Colouring of beak contrasts with background of dark plumage as a bright spot – at sexually mature birds it is bright yellow with black spot on the tip. At not sexually mature birds beak has light brown color.
Narrow-beaked warrior of Boreus eats sea animals – fishes, squids and large swimming crustaceans. It never alights on water, because has no swimming membranes and is not able to swim. As against true man-o-war birds, at warriors of Boreus there is an advanced coccygeal gland, due to which the plumage of bird has water-repellent properties. Besides narrow-beaked warrior of Boreus is the masterly air hunter: it also eats small sea and ground birds. Having gathered full speed, this bird hurriedly forces down small birds by impact of beak, at once picks up them right in air, and swallows entirely. Narrow-beaked warrior of Boreus hunts not only in coastal zone of seas, but also above tundra and bushes. However, this bird does not fly in forest and does not fly low above bushes, being afraid to injure wings. It partly rescues small birds from this predator: they wait occurrence of such air hunter, having hidden in bushes. Large species of warriors of Boreus frequently get food using cleptoparasitism – they attack sea birds of other species had caught prey: gannetwhales and eagleravens. Striking to them impacts by beak and wings, warriors of Boreus compel victim to let out prey, and pick it on the spot.
As against true man-o-war birds, warriors of Boreus can walk on the ground, and even fly up from flat surface against a wind; but they never perch on trees.
Warriors of Boreus nest in pairs at some distance from each other. Only right after migration or before back migration they gather in big flocks. During the nesting period birds occupy the certain territories of about one hundred square meters, which borders are strictly protected. The alien bird has been late too long at the territory of pair risks to cause aggression of owners of this territory. In the centre of nested territory the nest is located; usually birds arrange it in shelter – among stones or under bushes. The reason of it is the vunerability of warriors of Boreus to frequent attacks of large predatory birds – sea eagleravens. Approaching of this predator causes instant common alarm, and warriors of Boreus surround predator by large flocks. They attack eagleraven, striking to it impacts by beak and wings, and compel it to leave vicinities of nesting area.
In clutch of these birds it may be two large eggs with spotty brown shell. They are hatched mainly by female, and male feeds her. The hatching lasts till about 43 days. Nestlings of warrior of Boreus hatch covered with down and having opened eyes. They have rather long wings, and sometimes nestlings support on them at walking. They eat fish and other sea animals, and later, from bi-monthly age, start to eat entirely small birds brought by parents. To the autumn young birds get juvenile plumage, and at the second year of life their colouring changes to adult one.
Warriors of Boreus belong to number of migrating birds. In summer narrow-beaked warrior of Boreus is fattened in rich by forage polar waters; for winter it departs to the south. Western populations migrate along the Atlantic coast of Europe, reaching up to Canary Islands; some individuals reach coast of New Azora. Populations from Northern Asia migrate along more difficult route: they fly up to Fourseas, and then make non-stop flight up to coast of Arabia and even up to the north of Zinj Land. East Asian populations migrate via Beringia to the north of Pacific Ocean and fly to the south up to Japan Islands.
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