White-rumped Sandpiper

White-rumped Sandpiper (Calidris fuscicollis) is a small, long-winged sandpiper recognised in flight by its white rump and on the ground by its streaked breast and fine bill. Body shape, bill structure, plumage pattern and voice provide the strongest field characters. Age, sex and season may alter its appearance, so identification should combine several features and careful direct field comparisons with similar species in the same habitat (Wikipedia, general species account).

It breeds in the Arctic, migrates to South America and feeds on small invertebrates picked or probed from mudflats, wetland edges and shallow water. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant or visitor (Wikipedia, general species account; Wildlife of Japan occurrence records).