Glaucous Gull (Larus hyperboreus) 1st-W - 2cy
Kilmore Quay, County Wexford
[order] Charadriiformes | [family] Laridae | [latin] Larus hyperboreus | [UK] Glaucous Gull | [FR] Goéland bourgmestre | [DE] Eismöwe | [ES] Gaviota hiperbórea | [IT] Gabbiano glauco | [NL] Grote Burgemeester
spanwidth min.: 138 cm
spanwidth max.: 158 cm
size min.: 63 cm
size max.: 68 cm
incubation min.: 27 days
incubation max.: 28 days
fledging min.: 45 days
fledging max.: 50 days
eggs min.: 2
eggs max.: 3
An inhabitant of the far north, the Glaucous Gull is a large, pale gull with a large bill. The adult appears very white. Its back and wings are light gray, and the wingtips are white, with no black on the wing. The tail is white. The legs are pink, and the eyes are yellow. The bill is yellow with a red spot. In the non-breeding season, the adult's head is streaked with brown. Birds in breeding plumage have pure white heads and fleshy yellow eye-rings. The Glaucous Gull may be confused with the Glaucous-winged Gull, with which it hybridizes. Like most of the large gulls, this is a '4-year gull,' meaning that it takes 4 years to reach adult plumage, with a different sub-adult plumage each year. Juveniles are mostly white with buff markings. The first-year plumage is distinguished from that of a Glaucous-winged Gull by the distinctly bi-colored bill with a dark tip and a flesh-pink base.
The Glaucous Gull usually associates with flocks of other roosting and feeding gulls such as Glaucous-winged and Herring Gulls. A predator and a scavenger, the Glaucous Gull will steal food from other birds. It forages while flying, walking, or swimming. In flight, it picks items off the surface of the water and may catch smaller birds.
The Glaucous Gull is the only large gull common in the high Arctic. It inhabits cold, coastal bays, estuaries, and offshore areas. In winter, Glaucous Gulls have been found on large inland lakes. Nesting habitat is mainly cliff ledges, islands, and beaches. Foraging habitat includes garbage dumps, fish-processing plants, harbors, mud flats, sewage lagoons, flooded fields, and fish-spawning areas.
Larus hyperboreus breeds in Greenland, Svalbard, Iceland and arctic Russia, with Europe accounting for less than a quarter of its global breeding range. Its European breeding population is relatively small (<140,000 pairs), but was stable between 1970- 1990. Although the trends of the populations in Iceland and Russia during 1990- 2000 were unknown, the species was stable in Svalbard and the stronghold Greenland, and hence probably remained stable overall.
In the New World Glaucous Gulls are widespread and common in the far north where they are protected from human activities due to the remoteness. High Arctic habitats are slow to rebound from degradation, and these areas should be protected to maintain the population at its current healthy level. Populations in the eastern Bering Sea hybridize with Glaucous-winged Gulls.
Glaucous Gulls eat fish and other aquatic creatures, as well as insects, birds, eggs, berries, carrion, and garbage.
This species has a large range, with an estimated global Extent of Occurrence of 1,000,000-10,000,000 km². It has a large global population estimated to be 200,000-2,000,000 individuals (Wetlands International 2002). Global population trends have not been quantified, but the species is not believed to approach the thresholds for the population decline criterion of the IUCN Red List (i.e. declining more than 30% in ten years or three generations). For these reasons, the species is evaluated as Least Concern. [conservation status from birdlife.org]
Pairs nest in colonies or alone on cliff tops, flat, rocky ground, ice, or snow. Both adults help build the nest, which is a mound of vegetation and miscellaneous debris, depressed in the center. Both incubate the 3 eggs for about 4 weeks. Both parents feed the downy chicks for close to 2 months. The young leave the nest on foot a few days after hatching, and they stay close to the nest until their first flight at 45-50 days, soon after which they become independent.
Migratory, partially migratory, or dispersive in different regions. East Greenland population migratory, believed to winter in Iceland. Resident in Iceland, where numbers much increased in winter. In Eurasia, winters as far north as coasts remain ice free, or refuse available. Present then, though in reduced numbers, on Jan Mayen and Spitsbergen; occurs (immatures predominating) on southern Novaya Zemlya except in winters of heavy ice formation; winters also in White Sea and on coasts of Murmansk and northern Norway. An abundant winter visitor to Faeroes, and reaches Britain and Ireland annually in variable numbers, usually rather small though in severe winters it can become almost common, especially in Scotland where a few aggregations of 80 or more have occurred. Timing of arrival in Britain also variable, according to weather conditions further north, and departures linked to late winter and early spring temperatures; few present before mid-October, and arrivals can continue into December. In mild seasons, departures begin late January or early February, though can be extended to mid-April.