Grèbe with black neck

The Grèbe with black neck ( Podiceps nigricollis ) is a Oiseau of the family of the podicipédidés . It is most sociable of all the Grèbe S, but also that whose world population is most numerous.

Etymology

The word grèbe is used to indicate this kind of bird since at least the 16th century and would be of Savoyard origin.
L' expression with black neck refers to the color of its neck in summer, which distinguishes it from the other species of grèbes.
With regard to the Latin name, Podiceps comes from Latin podex , the tail and pes , the foot (here, legs). The word nigricollis comes from Latin Niger , black and parcel , the neck.

Morphology

Measurements

Grèbe with black neck has an intermediate size between the crested Grèbe and the castagneux Grèbe, it measures from 28 to 34 cm. Its wing has a 12,4-13,9 cm length for a total scale from 50 to 60 cm. Its nozzle generally makes 2-2,6 cm; it is longer in the male (generally more than 2,4 cm) that in the female (generally less than 2,3 cm. Its weight varies from 213 to 402 G.

General aspect

This bird has a finer and slightly turned up nozzle that his/her cousin, the Grèbe esclavon. This nozzle is, moreover, entirely black. Like all the grèbes, Grèbe with black neck has greenish legs positioned very behind of the body, which facilitates the stroke, and its toes are lobed. The eye is red in the adult.

Bridal plumage

For the period of reproduction, it is recognizable thanks to the russet-red burning one of its sides but also thanks to the tufts of gilded feathers which can be spread in ranges on the sides of its head. The red iris is very definitely visible on the entirely black bottom of the head. The neck and the back are also of a major black. The black cap of the head is bent often than at the others grèbes.

Plumage internuptial

The winter plumage is dull. The back, the back of the nape of the neck and the calote are black, the sides, the belly, the chest, the throat and the cheeks are of a more or less clear gray, but the bottom of the cheeks is white. On the level of the head, the black cap goes down low than the eyes, which distinguishes it from Grèbe esclavon at which the eye is the limit of the winter black cap.

Aspect of the youthful ones

The young people have cheeks gray-brownish, darker than the adults. Let us oisillons have the black head presenting of the lines and spots clearer, generally brownish, and a red zone dew without feathers between the eye and the nozzle. ;.

Behavior

Social behavior

More sociable than the others grèbes, it niche generally in colonies being able to reach a hundred couples, often in company of colonies of Black-headed gulls or Guifettes moustac S.

Flight

Because of position of its legs, very behind of the body, it is easier to him to swim than to go or take off. For this reason, it seldom flies apart from the periods of migration, and it will avoid to the maximum venturing on the banks.

In flight, it holds its tended neck and its a little hanging legs. Although the beat of the wings is fast, the flight is generally low and not very powerful.

Migration

Grèbe with black neck is migrating partial, because the populations of the south of Europe, Asia and the USA can be resident at the year. The South-African subspecies P. nigricollis gurneyi does not migrate at all.

The migratory birds nest from March to August on their site of nesting, then in August or September, they migrate towards the south. The European populations generally go towards the Black Sea or the Mediterranean; the American populations go in majority towards the south-western coasts of the Pacific or the Gulf of Mexico.

Of gregarious behavior during the migrations, this bird can form concentrations of hundreds of thousands of birds on the level of certain sites (for example on the Big lake Salted, Utah, the USA or in the south of the Caspian Sea).

Displacements are rather night on the American northern continent, but can be diurnal in Eurasia.

One deferred cases of erratic individuals far away from the usual sites, as in the Azores, in Hawaii, in Madeira or the Canaries. One also reported observations of this birds to El Salvador and the Costa Rica.

Food

Grèbe with black neck is nourished in summer of insects grabbed on the surface, but also of watery insects (adult and larvae), of tétards, small fish, molluscs and small shellfish captured while plunging and swimming under water. In winter, its mode is more strictly piscivorous. It swallows its preys under water, contrary to the castagneux Grèbe which consumes its preys on the surface.

Reproduction

The couples, which were formed on the sites of wintering, arrive on the sites of nesting about March or April. They start a bridal parade then: they draw up chest against chest, swim one around the other the body in extension, shake the head, and precipitate on the other couples to intimidate them.

The two parents build a formed nest of a heap of plants in decomposition anchored to the alive vegetation of the edge of water. The laying takes place between March and July. Male and female brood from 3 to 4 eggs white-bluish which will brown in contact with the plants in decomposition. The last eggs are sometimes abandoned after the blossoming of the two first, 20 to 21 days after the laying.

Let us oisillons are nidifuges and often transferred onto the back of their parents. They will be independent at the end of three weeks.

Voice

Grèbe with black neck emits trilles (bibibib) and whistles (houiiti) very acute in summer (to listen to its cry, to see on this page). In winter, it is generally quiet.

Distribution

There as follows exist three subspecies of Grèbes with black neck, distributed:

• Podiceps nigricollis californicus (Heermann 1854): winter of the West of the American Northern continent (starting from the south-west of Canada) as far as Central America (Guatemala)
• Podiceps nigricollis gurneyi (Roberts 1919): South of Africa
• Podiceps nigricollis nigricollis (Brehm, CL 1831): winter in the south-west of Europe, in East Africa and Asia (central and Eastern)

The IUCN estimates that the world population of this grèbe includes/understands from 3,9 to 4,3 million individuals.

Habitat

In summer, he attends the plans of fresh water of intermediate size, the mud tanks and Argilière S left with the abandonment - often in company of colonies of black-headed gulls. He prefers the water levels presenting an abundant vegetation on his banks and an abundant watery fauna. In winter one generally meets it in the lakes, the large ponds and on the Estuaire S but also on the marine Littoral. It often mingles with others grèbes during the wintering. On the American continent, one can find it on lakes hypersodic (salted Big lake, Mono Lake) where it will nourish exclusively Artémie S and of Diptère S of the family of the Ephydridae, because these lakes do not contain a fish.

Statute and safeguarding

Grèbe with black neck can be victim, at the wintering level of the populations at sea, pollution to hydrocarbons.

Regarded as protected in Europe by the European Agency for the environment (AEE) since 1994, this species was declared all the same threatened in Sweden, and vulnerable in Germany, Latvia and Lithuania.

According to International BirdLife, the European population (Russia included/understood) would include/understand from 53.000 to 96.000 couples. The most populations are in Russia (30 000 to 60.000 couples) and in Ukraine (10 000 to 16.500 couples). It seems that after a notable increase in the European populations between 1970 and 1990, one again witnesses a decline between 1990 and 2000, especially on the level of the populations of Central Europe (in Romania for example) and of the Baltic States.

This bird is placed in appendix II of the Convention of Bern (protection of the wild life) and of the AEWA (Accord on the conservation of the migrating water birds of Africa-Eurasia) since 2002. It moreover is more particularly protected in Great Britain since 1982 and by Migratory Birds Treaty Act.

AEWA distinguishes various populations. The American, European and North-African populations are classified of category C (not threatened, more than 100.000 individuals). Those of Asia (estimated at 25.000 individuals by the AEWA) are of category B1 (very vulnerable populations (between 25.000 and 100.000 individuals)). Those of the south of Africa are of category A2 (threatened populations (between 10.000 and 25.000 individuals)).

IUCN classified Grèbe with black neck in category LLC (minor concern) because of its large surface of distribution and its world population estimated at approximately 4 million individuals.

Philately

Several states emitted stamps with the effigy of this bird (see HTTP: /www.bird-stamps.org/cspecies/901400.htm some examples here): the islands Maldives in 1986, the Dominique and the Serbia-and-Montenegro in 2005 as well as the Belgium in 2006.

Bonds and references

Photographs and vidéos

• Video IBC: Adult P. nigricollis nigricollis nourishing youthful (Alicante, Spain) a
• Video IBC: Adult P. nigricollis nigricollis carrying a oisillon on its back (marsh of Aldomirovtsi, Bulgaria)
• Video IBC: two P. nigricollis californicus adult in plumage internuptial (Baylands Palo Alto, California, the USA
• Photograph gallery of P. nigricollis on Calphotos
• Beautiful photograph gallery of P. nigricollis on the site Aves
• Gallery of images of P. nigricollis on Animal Diversity
• Photograph gallery of P. nigricollis on the site African Bird Club
• Flickr Gallery on Avibase

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