Curlew sandpiper
The curlew sandpiper is a small wader that breeds on the tundra of Arctic Siberia.
It is strongly migratory, wintering mainly in Africa, but also in south and southeast Asia and in Australia and New Zealand. It is a vagrant to North America.
Taxonomy
The curlew sandpiper was formally described in 1763 by the Danish author Erik Pontoppidan under the binomial name Tringa ferrugineus. It 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 ferruginea is from Latin ferrugo, ferruginis, "iron rust" referring to its colour in breeding plumage. The curlew sandpiper is treated as monotypic: no subspecies are recognised. Within the genus Calidris the curlew sandpiper is most closely related to the stilt sandpiper.This species occasionally hybridises with the sharp-tailed sandpiper and the pectoral sandpiper, producing the presumed "species" called Cooper's sandpiper and Cox's sandpiper, respectively.
Description
These birds are small waders, similar to dunlin, but differ in having a longer down-curved beak, longer neck and legs and a white rump. They have a length of, weight of 44-117 g and wingspan of. The breeding adult has patterned dark grey upperparts and brick-red underparts. In winter, this bird is pale grey above and white below, and shows an obvious white supercilium. Juveniles have a grey and brown back, a white belly and a peach-coloured breast.Distribution and habitat
The curlew sandpiper breeds in the Siberian Arctic from the Yamal Peninsula to the Kolyuchin Bay.Behaviour
This wader is highly gregarious, and will form flocks with other calidrid waders, particularly dunlin. Despite its easterly breeding range, this species is regular on passage in western Europe, presumably because of southwesterly migration route.Breeding
The breeding grounds are occupied from June till late August. The male curlew sandpiper performs an aerial display during courtship. The nesting site is at the edge of a marsh or pool, or on dry patches of tundra. The average clutch size is 3.8 eggs which are laid at daily intervals. The eggs are incubated by the female and hatch after 19–20 days. The chicks are cared for by the female for 14–16 days.The reproductive success of this species appears to be dependent on the population of lemmings, East Siberian lemmings and the Arctic lemming. In poor lemming years, predatory species such as the Arctic fox will take Arctic-breeding waders instead.