Dominican gull
| Dominican gull | ||||||||||||
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Dominican gull ( Larus dominicanus ) |
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| Scientific name | ||||||||||||
| Larus dominicanus | ||||||||||||
| Lichtenstein , 1823 |
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The Dominican gull ( Larus dominicanus ) is one of the larger gull species with a body length of up to 58 centimeters and a wingspan of 125 cm . It has white plumage on its head, neck, underside and tail, while the upper wings and back are black. The name of the seagull is derived from this color and goes back to the habit of the Dominicans . The beak is yellow with a red spot on the lower beak. The color of the feet ranges from yellow to olive green. In the Southern Oceans, the Dominican gull is the only large species of gull that has a white head and tail. From a distance it can only be confused with the black-billed gull , which is considerably smaller and has a bright red beak.
distribution
The distribution area of the Dominican gull extends from the coasts of South America to South Africa , New Zealand and many sub-Antarctic islands in the southern ocean belt. The Dominican gull is also the only species of gull that breeds on the Antarctic Peninsula. In November or December the seagull lays two or three speckled eggs in a nest made up of plant parts, bones and snail shells. The young hatch after a breeding period of four weeks and are fledged after another six to eight weeks.
nutrition
Dominican gulls feed primarily on limpets and the waste from other bird colonies. They also eat the rubbish found in human settlements. The food spectrum of the Dominican gulls also includes fish, small mammals, birds up to the size of a goose and sickly lambs, as well as the afterbirth of sea lions. At sea, Dominican gulls occasionally follow boats to eat their waste. They also hunt down Sterna species for food.
In the last 30 years, Dominican gulls have started to feed on the southern capers off the Argentine peninsula of Valdés . Initially, the seagulls landed on the whales and pecked parasites and loose bits of skin. At some point, however, the Dominican gulls started pecking healthy pieces of meat from the whales. In the meantime, the seagulls have become a nuisance for the whales that raise their offspring in the region. The whales dive much more often than usual to get away from the seagulls and thereby waste a lot of energy; especially the whale mothers would need a lot of rest to raise their calves. In addition, the gulls concentrate on the whale mothers and their calves, which have to come to the surface much more often than the other whales.
On Guafo Island , the seagulls also feed on hookworms from the droppings of the pups of the South American fur seals ( Arctocephalus australis ), which live as parasites in the intestinal tract of these animals. They sometimes pick up the worms and the bloody stool while defecating the anus of the seal pups and regularly inflict sometimes severe wounds, which often lead to infections of the seals' anal region.
Reproduction
The breeding season of the Dominican gulls usually falls between September and January. It forms dense and occasionally very large colonies. Sometimes it is associated with the black-billed gull. Dominican gulls that breed individually are also regularly observed.
The nest is built from dried plants and algae. It is often found at the base of a shrub or boulder. The clutch usually consists of two to three eggs. These are incubated for a period of 24 to 30 days. The fledglings fledge at around seven weeks of age.
supporting documents
literature
- Hadoram Shirihai: A Complete Guide to Antarctic Wildlife - The Birds and Marine Mammals of the Antarctic Continent and Southern Ocean , Alula Press, Degerby 2002, ISBN 951-98947-0-5
Web links
- Larus dominicanus in the endangered Red List species the IUCN 2008. Posted by: BirdLife International, 2008. Accessed on December 22 of 2008.
- Videos, photos and sound recordings of Larus dominicanus in the Internet Bird Collection
- Pictures of the Dominican gull on jostimages.de
- Feathers of the Dominican Gull
Individual evidence
- ^ Shirihai, p. 226
- ↑ sueddeutsche.de (June 26, 2009): Birds on whaling ( memento of the original from June 29, 2009 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
- ↑ BBC News (June 24, 2009): Gulls' vicious attacks on whales (photo series)
- ↑ Mauricio Seguel, Francisco Muñoz, Felipe Montalva, Diego Perez-Venegas, Héctor Pavés, Nicole Gottdenker: Kelp and dolphin gulls cause perineal wounds in South American fur seal pups (Arctocephalus australis) at Guafo Island, Chilean Patagonia. Royal Society Open Science, July 26, 2017 doi : 10.1098 / rsos.170638 .
- ^ Shirihai, p. 226
