The Slender-billed Curlew, Numenius tenuirostris, is a wader in the large family Scolopacidae. It is the one of the rarest of the curlews, with a small and probably still declining population. It breeds in the taiga of Siberia, laying four eggs.
This is a migratory species, formerly wintering around the Mediterranean. The extent of its decline is reflected in the absence of wintering birds in the previously regular Moroccan site, although some birds have wintered in Italy recently. Remarkably, there is also a single recent record of a juvenile in Great Britain. This curlew is highly gregarious outside the breeding season, associating with related species .
This is a large wader, about Whimbrel size, but more resembles Eurasian Curlew. It is mainly greyish brown, with a white back. It is whiter on the breast, tail and underwing than the larger species, and the bill is shorter and differently curved. The flank spots are also a different shape. The calls are shorter and sharper than those of Eurasian Curlew.
This species feeds by probing soft mud for small invertebrates, but will also pick other small items off the surface if the opportunity arises.