White-rumped Sandpiper (Calidris fuscicollis)
4th+5th+6th August 2021
[order] Charadriiformes | [family] Scolopacidae | [latin] Calidris fuscicollis | [UK] White-Rumped Sandpiper | [FR] Bécasseau à croupion blanc | [DE] Weißbürzel-Strandläufer | [ES] Correlimos Culiblanco | [IT] Piro-piro dorsobianco | [NL] Bonapartes-strandloper
spanwidth min.: 41 cm
spanwidth max.: 43 cm
size min.: 15 cm
size max.: 16 cm
incubation min.: 21 days
incubation max.: 22 days
fledging min.: 16 days
fledging max.: 17 days
eggs min.: 3
eggs max.: 4
White uppertail-coverts contrast with dark rump and tail; yellow base to lower mandible; crown, cheeks, mantle and scapulars centred dark brown and edged rufous pink and grey; wing-coverts paler; sides of neck, breast and flanks spotted and streaked brown; at rest, wings project beyond tail tip. Male has inflatable throat; female averages slightly larger, with smaller white throat. Non-breeding adult has head and upperpart8 plain ashy brown with faint streaks and paler fringes; breast pale ashy brown with faint dark streaks. Juvenile like breeding adult, but upperparts more brightly colored, and with more white tips; breast streaked and washed buff-grey.
Breeds in low areas on marshy, hummocky tundra, well vegetated with mosses, grasses, sedges or shrubs. On migration in N South America, occurs on sea beaches, riverbanks, open fields and marshes. On wintering grounds, on intertidal mudflats, salt-marshes, flood fields, marshes, ponds and lagoons.
Breeds on mainland and islands of Arctic Canada from northern Mackenzie east to south Baffin Island, irregular in northern Alaska. Accidental in Spitsbergen, Iceland (almost annual), Britain (annual), Ireland (near annual), France, Belgium, Netherlands, Germany, Denmark, Norway, Sweden, Finland, Austria, Switzerland, Spain, Balearic Islands, Russia (Franz Josef Land), Azores, Madeira, Canary Islands. One of most numerous Nearctic vagrants.
Invertebrates, including adult and larval insects, such as grasshoppers, beetles and cranetlies, also spiders, small molluscs, crustaceans, leeches, polychaete worms and earthworms; some seeds. On breeding grounds, probes in moss and wet vegetation; during non-breeding season probes in muddy substrates at edge of water and picks prey from surface. May defend feeding territories on wintering grounds.
Egg laying early to mid June. Polygynous and solitary, territory vigorously defended by male during egg-laying. Nests usually widely spaced, but sometimes as close as 12 m. Male extends highly inflatable throat while performing aerial display. Nests are built near ponds, lakes or streams, well hidden, shallow scrape with lining of willow leaves and bits of moss and lichens. 4 eggs are laid females single-brooded, incubation period about 22 days. Male deserts female soon after egg-laying. Chicks are mottled grey-brown or tawny and black above with white spots.
Migratory. Migrates in few, non-stop jumps of up to 4,000 km; flies from NE North America over W Atlantic directly to N South America, whence continues with short hops down coast, then moving inland at mouth of R Amazon, reaching wintering grounds 1 month later; shows some degree of site fidelity. During N migration flies across Central America, Caribbean and inland North America, staging Great Planes; little information on other staging areas. Departs from winter quarter Mar to mid-Apr, arriving N South America late Apr to mid-May, and on breeding grounds early Jun. Leaves breeding grounds up to early Aug; arrives at Canadian coast Aug to early Sept, n South America late Aug, and S Brazil and Argentina mid-Nov to Dec.