Bering Gull
| Bering Gull | ||||||||||||
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Adult bering gulls |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Larus glaucescens | ||||||||||||
| Nauman , 1840 |
The Bering Gull ( Larus glaucescens ) is a large, monotypical species within the seagull . The IUCN classifies the Bering Gull as 
(= Least Concern - not endangered) and estimates the population at 570,000 sexually mature individuals.
Appearance
The Bering Gull reaches a body length of 58 to 63 centimeters. The wingspan is 130 to 160 centimeters. The weight varies between 850 and 1,700 grams.
In breeding plumage Bering seagulls have a white head. The beak is yellow with a red-orange spot at the tip of the beak. The inside of the beak is pink to purple-pink. The eyes are small in relation to the body size and dark in color. The eye ring is pink to reddish. The coat and back are medium gray with a slightly bluish tone. The trunk and tail are white. The underside of the body is also white. In the plain dress , the head, the neck and the front breast are dashed in brown. The beak is then dull yellow, the orange beak spot is usually missing. Although no subspecies are distinguished, the breeding birds of Siberia are generally a bit darker on the upper side of the body and have slightly longer wings.
Young birds are gray-brown, the trunk and upper and lower tail-coverts are somewhat paler. The feathers of the coat are lined with lighter colors, which gives the young birds a slightly scaled appearance. The beak is black. Bering gulls only have adult plumage when they are four years old. The downy chicks are reddish light brown with dense dark spots on the upper side of the body.
Distribution area
The Bering Gull breeds on the shores of the Bering Strait . The breeding area includes the south and west of Alaska, the south of the Chukchi Peninsula , Kamchatka and the Commander Islands . It seldom breeds inland. The Bering Gull is a partial migrant and occurs in the winter months on the North American coast as far as Baja California and on the Asian coast as far as Japan .
Way of life
The Bering Gull eats invertebrates, fish, young birds and eggs. It is one of the main predators of the alkenbirds , eats their eggs and, among other things , hunts for the young birds of the yellow cap , pigeon duck , dwarf lalk , bearded lalk , Aleutian lalk and red- beaked lalk . It also eats carrion. In Siberia, she is known for following walrus hunters to eat the innards of the animals they hunt . Furthermore, cases are known in which the gulls accompany Kodiak bears on their fishing trips in order to consume the resulting fish carcasses and their spawn.
The Bering Gull occasionally breeds solitary, but usually in small colonies. It enters into a monogamous pair bond, but it regularly mates with other conspecifics. The nest is built on the bare ground and made of seaweed. The actual nesting trough is covered with grass and feathers. The clutch usually consists of two or three eggs. These are pale green or olive in color and have dark, brown spots. The breeding season is 26 to 29 days. Both parent birds breed and are involved in rearing the chicks. The chicks are fledged after 37 to 53 days. Bering gulls breed at the earliest when they are four years old.
supporting documents
literature
- Richard Sale: A Complete Guide to Arctic Wildlife , published by Christopher Helm, London 2006, ISBN 0-7136-7039-8
Web links
- BirdLife factsheet on the Bering Gull
- Larus glaucescens inthe IUCN 2013 Red List of Threatened Species . Listed by: BirdLife International, 2012. Retrieved January 14, 2014.
Single receipts
- ↑ BirdLife Factsheet on the Bering Gull , accessed December 19, 2010
- ↑ Sale, p. 244
- ↑ Sale, p. 245
- ↑ Sale, p. 244
- ↑ F.Goethe: Seagulls and Alken . In: Prof. Dr. Bernhard Grzimek (ed.): Grzimeks animal life birds . tape 2 . Bechtermünz, Augsburg 2000, ISBN 3-8289-1603-1 , p. 213 .
- ↑ Sale, p. 245