UK passage: 740 birds
Family: Sandpipers & allies
In breeding plumage, curlew sandpipers have dark brown upperparts with white, black, and chestnut fringes giving it a mottled appearance and grey wing coverts. The breast is a deep rufous colour while the vent, undertail coverts, and underwings are white.
The head and neck are rufouse with dark streaks on the crown. The long bill, which curves slightly downwards is black, the eyes are dark brown, and the legs and feet are black.
Males and females are similar but the female has a slightly longer bill and may be paler with white bars on the underparts.
Out of breeding plumage, curlew sandpipers have grey upperparts with a white rump and uppertail coverts. The underparts are white with a grey tinge on the breast, and the tail is grey.
On the head there is a broad, white supercilium, and the lores and the eyeline are dark.
Juvenile curlew sandpipers resemble adults in non-breeding plumage but they have browner upperparts with white edges to the feathers, and the breast is pale buff with faint streaks.
Curlew sandpipers breed in June and July. They nest close to marshes, pools, and wet grassy areas. The nest which is built by the female is a shallow scrape on the ground lined with leaves, moss, and lichens.
Curlew sandpipers lay 3-4 cream-coloured, yellow, or olive eggs with cryptic dark markings which are incubated by the female alone for 19-21 days. The chicks leave the nest soon after hatching and they are led by the female to more grassy areas. They can feed themselves but are cared for by the female for some time more. They fledge 2 weeks after hatching.
Curlew sandpipers eat crustaceans, molluscs, marine worms, and insects. They may also supplement their diet with seeds.
Curlew sandpipers can be seen on passage in April and May and again from July to October. Look out for them along the coats of eastern and southern England on saltmarshes, muddy pools, and coastal lagoons.
Curlew sandpipers occasionally hybridize with the sharp-tailed sandpiper and the pectoral sandpiper producing the Cooper’s sandpiper (“Calidris” × cooperi) and Cox’s sandpiper (“Calidris” × paramelanotos), respectively.