curvirostra

Curvirostra is a genus of medium‑sized wading birds that belong to the family Recurvirostridae. The genus comprises two extant species, Curvirostra lapponica, commonly known as the common avocet, and Curvirostra thoracica, the thick‑billed avocet. The two species are closely related, share many morphological features, and are sometimes referred to collectively as avocets. The name Curvirostra derives from the Latin words curvatus, meaning curved, and rostrum, meaning beak, a reference to their distinctive up‑curled bills.

Adult avocets are slender, with long, thin legs and a long, straight or slightly up‑curved bill that points upward during foraging. They typically measure between 68 and 76 centimetres from the tip of the bill to the tip of the tail, and weigh from 0.8 to 1.2 kilograms. They possess a pale brown plumage on the upperparts, gray or white on the underparts, and a narrow white stripe running down the side of the neck. Their legs are long, pink or reddish in adults, and they have a long, narrow tail. Juveniles and subadults are generally duller and exhibit less contrast between the upper and lower plumage.

These birds inhabit shallow wetlands, marshes, estuarine flats, and some tidal creeks. The common avocet breeds throughout the northern hemisphere, largely in tundra and Arctic coastal regions, whereas the thick‑billed avocet breeds in the high Andes of South America. Both species exhibit strong migratory behavior, with the common avocet wintering in coastal and shallow inland waters from Europe to North Africa and West Africa, while the thick‑billed avocet has more restricted wintering ranges and is considered less mobile.

Avocets feed by sweeping their long, up‑curving bill through shallow water, picking up small invertebrates such as insects, crustaceans, and molluscs. Their foraging technique involves a wobbly, sweeping motion that sweeps the bill from side to side, enabling them to capture prey hidden beneath the water surface. They also consume small fish, amphibians, and occasionally plant matter.

The conservation status of Curvirostra species varies. The common avocet is listed by the IUCN as Least Concern. The thick‑billed avocet also does not meet criteria for a more severe threat category, but localized population declines have been reported due to habitat loss and degradation. Conservation measures for both species involve monitoring of migratory routes, protection and restoration of wetland habitats, and management of water politics in breeding and wintering regions.