Sharp-tailed Sandpiper

Identificazione

A small-medium wader, the portly sandpiper has a pot belly, flat back and somewhat drawn-out rear end. It has a mottled chestnut-brown upper body with sharp-looking feathers with a dark centre, a chestnut cap on its head and a brown stripe through each eye. Its bill is dark grey to black and straight, and its legs are olive- to yellow-coloured. The underparts are white or paler in colour, with the mottling similar to that on the breast and sides of the belly. The plumage is duller during wintering and more vivid during the breeding season. The juveniles are brighter in colour during wintering than adults, with sharper feathers and brighter chestnut-coloured crowns contrasting with the white mantle stripes and bright, buffy chests.<p>A similar-looking species is the pectoral sandpiper, within whose Asian range the sharp-tailed sandpiper breeds. It differs from that species in its breast pattern, stronger supercilium, and more chestnut-coloured crown. It has some similarities to the long-toed stint, but is much larger.

Tassonomia

The genus name calidris comes from the Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific acuminata is from Latin acuminatus, 'sharp, pointed'.<p>It had previously been suggested that the sharp-tailed sandpiper should perhaps be placed into the genus Philomachus – as P. acuminatus – which contains the ruff, however this proposed change has yet to receive widespread acceptance.

Nome scientifico

Calidris acuminata

Autorità

(Horsfield, 1821)

Ordine

Caradriformi

Famiglia

Scolopacidi

Genere

Calidris

Areale e habitat

In Siberia the breeding ground is mostly tundra made up of peat-hummock and lichen. On passage between breeding and wintering areas they favor the muddy edges of shallow freshwater or brackish wetlands with grass, emergent or inundated sedges, saltmarsh or other low vegetation. These include swamps, lakes, lagoons, and pools near coasts, waterholes, dams, saltpans and hypersaline salt lakes inland. In Alaska they seem to prefer coastal moist graminoid meadows and riverine intertidally exposed mudbanks. In Australia they are largely found around wetlands, preferring freshwater inland wetlands with grassy edges. Once the ephemeral terrestrial wetlands have dried out, they tend to be seen on coastal mudflats, salt marsh and brackish lagoons and less often on similar wet fields of short grass. Other areas they have been spotted in Australia include around sewage farms, flooded fields, mangroves, rocky shores and beaches.

Areale riproduttivo

PAL : low Arctic to subarctic tundra of ne Palearctic: Lena to Kolyma rivers (ne Siberia)

Areale non riproduttivo

AU : coastal and inland Wallacea, New Guinea, Australia, Melanesia, New Zealand and Fiji (sw Polynesia); prone to extreme vagrancy to North America and Europe

Migrazione

Migratori completi

Comportamento

Comportamento migratorio: Migratori completi.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione