L. g. kumlieni
|Larus glaucoides kumlieni|
Kumlien's gull (Larus glaucoides kumlieni) is a large gull which breeds in the Arctic regions of Canada. It is migratory, wintering from Labrador south to New England and west across the Great Lakes. The species is named after the Swedish-American naturalist Thure Kumlien. It is a regular vagrant in small numbers to Britain and Ireland.
It has variably been considered a full species, a subspecies of Thayer's gull, a subspecies of Iceland gull, and a hybrid between the aforementioned species, all of which are considered subspecies of the Iceland gull as of 2017.
This taxon breeds colonially or singly on coasts and cliffs, making a nest lined with grass, moss or seaweed on the ground or cliff. Normally, 2-3 light brown eggs are laid.
The taxon is pale in all plumages, with a remarkably variable amount of pigment in the primaries. Individuals range from completely white-winged (indistinguishable from nominate glaucoides Iceland gull) to so dark in the wings as to be indistinguishable from Thayer's gull. Eye color is also variable, from pale yellow to dark brown. Such remarkable variation seems to lend credence to the belief that Kumlien's gull is in fact a hybrid swarm.
Kumlien's gulls average smaller overall and much smaller-billed than the very large glaucous gull and are usually smaller than herring gull. The taxon reaches adult plumage in four to five years. The call is a "laughing" cry like the herring gull's, but higher pitched.
These are omnivores like most Larus gulls, and they will scavenge as well as seeking suitable small prey. These birds forage while flying, picking up food at or just below the water's surface, also feeds while walking or swimming. Their scavenging habits lead them to frequent garbage dumps, sewage outlets and places where fish are cleaned.
- Kaufman, Ken. "Goodbye Thayer's Gull, Hello Cassia Crossbill: This Year's Changes to the Official List of North American Birds". Audubon. Retrieved 7 March 2018.
- Seabirds by Harrison, ISBN 0-7470-1410-8
- Bull, John; Farrand, Jr., John (April 1984). The Audubon Society Field Guide to North American Birds, Eastern Region. New York: Alfred A. Knopf. ISBN 0-394-41405-5.
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