Field signs.'s Much bigger than crows, more korotkohvostogo and dlinnohvostogo skuas. Adult birds are different from other skuas that the average elongated steering wide and curved, the ends of their deployed in the vertical plane, so that from afar looks handle on the tail. Some birds underdog with the neighbors lose these elongated feathers, in which case the difference may be hard beak blushed with dark-colored peak (from other skuas, he completely dark). Coloring is very changeable. The Birds Morfou dark and have the same key dark brown plumage. A bright morfy most pronounced in the form of the entire bottom of cheeks and throat to belly and including white, with a pleasant yellow on the neck and cheeks. For more options dark light morfy lower body may be more or fewer dark-brown pestrin, especially thick on the chest (often merge into a solid dark collar) and on the sides. Maybe all the dark bottom of the body, and only the cheeks and neck burovato yellow. Clear signs of external genital No, but a pair of female usually darker and heavier than males. Young monotone brown, with large individual variations in coloring, with more or less pronounced light pestrinami, bobbin bluish-gray, fingers and membrane black. They are easily confused with other young pomornikami due to the weak differences in appearance and in the form of a tail. Young medium skuas be distinguished by a heavy build, powerful beak and there were two bright spots on the underside of the wing - at the base of primary Makhov and under large body of makhovaya. Average steering young curved, just issued over the edge tail. Weight 520-920 g body length 65-78 cm wing 35,4-39,2 cm, the magnitude of 113-127 cm (Ryabitsev, 2001). When intraspecific contacts on the ground nesting (territorial demonstrations, conflicts, grooming) a voice signal is composed of a series of nasal sounds like "hheeee-heee-hee-he-he-he-he" or "nnyayayaya-nyayaya-nyaya-class-class - class-class ", published in the rolling flight with a rare, as if fitful, scoop raised V-figuratively wings, either on the ground when the bird severely inflates the chest and raises the wings. When anxiety - a short and soft" hev "or" age ". In exile predators - loud nasal unduliruyuschie cries like "Aia-ya-ya-ya ..." or "a-la-la-la-la ..." Podrosshie (flight) chicks publish plangent melodic quivering whistle (Ryabitsev, 2001).  Distribution. Widely distributed in central Siberia to the Arctic and podzonah typical tundra. Nature stay on polar islands, is unclear. Field of nesting in the Taimyr is mostly within the Arctic tundra and northern and central sub-bands typical tundra. Single birds wander far to the north, at the edge of the Arctic Ocean ice and sometimes deep in the mainland (Rogacheva, 1988).
Habitats. Typical Habitat - opened flat tundra (especially Primorsk). In the depths of the continent - flat, moss-slabobugorkovaya osokovaya tundra, usually hollow down to bolotu or lake (Vinokurov, 1971). In the Arctic tundra apparently prefers to take a low of slopes involved papulose-spotted tundroy with more closed vegetation (Vronsky, 1986). Phenology. Spring in a typical tundra (Purinskie Lake) is 9-12 June, in mid-June starts masonry. Otlet with Taimyr - in early September (Syroechkovsky, Rogacheva, 1980). Reproduction. Nest placed in any relatively flat ground. It's easy fossa without lining or vystlannaya grass, moss and lichens, sometimes quite profusely. In laying usually 2 eggs, often - just one. Coloring eggs is very variable, from ohristoy or light brown to dark olive, brown spots or dark brown, often - small and not very thick. The size of eggs 56-73 x 40-47 mm. Nasizhivayut male and female 25-28 days. Actively chase from the vicinity of the nest all air and ground predators. A man react in different ways. Most of the birds wary, as they would fly into the side of impeachment - in silence or with a troubled few shouts. Other dive, portraying the attack, and even trying to hit on the head lapami, arm or chest. Sometimes the bends - otbegayut from nests ssutulivshis (Ryabitsev, 2001). Nutrition. Pronounced miofag. The main feed Lemming (Rogacheva, 1988), also eats other small rodents, fish, eat chicks and eggs of other birds. Takes extraction have often gulls (Syroechkovsky, Rogacheva, 1980). The number of species varies dramatically depending on the number of lemming - osnvonogo feed in gnezdovoe time. In the last number of years of depression skua not breed or breed poorly, becoming a normal kind of rare or very rare (Rogacheva, 1988). References. |
