Rissa brevirostris (Bruch, 1855)

Taxonomy and Range

The red-legged kittiwake, scientific name Rissa brevirostris (Bruch, 1855), is a very localized seabird species native to the subarctic Pacific.

Distinguishing Leg Feature

It is very similar to its better-known relative, the black-legged kittiwake, with the most obvious distinguishing feature noted in its common name: red legs.

Adult Morphological Differences

Other differences between the two species include the red-legged kittiwake’s shorter bill, larger eyes, larger rounder head, and darker gray wings.

Juvenile Plumage Traits

Juvenile red-legged kittiwakes barely differ in appearance from adult red-legged kittiwakes; they lack the black tail band and distinct "W" marking across the wings that mark juvenile black-legged kittiwakes.

Maturation Period

Red-legged kittiwake juveniles take three years to reach full maturity.

Adult Size and Weight

Adult red-legged kittiwakes measure 35–39 cm (14–15 in) in body length, have a wingspan of 84–92 cm (33–36 in), and weigh 325–510 g (11.5–18.0 oz).

Hind Toe Characteristics

Like the Pacific race of black-legged kittiwakes, red-legged kittiwakes have a well-developed hind toe.

Sighting Reporting Requirements

Because occasional individual black-legged kittiwakes naturally have reddish legs, bird recording authorities will only accept records of red-legged kittiwakes seen outside the subarctic Pacific if the report documents all the other species-specific differences, not just leg color.