Bonaparte's Gull

Bonapartemöwe in breeding plumage

The Bonapartemöwe ( Chroicocephalus philadelphia, Syn Larus philadelphia ) is a monotypic species of the family of seagulls. It is a Nearctic type which has much resemblance to the black-headed gull, but is somewhat smaller. Your name carries the Bonapartemöwe honor of the French naturalist Charles Lucien Bonaparte, nephew of Napoleon Bonaparte.

The IUCN classifies the Bonapartemöwe as an uncritical ( least concern ) and estimates the worldwide stock at 260000-530000 mature individuals.

Appearance

The Bonapartemöwe reaches a body length of 28-30 centimeters. The wingspan is 90 to 100 centimeters. The weight varies 180-230 grams.

In breeding plumage the Bonapartemöwe has a dark gray or black head. The black coloring extends from the upper neck to the chin. The beak is black, the beak inside is bright orange - red. She has a very thin dark reddish eye ring, the iris is dark brown. Above and below the eye, there are two white crescent-shaped spots. The body top and the tail is white, the chest and the abdomen acts in some individuals over wash pink. The body top is blue-gray, the outer primaries have black tips. The legs are red.

In Plain dress the dark head cap is missing. Only in the amount of the ear have Bonapartemöwen a black, usually crescent-shaped spot. Another very small dark gray spot is in front of the eye. The skull looks dirty gray. The legs are pink in the plumage.

Young birds also have a dark ear patch, the skull and the neck are about to wash dirty - brownish. The body top is pale gray-brown. The Dunenküken are mottled black and brown.

In the distribution area, there is only a possibility of confusion with the Sabine's Gull. However, this has a forked tail.

Distribution area

The Bonapartemöwe breeds in southern Alaska, it is, however, on both the western and the northern coast rare. It is also a breeding bird of the Yukon Territory and comes from there up to the southern boundary of the Hudson Bay before. Their habitat is lakes within the forest belt.

The Bonapartemöwe is a migratory bird and pulls in the winter months to the East and West Coast of the United States. They also wintered at the Great Lakes.

Way of life

Brooding Bonapartemöwen primarily eat insects, catching them both in flight and pick from the ground or water surface. During the winter months fish and crustaceans play a greater role in the food spectrum. During this time Bonapartemöwen are very social birds.

They breed usually single, but occasionally occur also small breeding colonies. Proceed according to the current state of knowledge a monogamous marriage season. They build their nests in trees, which is very unusual for seagulls. The nest is made of small twigs, and is lined with moss and grass. They occasionally use nests from the previous year, which they then expand.

The nest usually consists of three eggs. These are reddish brown - olivaceous or brownish gray with brown spots. The incubation period is 22 to 25 days. Both parents are involved in the breeding birds. The young birds fledge at an age of about 35 days. Bonapartemöwen breed aged at least two years for the first time.

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