Curlew Sandpiper
Encyclopedia
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 Australasia
. It is a vagrant
to North America
.
at 19.5–21 cm in length, but differ from Dunlin in having a longer down-curved bill
, longer neck and legs and a white rump. 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.
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 the southwesterly migration
route.
It forage
s in soft mud on marsh
es and the coast, mainly picking up food by sight. It mostly eats insect
s and other small invertebrate
s.
The numbers of this species (and of Little Stint
) depend on the population of lemming
s. In poor lemming years, predatory species such as skua
s and Snowy Owl
s will take Arctic-breeding waders instead.
This species occasionally hybridizes with the Sharp-tailed Sandpiper
and the Pectoral Sandpiper
, producing the presumed "species" called "Cooper's Sandpiper" ("Calidris" × cooperi) and "Cox's Sandpiper
" ("Calidris" × paramelanotos), respectively.
of the genus Erolia but the DNA sequence
data is currently insufficient to resolve its relationships (Thomas et al., 2004). This matter is of taxonomic relevance since, as the Curlew Sandpiper is the type species, a close relationship with the small "stint
" sandpipers would preclude the use of Erolia for the present species.
The Curlew Sandpiper is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA
) applies.
Wader
Waders, called shorebirds in North America , are members of the order Charadriiformes, excluding the more marine web-footed seabird groups. The latter are the skuas , gulls , terns , skimmers , and auks...
that breeds on the tundra
Tundra
In physical geography, tundra is a biome where the tree growth is hindered by low temperatures and short growing seasons. The term tundra comes through Russian тундра from the Kildin Sami word tūndâr "uplands," "treeless mountain tract." There are three types of tundra: Arctic tundra, alpine...
of Arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
. It is strongly migratory
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
, wintering mainly in Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
, but also in south and southeast Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...
and in Australasia
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
. It is a vagrant
Vagrancy (biology)
Vagrancy is a phenomenon in biology whereby individual animals appear well outside their normal range; individual animals which exhibit vagrancy are known as vagrants. The term accidental is sometimes also used...
to North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
.
Description
These birds are small waders, only slightly larger than DunlinDunlin
The Dunlin, Calidris alpina, is a small wader, sometimes separated with the other "stints" in Erolia. It is a circumpolar breeder in Arctic or subarctic regions. Birds that breed in northern Europe and Asia are long-distance migrants, wintering south to Africa, southeast Asia and the Middle East...
at 19.5–21 cm in length, but differ from Dunlin in having a longer down-curved bill
Beak
The beak, bill or rostrum is an external anatomical structure of birds which is used for eating and for grooming, manipulating objects, killing prey, fighting, probing for food, courtship and feeding young...
, longer neck and legs and a white rump. 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
Supercilium
The supercilium is a plumage feature found on the heads of some bird species. It is a stripe which runs from the base of the bird's beak above its eye, finishing somewhere towards the rear of the bird's head. Also known as an "eyebrow", it is distinct from the eyestripe, which is a line which runs...
. Juveniles have a grey and brown back, a white belly and a peach-coloured breast.
Behaviour
The male Curlew Sandpiper performs an aerial display during courtship. The clutch of 3–4 eggs are laid in ground scrape in the tundra.This wader is highly gregarious, and will form flocks with other calidrid waders, particularly Dunlin
Dunlin
The Dunlin, Calidris alpina, is a small wader, sometimes separated with the other "stints" in Erolia. It is a circumpolar breeder in Arctic or subarctic regions. Birds that breed in northern Europe and Asia are long-distance migrants, wintering south to Africa, southeast Asia and the Middle East...
. Despite its easterly breeding range, this species is regular on passage in western Europe, presumably because of the southwesterly migration
Bird migration
Bird migration is the regular seasonal journey undertaken by many species of birds. Bird movements include those made in response to changes in food availability, habitat or weather. Sometimes, journeys are not termed "true migration" because they are irregular or in only one direction...
route.
It forage
Forage
Forage is plant material eaten by grazing livestock.Historically the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially...
s in soft mud on marsh
Marsh
In geography, a marsh, or morass, is a type of wetland that is subject to frequent or continuous flood. Typically the water is shallow and features grasses, rushes, reeds, typhas, sedges, other herbaceous plants, and moss....
es and the coast, mainly picking up food by sight. It mostly eats insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s and other small invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
s.
The numbers of this species (and of Little Stint
Little Stint
The Little Stint, Calidris minuta , 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...
) depend on the population of lemming
Lemming
Lemmings are small rodents, usually found in or near the Arctic, in tundra biomes. They are subniveal animals, and together with voles and muskrats, they make up the subfamily Arvicolinae , which forms part of the largest mammal radiation by far, the superfamily Muroidea, which also includes rats,...
s. In poor lemming years, predatory species such as skua
Skua
The skuas are a group of seabirds with about seven species forming the family Stercorariidae and the genus Stercorarius. The three smaller skuas are called jaegers in North America....
s and Snowy Owl
Snowy Owl
The Snowy Owl is a large owl of the typical owl family Strigidae. The Snowy Owl was first classified in 1758 by Carolus Linnaeus, the Swedish naturalist who developed binomial nomenclature to classify and organize plants and animals. The bird is also known in North America as the Arctic Owl, Great...
s will take Arctic-breeding waders instead.
This species occasionally hybridizes with the Sharp-tailed Sandpiper
Sharp-tailed Sandpiper
The Sharp-tailed Sandpiper, Calidris acuminata is a small wader.- Taxonomy :More recently, a review of new data has indicated that this bird should perhaps better be placed into the genus Philomachus- as P...
and the Pectoral Sandpiper
Pectoral Sandpiper
The Pectoral Sandpiper, Calidris melanotos, is a small wader. It is sometimes separated with the "stint" sandpipers in Erolia. This may or may not represent a good monophyletic group, depending on the placement of the phylogenetically enigmatic Curlew Sandpiper , the type species of Erolia...
, producing the presumed "species" called "Cooper's Sandpiper" ("Calidris" × cooperi) and "Cox's Sandpiper
Cox's Sandpiper
Cox's Sandpiper is the name given to shorebirds which are hybrids between male Pectoral and female Curlew Sandpipers. It was discovered in Australia in the 1950s, and named after Australian ornithologist John B. Cox...
" ("Calidris" × paramelanotos), respectively.
Taxonomy
This is a fairly unusual species, and has been proposed as type speciesType species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
of the genus Erolia but the DNA sequence
DNA sequence
The sequence or primary structure of a nucleic acid is the composition of atoms that make up the nucleic acid and the chemical bonds that bond those atoms. Because nucleic acids, such as DNA and RNA, are unbranched polymers, this specification is equivalent to specifying the sequence of...
data is currently insufficient to resolve its relationships (Thomas et al., 2004). This matter is of taxonomic relevance since, as the Curlew Sandpiper is the type species, a close relationship with the small "stint
Stint
A stint is one of several very small waders in the paraphyletic "Calidris" assemblage - often separated in Erolia -, which in North America are known as peeps...
" sandpipers would preclude the use of Erolia for the present species.
The Curlew Sandpiper is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA
AEWA
The Agreement on the Conservation of African-Eurasian Migratory Waterbirds is the largest of its kind developed so far under the Bonn Convention. It was concluded on 16 June 1995 at The Hague, the Netherlands and entered into force on 1 November 1999 after the required number of at least fourteen...
) applies.