Behaviour This species is an intra-African trans-equatorial migrant, making movements that are triggered by the rains (del Hoyo et al. 1992, Hancock et al. 1992). It breeds during in the rains when snails (its main prey items) are most readily available. It nests in colonies of various sizes, often with other species (del Hoyo et al. 1992, Hancock et al. 1992). Nesting may only occur in years when local food supplies are plentiful; however, it may not occur regularly at the same site (Hancock et al. 1992). The species feeds in loose groups that may contain up to 50 well-dispersed individuals; flocks of over 7,000 may also occur in some seasons (Brown et al. 1982, Hancock et al. 1992). It migrates in flocks and roosts communally in trees (Brown et al. 1982, del Hoyo et al. 1992).
Habitat The species inhabits freshwater wetlands with shallow waters and a large abundance of aquatic molluscs, including marshes, swamps, rice-fields, flood-plains, the backwaters and margins of lakes or rivers, ponds and streams (del Hoyo et al. 1992, Hancock et al. 1992). It may also frequent moist savanna or burnt grassland, as well as occasionally forest clearings, coastal mudflats and mangrove swamps (del Hoyo et al. 1992, Hancock et al. 1992).
Diet In many regions, the species may depend entirely upon molluscs such as aquatic snails (e.g. Pila spp. or Lanistes ovum) and freshwater mussels (Ampullaria spp.) (del Hoyo et al. 1992, Hancock et al. 1992). Other prey items taken include frogs, crabs, worms, fish and insects (e.g. locusts and beetles) (del Hoyo et al. 1992, Hancock et al. 1992).
Breeding site The nest is a small platform of sticks and vegetation positioned in trees and bushes over water (e.g. inundated in standing water on flood-plains), or alternatively in reedbeds (Brown et al. 1982, del Hoyo et al. 1992, Hancock et al. 1992). It nests colonially, often in mixed-species groups (Hancock et al. 1992).