Red-legged Kittiwake
Red-legged Kittiwake
Rissa brevirostris
At a Glance
This small gull is an uncommon specialty of the Bering Sea, nesting in only four island groups. Its limited range is surprising because its close relative, Black-legged Kittiwake, is abundant in northern waters; even in the general region of the North Pacific and Bering Sea, Black-legged outnumbers Red-legged by more than ten to one. Red-legged Kittiwake is known to birders mainly from colonies on the Pribilof Islands, Alaska.
All bird guide text and rangemaps adapted from by Kenn Kaufman漏 1996, used by permission of Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Category
Gull-like Birds, Gulls and Terns
IUCN Status
Vulnerable
Habitat
Coasts and Shorelines, Open Ocean
Region
Alaska and The North
Behavior
Direct Flight, Hovering
Population
200.000
Range & Identification
Migration & Range Maps
Movements not well known; may winter in Gulf of Alaska and near edge of pack ice in Bering Sea. Almost never occurs south of Alaska, but one was found once in summer in southern Nevada.
Description
14-15 1/2" (36-39 cm). Much like Black-legged Kittiwake but has shorter bill, steeper forehead, much darker wings (so that black tips contrast less), red legs and feet. Immatures like young Black-legged but lack black tail band, have darker forepart of wings.
Size
About the size of a Crow
Color
Black, Gray, Red, White, Yellow
Wing Shape
Long, Narrow, Pointed, Tapered
Tail Shape
Notched, Short, Square-tipped
Songs and Calls
Less vocal than Black-legged Kittiwake, calls higher pitched.
Call Pattern
Flat, Rising
Call Type
Scream
Habitat
Ocean, islands. At sea found mostly over deep water, at and beyond edge of continental shelf. May forage farther from nesting colonies than Black-legged Kittiwake. Especially in winter may be very far from land, in North Pacific or near edge of pack ice in Bering Sea. Nests on ledges of steep cliffs above sea on islands.
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Behavior
Eggs
One, sometimes two. Variable, gray to buff or greenish, with blotches or scrawls of brown. Incubation by both sexes, probably about 30 days; may incubate slightly longer than Black-legged Kittiwake on Pribilofs.
Young
Both parents care for young, brooding them for first two weeks after hatching, feeding them by regurgitation. Young capable of flight at about 37 days; may return to nest to be fed for at least several more days.
Feeding Behavior
Forages by dipping to surface of water or plunging into water from flight low over surface. Often forages in flocks, mixed with Black-legged Kittiwakes, over schools of fish. Red-legged Kittiwake has larger eye, possibly adaptation to feeding in dim light; may feed by day or night. Some food items such as lampfish and squid may be closer to surface at night.
Diet
Fish, squid, crustaceans. Feeds mainly on lampfish, pollack, squid, and small crustaceans such as amphipods. Fish eaten are mostly under 4" long.
Nesting
Breeds in colonies, associated with other seabirds. Courtship displays similar to those of Black-legged Kittiwake. Nest site is on ledge of vertical cliff, often smaller ledges than used by Black-legged Kittiwake. Nest (built by both sexes) is shallow cup of mud, grass, kelp. Same site may be re-used each year, although nest must be rebuilt after effects of winter storms.
Conservation
Conservation Status
Total population in 1970s estimated at a little over 230,000, with 95% of these in Pribilofs. Since then, evidence of major declines in Pribilofs, small increases at some other colonies. Decline probably related to unreliable food supply, but causes for this not well known. Also vulnerable to accidental introduction of rats to nesting islands. May have been much more numerous historically, but no reliable data.