Steinstrandläufer

Bestimmung

Adults have short yellow legs and a medium thin dark bill. The body is dark on top with a slight purplish gloss and mainly white underneath. The breast is smeared with grey and the rump is black. The Pribilof Islands subspecies of this bird shows a bold black belly patch.

Taxonomie

The rock sandpiper was formally described in 1873 by the American ornithologist Elliott Coues and given the binomial name Tringa ptilocnemis. It was formerly placed in the genus Erolia, but is now placed with 23 other sandpipers in the genus Calidris that was introduced in 1804 by the German naturalist Blasius Merrem. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific epithet ptilocnemis combines the Ancient Greek ptilon meaning "feather" with knēmē meaning "leg". Within the genus Calidris the rock sandpiper is closely related to the sanderling (Calidris alba) and dunlin (Calidris alpina) and is sister to the purple sandpiper (Calidris maritima).<p>Four subspecies are recognised:

Wissenschaftlicher Name

Calidris ptilocnemis

Autorität

(Coues, 1873)

Ordnung

Regenpfeiferartige

Familie

Schnepfenvögel (Scolopacidae)

Gattung

Calidris

Verbreitung und Lebensraum

Birds migrate south to rocky ice-free Pacific coasts in winter. The subspecies leap frog each other for winter, with more northerly breeders passing south of more southerly breeders. It reproduces in tundra habitats, typically favoring drier and more desolate areas with limited vegetation such as lichen, moss, and sparse grasses. It can form rather large wintering flocks.<p>Rock Sandpipers which spend the non-breeding season in the Pacific Basin, Alaska, have to endure harsh conditions where they rely on high prey quality, especially of their primary prey - the bivalve Macoma balthica.

Brutgebiet

PAL, NA : coastal low Arctic to subarctic tundra of far n Pacific: e Chukotskiy Pen. to (disjunctly) s Kamchatka, Commander and (perhaps) n Kuril is. (e Russia), Aleutian and Bering Sea is., w Alaska from Seward Pen. to Gulf of Alaska is.

Überwinterungsgebiet

rocky subarctic to temperate coasts: Hokkaido (n Japan, w North Pacific; rare) to c California (e North Pacific)

Zugverhalten

Complete migrants

Verhalten

Their breeding habitat is the northern tundra on Arctic Pacific coast of Alaska and the Aleutian and Pribilof Islands. The birds also breed in Kamchatka and the Kuril Islands. The breeding pair is usually monogamous, with pair bonds usually lasting several years. They nest on the ground either elevated on rocks or in lower damp location. The male makes several scrapes; the female chooses one and lays 4 eggs. Both male and female take the responsibility for incubation.<p>These birds forage on rocky coasts. They mainly eat insects, mollusks, marine worms, also some plant material. It often feeds up to its breast in water, and often swims. It roosts on rocks near its feeding grounds just above the high tide spray.

Schutzstatus

Bestandstrend

declining