The Crab Plover (Dromas ardeola) is a bird related to the waders, but sufficiently distinctive to merit its own family Dromadidae. Its relationship within the Charadriiformes is unclear (del Hoyo et al), some have considered it to be closely related to the thick-knees, or the pratincoles, while others have considered it closer to the auks and gulls. It is the only member of the genus Dromas.

Description

This bird resembles a plover, but has very long grey legs and a strong heavy black bill similar to a tern. Its black-and-white plumage and long-necked upright posture make it look like a cross between a pied avocet and a giraffe. Its bill is unique among waders, and specialised for eating crabs. It has partially webbed toes. The plumage is white except for black on its back and in the primary feathers of the wings. They are noisy birds, calling frequently on their breeding sites and in their wintering grounds.

The Crab Plover is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies.

Range

It is resident on the coasts and islands of the Indian Ocean, where it feeds on crabs and other small animals. They are gregarious and will feed in large groups, at night and during dawn and dusk as well as during the day; this crepuscular and nocturnal behaviour is more common during the breeding season. They breed around the Arabian Sea,Persian Gulf, Red Sea and Somalia in the months of April to July then disperse across the Indian Ocean in August as far as the Andaman Islands and Sri Lanka in the east and Tanzania and Madagascar.

Habits

The Crab Plover is unusual for waders in that it nests in burrows in sandy banks. It is a colonial breeder, nesting in colonies as large 1500 pairs. It lays one white egg, occasionally two, which are large for its body size. The nest burrow temperature is optimal due to solar radiation and the parents are able to leave the nest unattended for as long as 58 hours. The chicks are also unique for waders in being unable to walk and remain in the nest for several days after hatching, having food brought to them. Even once they fledge they have a long period of parental care afterwards.

Notes

1. ^ BirdLife International (2004). Dromas ardeola. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006.
2. ^ De Marchi, G., Chiozzi, G., Fasola, M. 2008 Solar incubation cuts down parental care in a burrow nesting tropical shorebird, the crab plover Dromas ardeola. Journal of Avian Biology 39 (5):484-486