glaucous gulls

The glaucous gull (''Larus hyperboreus'') is a large gull, the second-largest gull in the world. It breeds in Arctic regions of the Northern Hemisphere and winters south to shores of the Holarctic. The genus name is from Latin ''larus'', which appears to have referred to a gull or other large seabird. The specific name ''hyperboreus'' is Latin for "northern" from the Ancient Greek ''Huperboreoi'' people from the far north "Glaucous" is from Latin ''glaucus'' and denotes the grey colour of the gull. An older English name for this species is burgomaster.

This gull is migratory, wintering from in the North Atlantic and North Pacific Oceans as far south as the British Isles and northernmost states of the United States, also on the Great Lakes. A few birds sometimes reach the southern USA and northern Mexico.

Description

This is a large and powerful gull, second-largest of all gull species and very pale in all plumage, with no black on either the wings or the tail. Adults are pale grey above, with a thick, yellow bill. Juveniles are very pale grey with a pink and black bill. This species is considerably larger, bulkier, and thicker-billed than the similar Iceland gull, and can sometimes equal the size of the great black-backed gull, the oft-titled largest gull species. In some areas, glaucous gulls are about the same weight as great black-backed gulls or even heavier, and their maximum weight is greater. They can weigh from , with the sexes previously reported to average in males and in females. At the colony on Coats Island in Canada, the gulls are nearly 15% heavier than some other known populations, with a mean weight in five males and in seven females. One other study claimed even higher weights for glaucous gulls, as on Wrangel Island, 9 males reportedly averaged and in six females, which if accurate, would make the glaucous gull the heaviest gull and shorebird in the world if not (as far as is known) the largest in length on average.Dementiev, G. P. and N. A. Gladkov. (1951). ''Ptitsi Sovietskogo Soyuza irds of the Soviet Union'. Vol. 2. Israel, in 1968.]: Publishing House Sovietskaya Nauka, Moscow, USSR. [English translation by the Israel Program for Scientific Translations, Jerusalem.Weiser, Emily and H. Grant Gilchrist. (2012). ''Glaucous Gull (Larus hyperboreus)'', The Birds of North America (P. G. Rodewald, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America: https://birdsna.org/Species-Account/bna/species/glagul. DOI: 10.2173/bna.573 These gulls range from in length and can span , with some specimens possibly attaining , across the wings. Among standard measurements, the Wing chord (biology), wing chord is , the Beak, bill is and the Tarsus (skeleton), tarsus is . They take four years to reach maturity.

The call is a "laughing" cry similar to that of the herring gull, but deeper.

Subspecies

The four recognized subspecies are:

* ''L. h. hyperboreus'', Gunnerus, 1767: nominate, found from northern Europe to north-western Siberia
* ''L. h. pallidissimus'', Portenko, 1939: found from north-western Siberia to the Bering Sea
* ''L. h. barrovianus'', Ridgway, 1886: found from Alaska to north-west Canada
* ''L. h. leuceretes'', Schleep, 1819: found from north-central Canada to Greenland and Iceland

Ecology

This species of seagull breeds colonially or singly on coasts and cliffs, making a lined nest on the ground or cliff. Normally, two to four light brown eggs with dark brown splotches are laid.

These are omnivores like most ''Larus'' gulls, and they eat fish, insects, molluscs, starfish, offal, scraps, eggs, small birds, small mammals, and carrion, as well as seeds, berries, and grains.

File:Grote burgemeester eerste winter-4961707.webm, Glaucous gull at De Cocksdorp, Netherlands
File:Larus hyperboreus-USFWS.jpg,
File:Larus hyperboreus MWNH 0347.JPG, Egg, collection Museum Wiesbaden
File:Glaucous Gull flying with Great Black-backed Gulls.jpg, In flight with great black-backed gulls, Ottawa, Ontario

References

External links

Glaucous gull
, Alaska Seabird Information Series
*
*
*
*
*
*
*

{{Taxonbar, from=Q27375

Larus
Birds of the Arctic
Birds described in 1767
Taxa named by Johan Ernst Gunnerus
Articles containing video clips
Holarctic birds