Arctic dive

The Arctic Dive ( Gavia arctica ), also called in Arctic Quebec Huart , is a Gaviidé of intermediate size, sometimes confused with the Plongeon huard.

Systematic position

This species of dive is one of the four visible ones in Europe. Its binomial name comes from Latin Gavia , quoted by Pline, indicating a marine Oiseau (perhaps of the kind Larus) and of the Arctic Greek arkticos meaning and indicating its distribution.

Subspecies

There were three subspecies before:

species Gavia arctica

subspecies Gavia arctica arctica (Linnaeus, 1758);
subspecies Gavia arctica pacifica (Lawrence, 1858);
subspecies Gavia arctica viridigularis Dwight, 1918.

But certain authors (zoonomen.net, avibase…) considering that Gavia arctica pacifica is a species with whole share, Gavia arctica is represented more only by two subspecies:

Gavia arctica arctica (Linnaeus, 1758);
Gavia arctica viridigularis Dwight 1918.

The Plongeon of the Pacific Gavia pacifica (Lawrence, 1858) does not comprise a subspecies. Note: the subspecies Gavia arctica arctica corresponds to the species Gavia arctica initially listed by Linnaeus before the creation of the subspecies.

Morphology

It is a bird almost as large as a Oie, measuring from 58 to 73 cm and weighing on average 2500 G for the females, and 3500 G for the males. Its scale varies between 105 and 125 cm.
Son tapering body and its black webbed legs, very behind of the body, are adapted to the propulsion in aquatic environment. The adults nicheurs resemble small a Plongeon huard, with the finer lines. Males and females have the gray head, a large black triangular spot on the throat, of the black and white bands on the side of the neck and the chest and the white belly. The back presents black and white bands on the upper part, and a Damier black and white on the side and the wings.
Le plumage of winter is duller, gray-brown dark on the back, slightly mottled, with the belly, the chin and before neck white. The nozzle, gray dark at the time of the Nesting, becomes clearer in winter. The tail is short and black. The nozzle is in the shape of dagger.

Behavior

Flight

Description of the flight

Its flight is flexible, it flies with the tended neck, the head slightly falling, the legs lengthened backwards. It uses also its wings to swim.

Migration

Food

This species, like all the dives, is piscivorous generally capturing its preys under water. It can plunge up to 6 m of depth. It nourishes Poisson S, but does not hesitate to supplement its food intake of various watery invertebrates. One even found Grenouille S in the stomach of a dead individual.

Reproduction

The life expectancy of this dive is 27 years. This species gains its surface of nesting, generally near a deep big lake, between March and May. The Arctic dive is a bird monogamist. It nidifie even close to a not very full of fish water level, not hesitating to carry out long flights to go over other sites of nourrissage. It builds its nest without particular care: it is a simple not very deep hole furnished with foam, grass and sheets, even left naked (the eggs are then laid with same the ground). This nest is in contact with water, on a small island or bank. The female lays between May and June generally two eggs brown-yellow with some spots brown-black on butt end. The Incubation is carried out by the two parents and lasts on average a month (from 28 to 32 days). After the blossoming, the chicks will profit from the parental care for two months, but they are able only to be nourished at the end of two weeks.

Cry

During the winter season and in flight, the Arctic dive is rather quiet. On the surface of nesting, it often launches - woueuh- sound. During the bridal parade, it pushes piercing howls resembling yaps (to hear its cry, to see on this page).

Distribution and habitat

One finds it during the season of nesting in all the circumpolar zones of the Eurasia and the continent of North America, on the level of the cold moderate latitudes in the Arctic. The zone of wintering is vaster, it extends to the south until the Péninsule from Low-California, the seas Noire and Caspienne, or the China Sea. This bird winters on often deep big lakes. It at sea is found the remainder of time, in the coastal areas. During the migration, one can see it inside the grounds.

Statute and safeguarding

This bird is protected in Europe. Even if its distribution remains rather stable, the population is in very Net decline in certain zones (in Finland for example). The eggs of the Arctic dive have an alarming rate of pollution, and the rate of reproduction does not manage any more to compensate for death rate. It is necessary to add to this problem the human pressure on the sites of nesting, which places this dive in a worrying situation. It is what pushed the European commission (Directive birds), the Convention of Bern (protection of the wild life), CMS (Convention of Bonn), the AEWA Accord on the conservation of the migrating water birds of Africa-Eurasia and US Migratory Bird Act to protect it.

Birdlife International describes the species like " vulnérable" in Europe. Although according to the estimates of this organization, the European population would include/understand from 51.000 to 92.000 couples in summer, and 17.000 wintering (Russia included), they also noticed the decline of population, in Russia in particular. The European Agence for the environment (AEE) it also declared the species vulnerable since 1994. This dive was indeed declared like:

" with surveiller" by Norway, Sweden and Finland
" in danger" by Latvia and extinct Lithuania
in Poland

AEWA class this species in the category B2c (vulnerable populations (more than 100.000 individuals but regarded as requiring a special attention because of a demonstration of a significant decline in the long run)) for the populations of the Europe and west of the Siberia, and in the category C1 (rather many and little threatened population) for those of the east of Siberia and the Caspian Sea.

IUCN class the Arctic dive in the " category; concern mineure" , its world population having been estimated between 130.000 and 2 individuals million, divided on a territory estimated at 10 million km ².

It is sensitive to the virus H5N1 of the Avian flu. (A case in Germany, confirmed at the beginning of July 2007)

The Arctic dive and the Man

The Dive of Pacique and the Arctic Dive had the practice, off Japan at the end of the winter, to fish small fish collectively, joining together them in a reduced surface in order to capture them more easily. This attracted larger predatory fish, than the Japanese fishermen could then capture in great number. With such a help, the fishermen gained in February - March sufficient money to live one year; this is why these dives were regarded as messengers of the skies. Nowadays, the decline of the dives in these areas and the adoption of novel methods of fishing made disappear these practices.

Philately

Many countries emitted stamps with the effigy of this bird (Finland in 1993, Sweden in 1986, Lithuania in 2005, Austria in 1999, Poland in 1964, Russia in 1976, and Mongolia in 1973)

See too

Photographs and vidéos

Gallery photo Flickr on Avibase
Gallery aves on the Arctic dive
Video IBC: G.a.arctica in plumage internuptial (Netherlands)

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