Rissa tridactylablack-legged kittiwake

Last updated:

Geographic Range

In North America, the Black-legged Kittiwake spans both coasts, as far north as the ice-free waters of Alaska in the west and the Great Banks of Newfoundland in the east. It lives as far south as Baja, California in the west and the tip of Florida in the east. Outside of America it can be found in nearly every coastal area of the world, given the proper habitat is available. This includes the coast of Norway, Britian, France, and the former Soviet Union, along with China, Japan, Korea, Central Europe, and nw. Africa.

Habitat

The Black-legged Kittiwake nests on ledges of offshore islands, sea stacks, or inaccessible areas of coastal mainland. It also nests on steep earthen slopes, large boulders, glaciers, and cliff-like man-made structures, such as shipwrecks and skyscrapers. A true shoreline species, it rarely comes very far inland, even in the winter.

Physical Description

The Black-legged Kittiwake is a small gull, with a pearl gray back and wings and a stark white head and underside. The tips of the tail feathers are black. The adult bill is uniformly greenish-yellow. In spite of its name, its legs can be orange or red, although they are most commonly black.

  • Average mass
    317 g
    11.17 oz
    AnAge

Reproduction

Pairs are generally monogamous, although males attempt to mate with other partners. In a study done in Britian, 64% of pairs remained together from one breeding season to the next. Due to their global distribution, it is difficult to give precise copulation, incubation, and hatching dates for kittiwakes. Black-legged Kittiwakes nest on cliffs, and the male retains the same nest site from year to year. After the nest is ready, 1 to 3 eggs are laid. The male and female incubate the eggs for about 25 days. At this time the chicks hatch. The parents seem to share the responsibilities for the chicks evenly, with both sexes feeding and brooding the young.

  • Average eggs per season
    2
    AnAge
  • Average time to hatching
    27 days
    AnAge

Lifespan/Longevity

Behavior

With a tern-like wingbeat the Black-legged Kittiwake is highly manueverable. It is able to land on narrow ledges in strong winds. It nests in interspecific colonies, with 51 to 57 cm between nests.

Communication and Perception

Food Habits

Unlike many gulls, the Black-legged Kittiwake does not feed at dumps. Rather, it feeds on the water surface. An opportunistic feeder, it feeds on small surface fish and invertebrates. It prefer fishs, and the species consumed most often are capelin, sandlance, arctic cod, pollock, saffron cod, small trout, and young salmon.

Conservation Status

Although there is no special status for the Black-legged Kittiwake, fishing poses a possible threat to population size. As fish stocks decline along coastal areas, species that are kittiwake prey are being harvested. This may lead to disasterous effects on the population of kittiwakes, which often depending largely on one major source for food.

Other Comments

The Black-legged Kittiwake has many adaptations to nesting on vertical sea cliffs, including facing towards the cliff, so that their tails project over the edge and their feet are on solid ground.

Contributors

Jennifer Roof (author), University of Michigan-Ann Arbor.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

World Map

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

coastal

the nearshore aquatic habitats near a coast, or shoreline.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

oriental

found in the oriental region of the world. In other words, India and southeast Asia.

World Map

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

visual

uses sight to communicate

References

Baird, Pat Herron. The Birds of North America. No. 92, 1994. The American Ornithologists' Union.