The white-rumped sandpiper (''Calidris fuscicollis'') is a small
shorebird
245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots
Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...
that breeds in the northern tundra of
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
and
Alaska
Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U.S. ...
. This bird can be difficult to distinguish from other similar tiny shorebirds; these are known collectively as "peeps" or "
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. They are scolopacid waders much similar in ecomorphology to the ...
s".
These birds are not often spotted. In the summer, they are rarely seen because they are in such an obscure breeding location. Similarly, in the winter they are rarely seen because they travel too far south for many birdwatchers. Therefore, the majority of sightings occur during the spring or fall in temperate regions and are generally in small numbers around water.
[
]
Taxonomy
The white-rumped sandpiper is placed in the order Charadriiformes
Charadriiformes (, from ''Charadrius'', the type genus of family Charadriidae) is a diverse order of small to medium-large birds. It includes about 390 species and has members in all parts of the world. Most charadriiform birds live near water an ...
along with gulls
Gulls, or colloquially seagulls, are seabirds of the family Laridae in the suborder Lari (bird), Lari. They are most closely related to the terns and Skimmer (bird), skimmers and only distantly related to auks, and even more distantly to waders ...
, alcids
An auk or alcid is a bird of the family Alcidae in the order Charadriiformes. The alcid family includes the murres, guillemots, auklets, puffins, and murrelets. The word "auk" is derived from Icelandic ''álka'', from Old Norse ''alka'' (a ...
, plovers
Plovers ( , ) are a widely distributed group of wading birds belonging to the subfamily Charadriinae.
Description
There are about 66 species in the subfamily, most of them called "plover" or "dotterel". The closely related lapwing subfa ...
and oystercatchers
The oystercatchers are a group of waders forming the family Haematopodidae, which has a single genus, ''Haematopus''. They are found on coasts worldwide apart from the polar regions and some tropical regions of Africa and South East Asia. The e ...
. Its family, Scolopacidae
Sandpipers are a large family, Scolopacidae, of waders. They include many species called sandpipers, as well as those called by names such as curlew and snipe. The majority of these species eat small invertebrates picked out of the mud or soil. ...
, encompasses all sandpipers, and as a stint it is classified in the genus Calidris
''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. They are the typical "sandpipers", small to medium-sized, long-winged ...
.[ It is classified as monotypic species, meaning that no population differentiation or subspecies have been described.][
The genus name is from ]Ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...
''kalidris'' or ''skalidris'', a term used by Aristotle
Aristotle (; grc-gre, Ἀριστοτέλης ''Aristotélēs'', ; 384–322 BC) was a Greek philosopher and polymath during the Classical period in Ancient Greece. Taught by Plato, he was the founder of the Peripatetic school of ph ...
for some grey-coloured waterside birds. The specific ''fuscicollis'' is from Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
''fuscus'', "dusky" and New Latin
New Latin (also called Neo-Latin or Modern Latin) is the revival of Literary Latin used in original, scholarly, and scientific works since about 1500. Modern scholarly and technical nomenclature, such as in zoological and botanical taxonomy ...
''collis'', "necked ".
Description
The white-rumped sandpiper is a relatively small bird measuring only .[ The top of its body is a dull grey-brown color and it has a white eye stripe. Its beak is of medium length, thin and dark, and its legs are very dark. This bird is often mistaken with many similar-looking sandpipers that live in its range or along its migration path.][
The plumage is much less distinct during the winter; however, during all seasons males and females remain similar in their appearance.][ In adult alternate plumage, the crown and face have a brownish tinge. The supercilium is pale, there are black feathers on the back and there are grey edges on the ]wing coverts
A covert feather or tectrix on a bird is one of a set of feathers, called coverts (or ''tectrices''), which, as the name implies, cover other feathers. The coverts help to smooth airflow over the wings and tail. Ear coverts
The ear coverts are s ...
. The breast and flanks are streaked and the underparts are white. In adult basic plumage, the upperparts are a dark grey and at the centers there are black feathers. The underparts are white but the breast is dark grey. The supercilium is white, while the crown and eyeline are darker. The juvenile plumage features black-based feathers on the back and wing coverts. These have brown edges towards the scapulars and whiter edges towards the wing coverts. The breast is finely streaked and there is a white "V" on its back. The underparts and supercilium are white, the crown is brownish in color, and the face is pale[
]
Identification
The two primary features used to identify this bird in the field are its long wings and its white rump. The white patch on the rump can be seen while the bird is in flight. Its long wings extend beyond the tail by about a quarter inch.[ Baird's sandpiper also shows this trait but can be distinguished by the lack of a white rump. There is also a thin white stripe on the wing][ and a row of marks on the flanks below the wings.][
]
Habitat and distribution
The white-rumped sandpiper inhabits relatively vegetated patches of the tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...
.[ More specifically, they live in the marshy, heavily vegetated, hummocky ]arctic tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mou ...
of Alaska and Canada during the breeding season.[ They can be found in various types of wetlands while migrating. During the winter months they inhabit a variety of freshwater and saltwater habitats such as ]lagoons
A lagoon is a shallow body of water separated from a larger body of water by a narrow landform, such as reefs, barrier islands, barrier peninsulas, or isthmuses. Lagoons are commonly divided into ''coastal lagoons'' (or ''barrier lagoons'') an ...
, estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...
and marshes
A marsh is a wetland that is dominated by herbaceous rather than woody plant species.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p Marshes can often be found at ...
. In general, they tend to avoid sandy beaches and fast moving water.[
]
Migration
They are a long distance migrant, wintering in southern South America and the Caribbean. They are considered one of the most extreme long distance migrants in the world,[ traversing the entire continent of North America in the span of one month.][
The white-rumped sandpiper is a nearctic migrant. After breeding in northern Canada and Alaska, it flies over the Atlantic Ocean to spend the majority of its non-breeding period in South America, particularly along the Patagonian coast in both ]Chile
Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...
and Argentina
Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
. It also frequently visits Fracasso Beach, Argentina. Many shorebirds concentrate in this area due to the abundance of intertidal
The intertidal zone, also known as the foreshore, is the area above water level at low tide and underwater at high tide (in other words, the area within the tidal range). This area can include several types of habitats with various species ...
invertebrate
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordate ...
s, especially clams.[ The white-rumped sandpiper has also been spotted in ]Venezuela
Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...
, Suriname, Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
and Paraguay
Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...
during its migration. They are rare but regular vagrants to western Europe and a rare vagrant to Australia.
The birds migrate with both nonstop and short-distance multiple-stop flights. During their migration from north to south, they fly over the Atlantic Ocean, gradually moving along the northeastern coast of South America before heading inland towards the islands. This travel generally takes about one month. On their migration from south to north, the white-rumped sandpiper follows a similar path, but does it much more quickly. This migration is done in a fast series of long flights without stopping. One nonstop flight can be as long as .[
Weather patterns play a crucial role in determining the migration route. Birds like to travel so that the temperature, pressure and humidity work with the tailwinds. Strong winds can blow birds off of their regular migration route. For example, the effects of a large storm lead to a higher presence of the white-rumped sandpiper on the ]King George Islands
The King George Islands (''Îles du Roi Georges'') is a subgroup of the Tuamotus Archipelago group in French Polynesia.
The King George Islands include four atolls and one island:
* Ahe
* Manihi
* Takapoto
* Takaroa
* Tikei Island
Tikei ...
.[
]
Effects of climate change
The warming of the climate has led to changes in the number of individuals and the length of their stay in the South Shetland Islands
The South Shetland Islands are a group of Antarctic islands with a total area of . They lie about north of the Antarctic Peninsula, and between southwest of the nearest point of the South Orkney Islands. By the Antarctic Treaty of 1 ...
.[ White-rumped sandpipers are now observed more frequently in this area as a result of both long and short term climate variations. The higher air temperatures, which occur as a result of the northern winds, bring warm, moist air which creates more open habitats and better food resources that allow these birds to persist and survive. Migration routes, as well as both winter and summer foraging grounds, may also be altered.][
]
Behavior
Vocalizations
One of the white-rumped sandpiper vocalizations consists of a repeating "pip, pip, pip …"[ Their call has a distinctive metallic "tzeep" note which makes them easily identifiable among a flock of shorebirds. It resembles the sound of two pebbles scraping against one another.][
]
Diet
Their diet consists primarily of small invertebrates
Invertebrates are a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chordat ...
including: molluscs
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estim ...
, crustaceans
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...
, polychaete
Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made ...
s, annelids
The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecolog ...
and both adult and larval insects
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of j ...
. They are mainly reported to eat aquatic invertebrates. Although it was previously thought they only consumed invertebrates, it has been shown that seed
A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s and moss also make up a portion of the white-rumped sandpiper diet. This discovery lead to the idea that they might be opportunistic feeders depending on time, season and habitat. Stones and algae have also been found in their stomachs but these are most likely ingested by accident. The stones are of the same general shape and size as the seeds so it could be a case of mistaken identity. Algae could also be accidentally ingested through aquatic feeding.[
While on mudflats, the white-rumped sandpiper forages by probing in shallow waters and in mud but can also pick up some items from the surface. When they are in the tundra, they must probe deeply in the moss and other vegetation.][
]
Nesting
The females build the nest which is a cup-shaped depression in the ground. The nest is lined with pieces of lichen, leaves and moss which can occur naturally or can be added by the female. The nests are generally well hidden in a clump of moss or grass. Males defend the breeding territory by gliding and fluttering above it while making oinking and rattling sounds. When on the ground, the male stretches its wing out to the side and raises its tail into the air to display the white patch on its rump. He then walks and runs while repeating a call.[
]
Reproduction
As with most shorebirds, the courtship behavior of the white-rumped sandpiper involves an aerial component. During courtship the male and the female fly upward side by side at an angle. At about above the ground they stop about apart and hover with shallow, rapidly vibrating wingbeats. The male remains above the female and repeatedly releases a series of "poing-zee" notes. They hover between 5 and 10 seconds before descending to the ground slowly and silently and land about apart. During their downward glide their wings are held together in a "V" position above their backs. A few minutes later they initiate a second paired flight identical to the first one. However, once they have landed on the ground the male begins to chase the female. The chase ends when the male does a wing raising display, which is common in many sandpiper species.[
]
The females are small and nest in the high arctic, which means they are more likely under a higher cold stress than birds nesting in temperate
In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout ...
areas. Consequently, the females spend an average of 82.5% of their time incubating their eggs.[ In total, the females incubate the eggs for about 22 days. She generally lays 4 olive to green eggs; laying 3 eggs is rare. The eggs can sometimes be blotched with brown, olive-brown or grey spots.][
Only the females incubate the eggs.][ Once the female has laid the eggs, the male stops displaying and leaves the breeding grounds.][ This is unlike other members of the calidris genus where incubation is shared between males and females; therefore, the trait of male incubation has been independently lost in this species. There are only three documented species who have been known to share this behaviour. This development seems bizarre since experiments have shown that a decrease in the amount of male care is linked to a decrease in male fitness by lowering the number of male descendants that survive. One explanation for this evolution is that a decrease in male care allows the males to explore other breeding options. This hypothesis ties in with the fact that the white-rumped sandpiper is polygynous; males will mate with several females but females will only mate with one male.][
Hybrids between this species and the ]dunlin
The dunlin (''Calidris alpina'') 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 ...
are occasionally found in northeastern North America.[ The white-rumped sandpiper is also suspected to hybridize with the buff-breasted sandpiper.
]
Early development
The young are covered in down feathers
The down of birds is a layer of fine feathers found under the tougher exterior feathers. Very young birds are clad only in down. Powder down is a specialized type of down found only in a few groups of birds. Down is a fine thermal insulator an ...
and leave the nest about a day after hatching. The female will tend to them by brooding them and keeping them warm, but they must find all their own food. Their first flight is at the age of about 16–17 days and soon after that they become independent.[
]
References
External links
North American Peeps: A Different Look at an Old Problem (identification article covering this species and other small calidrids)
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surfbirds.com
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{{Taxonbar, from=Q599749
Birds of the Arctic
white-rumped sandpiper
white-rumped sandpiper
white-rumped sandpiper
Native birds of Alaska
Birds of Canada
Birds of the Dominican Republic
Birds of the Caribbean
Birds of South America
white-rumped sandpiper
white-rumped sandpiper