Pectoral Sandpiper

Pectoral Sandpiper
Adult in breeding plumage
Adult non-breeding
Conservation status
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Subclass: Neornithes
Infraclass: Neognathae
Superorder: Neoaves
Order: Charadriiformes
Suborder: Scolopaci
Family: Scolopacidae
Genus: Calidris (disputed)
Species: C. melanotos
Binomial name
Calidris melanotos
Vieillot, 1819
Synonyms

Actodromas maculata
Erolia melanotos

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 ("C." ferruginea), the type species of Erolia. In any case, the genus name Ereunetes – formerly used for the Western Sandpiper ("C." mauri) and Semipalmated Sandpiper ("C." pusilla), which are also members of the stint clade – was established before Erolia.

"Cox's Sandpiper" ("Calidris" × paramelanotos) is a stereotyped hybrid between this species and the Curlew Sandpiper. This does not prove a particularly close relationship between these two species, as far more distantly related waders have successfully hybridized. In any case, among the stint clade the Red-necked Stint ("C." ruficollis) and the Long-toed Stint ("C." subminuta) are particularly close relatives of the Pectoral Sandpiper.[1]

Description

This bird looks similar to the widely sympatric Sharp-tailed Sandpiper ("C." acuminata), which is not a member of the stint clade however. The Pectoral Sandpiper is a largish calidrid (and hence not traditionally included with the smallish stints), with a grey-brown back, brownest in the summer male, and greyest in winter. The Pectoral Sandpiper has a grey breast, sharply demarcated at its lower edge, which gives this species its English name; this clear dividing line is particularly conspicuous if the birds are turned towards the observer. The legs are yellowish, and the bill is olive with a darker tip.

The juveniles are more brightly patterned above with rufous colouration and white mantle stripes.

This species differs from the Sharp-tailed Sandpiper in its breast pattern, weaker supercilium and greyer crown.

Distribution and ecology

It is a very long-distance migrant breeding in the boggy tundra of northeast Asia and North America. The American and most of the Asian birds winter in South America, but some Asian breeders winter in southern and Australia and New Zealand. On migration and in winter, the Pectoral Sandpiper is typically found in freshwater habitats.

This species also occurs as a regular migrant to western Europe, and is seen most years in Ireland or Great Britain[2]. While the Pectoral Sandpiper has not been recorded as breeding species in Europe, vagrant individuals were found in Scotland in suitable breeding habitat during summer.[3] Many of the birds occurring in Western Europe may be on a regular migration from Asian breeding grounds to winter in Southern Africa.[4] September 2003 saw a record influx to those two countries, with 40 found in Ireland and 150 in Great Britain. On the US Pacific coast, such stagings of migrant flocks appear to be rarer.[5] Vagrant individuals are sometimes seen elsewhere off the usual migration routes, e.g. on the Marianas, the Marshall Islands and Palau in Micronesia; they are somewhat more frequently encountered on the Hawaiian Islands[6].

The Pectoral Sandpiper's migration might be affected by global warming, as is suspected for many Arctic-breeding birds: 100 years ago, migrating Pectoral Sandpipers were observed to pass through northern Ohio in early-mid May and again in late August; today, the bulk of the northward migration takes place in April already, and most birds do not return until mid-September.[7]

These birds forage on grasslands and mudflats, picking up food by sight, sometimes by probing. They mainly eat arthropods and other invertebrates. The male has a courtship display which involves puffing up his breast, which has a fat sac in the breeding season to enhance his performance.

The Pectoral Sandpiper builds a steep-sided scrape nest with a considerable volume of lining material. The nest is deep enough that the eggs sit about 3 cm (1.2 in) below ground level, which helps to minimize heat loss from the cool breezes which occur at the latitudes where the species nests.[8] The female lays four eggs.

Footnotes

  1. ^ Thomas et al. (2004)
  2. ^ Harrison, Graham; Janet Harrison (2005). The New Birds of the West Midlands. West Midland Bird Club. ISBN 0950788120. http://www.westmidlandbirdclub.com/NBotWM. 
  3. ^ Vittery (1997)
  4. ^ Lees & Gilroy (2004)
  5. ^ For example the species was described as "unusual" in San Mateo County, California in the late 19th century, despite nearby San Francisco Bay offering excellent stopover habitat (Littlejohn 1916).
  6. ^ Wiles et al. (2004), VanderWerf (2006), VanderWerf et al. (2006)
  7. ^ Henninger (1906), OOS (2004)
  8. ^ Reid, J. M.; Cresswell, W; Holt, S; Mellanby, R. J.; Whitfield, D. P. & G. D. Ruxton (2002). "Nest scrape design and clutch heat loss in Pectoral Sandpiper (Calidris melanotos)". Functional Ecology 16: 305–312. doi:10.1046/j.1365-2435.2002.00632.x. 

References

External links