| Sharp-tailed sandpiper | |
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Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Charadriiformes |
| Family: | Scolopacidae |
| Genus: | Calidris |
| Species: | C. acuminata |
| Binomial name | |
| Calidris acuminata (Horsfield, 1821) | |
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The sharp-tailed sandpiper (Calidris acuminata) is a small-medium migratory wader or shorebird, found mostly in Siberia during the summer breeding period (June to August) and Australia for wintering (September to March).
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'. [2]
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. [3]
A small-medium wader, the portly sandpiper has a pot belly, flat back and somewhat drawn-out rear end. [4] 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. [5] The plumage is duller during wintering and more vivid during the breeding season. [6] [7] 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. [5]
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.
Sharp-tailed sandpipers are strongly migratory, breeding solely in eastern Siberia from the Taymyr Peninsula to Chaunskaya Bay in Chukotka. They have a complex migration, with adults departing Siberia in July and juveniles in August to head south, where the majority of the population winters in Australasia. They take two main routes, with the majority of post-breeding adults flying south in flocks of less than 1000, east of Lake Baikal, to the Pacific coast of Russia and the Yellow Sea coasts of China and Korea. They mostly all fly directly to Micronesia and New Guinea in late August, departing here with the onset of the wet season to northwest Australia in mid-September. They start moving towards southeast Australia with numbers peaking in December to February. The other route heads east, taking most juveniles and a few adults into Alaska across the Bering Strait. Staying here from mid-August to late October to fatten up, it is presumed they then take a direct non-stop trans-Pacific flight of more than 10,000 km to reach Australia and New Zealand. Some will continue south along the Pacific coast of North America into Washington, less frequently to California, and possibly into Latin America, but only two recent records occur in Panama and Bolivia. [9] [5]
It occurs as a rare autumn migrant to North America, but in western Europe only as a very rare migrant with records in 11 different countries, mostly in the United Kingdom, between August and October. It has been recorded in the Middle East and Central Asia, six times in Kazakhstan, once in Yemen and Oman. Within the Indian Ocean they have been documented at Christmas Island four times, totalling 16 birds between October and December. There have been three recorded observations at Cocos Island in November and December; five records at the Chagos archipelago from September to December; and five records in Seychelles, one in July, two in September to February overwintering, and two on passage in November. They have been recently documented in Mozambique, recorded in southern Africa for the first time in 2018. [9]
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. [9] In Alaska they seem to prefer coastal moist graminoid meadows and riverine intertidally exposed mudbanks. [10] In Australia they are largely found around wetlands, preferring freshwater inland wetlands with grassy edges. [7] 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. [9] Other areas they have been spotted in Australia include around sewage farms, flooded fields, mangroves, rocky shores and beaches. [7]
Little is known about the specific behaviour of the sharp-tailed sandpiper, but generally its behaviour and structure are most similar to the pectoral sandpiper. [5]
Sharp-tailed sandpipers breed from to June to August in the short Siberian summer, making shallow, hollow, lined nests made of leaves and grass. The nests are hidden on the ground and hard to distinguish from surrounding the surrounding landscape. The clutch size is usually four eggs, with the females incubating and raising the chicks. [6] The breeding plumage is more vivid, with breast feathers greater in chestnut colour and their chevron-shaped markings becoming more defined. [7]
Sharp-tailed sandpipers forage on the edge of wetlands, intertidal mudflats, either on sand or bare wet mud and in shallow water. They will also forage among inundated vegetation of grass, sedges or saltmarsh. After rain they can be found in paddocks of short grass, well away from water. At low tides they can be found on the intertidal mudflats, before moving inland to freshwater wetlands at the high tide. Occasionally they forage on dry or wet mats of algae, among rotting seaweed or seagrass on beaches, edges of stony wetlands and exposed reefs. [4] Picking up food by sight or sometimes by probing, they mainly eat aquatic insects, molluscs, crustaceans, worms, occasionally seeds and other invertebrates. [7]
The species is currently listed as vulnerable globally by the IUCN in 2021, with an estimated number of 60,000 to 120,000 mature individuals and a decreasing population trend. [11] The major threats to the species are habitat loss, with the staging areas used in migration being reduced through reclamation of land for aquaculture or degraded from human activities. In Australia this occurs through clearing, inundation, draining or infilling of wetlands, and reduces the availability of foraging and roosting sites. This affects their ability to build up the energy to complete the return trip back to the breeding grounds in Siberia. Habitat degradation also occurs in the form of the loss of riparian vegetation, invasive species, water pollution, and hydrological regime changes from human-induced regulation. Sharp-tailed sandpipers are also subject to disturbance from humans, namely in encroaching residential and recreational activities, disturbing their breeding and foraging habits. They also experience increased direct mortality from hunting, vehicle collisions, aircraft strikes and predation by pest fauna, foxes and cats. [4]
The semipalmated sandpiper is a very small shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific pusilla is Latin for "very small".
The dunlin is a small wader, formerly sometimes separated with the other "stints" in the genus Erolia. The English name is a dialect form of "dunling", first recorded in 1531–1532. It derives from dun, "dull brown", with the suffix -ling, meaning a person or thing with the given quality.
The little stint is a very small wader. It breeds in arctic Europe and Asia, and is a long-distance migrant, wintering south to Africa and south Asia. It occasionally is a vagrant to North America and to Australia. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific minuta is Latin for "small.
The least sandpiper is the smallest shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-colored waterside birds. The specific minutilla is Medieval Latin for "very small".
The red knot or just knot is a medium-sized shorebird which breeds in tundra and the Arctic Cordillera in the far north of Canada, Europe, and Russia. It is a large member of the Calidris sandpipers, second only to the great knot. Six subspecies are recognised.
The western sandpiper is a small shorebird. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific mauri commemorates Italian botanist Ernesto Mauri (1791–1836).
The white-rumped sandpiper is a small shorebird that breeds in the northern tundra of Canada and Alaska. This bird can be difficult to distinguish from other similar tiny shorebirds; these are known collectively as "peeps" or "stints".
The bar-tailed godwit is a large and strongly migratory wader in the family Scolopacidae, which feeds on bristle-worms and shellfish on coastal mudflats and estuaries. It has distinctive red breeding plumage, long legs, and a long upturned bill. Bar-tailed godwits breed on Arctic coasts and tundra from Scandinavia to Alaska, and overwinter on coasts in temperate and tropical regions of Australia and New Zealand. The migration of the subspecies Limosa lapponica baueri across the Pacific Ocean from Alaska to New Zealand is the longest known non-stop flight of any bird, and also the longest journey without pausing to feed by any animal. The round-trip migration for this subspecies is over 29,000 km (18,020 mi).
The ruff is a medium-sized wading bird that breeds in marshes and wet meadows across northern Eurasia. This highly gregarious sandpiper is migratory and sometimes forms huge flocks in its winter grounds, which include southern and western Europe, Africa, southern Asia and Australia.
The red-necked stint is a small migratory wader. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific ruficollis is from Latin rufus, "red" and collum, "neck".
The curlew sandpiper is a small wader that breeds on the tundra of Arctic Siberia.
The broad-billed sandpiper is a small wading bird. The scientific name is from Latin. The specific name falcinella is from falx, falcis, "a sickle. Some research suggests that it should rather go into the genus Philomachus.
The long-toed stint is a small wader. The genus name is from Ancient Greek kalidris or skalidris, a term used by Aristotle for some grey-coloured waterside birds. The specific subminuta is from Latin sub, "near to" and minuta, "small" from its similarity to the little stint, Calidris minuta.
The great knot is a small wader. It is the largest species of the genus Calidris. They are a migratory bird which breeds in Siberia, Russia, and flies to southern Asia and Australia in the northern winter.
Calidris is a genus of Arctic-breeding, strongly migratory wading birds in the family Scolopacidae. These birds form huge mixed flocks on coasts and estuaries in winter. Migratory shorebirds are shown to have decline in reproductive traits because of temporal changes of their breeding seasons. They are the typical "sandpipers", small to medium-sized, long-winged and relatively short-billed.
The pectoral sandpiper is a small, migratory wader that breeds in North America and Asia, wintering in South America and Oceania. It eats small invertebrates. Its nest, a hole scraped in the ground and with a thick lining, is deep enough to protect its four eggs from the cool breezes of its breeding grounds. The pectoral sandpiper is 21 cm (8.3 in) long, with a wingspan of 46 cm (18 in).
The stilt sandpiper is a small shorebird. The scientific name is from Ancient Greek. The genus name kalidris or skalidris is a term used by Aristotle for some grey-coloured waterside birds. The specific himantopus means "strap foot" or "thong foot".
The buff-breasted sandpiper is a small shorebird. The species name subruficollis is from Latin subrufus, "reddish" and collis, "-necked/-throated". It is a calidrid sandpiper.
Cox's sandpiper is a hybrid between a male pectoral sandpiper and a female curlew sandpiper. First discovered in Australia in the 1950s, it was originally described as a species new to science and named after Australian ornithologist John B. Cox. However, it was later found to be a hybrid. Most if not all birds found to date are males, in accord with Haldane's rule.
The spoon-billed sandpiper is a small wader which breeds on the coasts of the Bering Sea and winters in Southeast Asia. This species is highly threatened, and it is said that since the 1970s the breeding population has decreased significantly. By 2000, the estimated breeding population of the species was 350–500.
