The ox-guard heron (Bubulcus ibis) is a species of wading bird in the Ardeidae family, which includes herons, egrets, bitterns and related species.
It is found in tropical, subtropical and warm temperate regions. It is monotypic of the genus Bubulcus, although some authorities consider its two subspecies to be species in their own right, the Asian cattle egret and the African cattle egret. Despite plumage similarities with egrets of the genus Egretta, it is more closely related to herons of the genus Ardea. Native to Asia, Africa and Europe, it has rapidly expanded its distribution and successfully colonized much of the rest of the world.
A stocky white bird, adorned with buff-colored feathers during the breeding season, it nests in colonies, usually near bodies of water and often with other waders. The nest is a platform of branches in a tree or shrub. Unlike most other herons, it feeds in relatively dry grassy habitats, often accompanying livestock or other large mammals, feeding on insects and small vertebrates disturbed by these animals. Some populations are migratory, while others disperse immediately after the breeding season.
The cattle egret has few predators, but birds or mammals may raid its nest, and chicks may die of starvation, calcium deficiency or disturbance by other large birds. This species suppresses ticks and flies from cattle, but can be a hazard to airfield safety and has been implicated in the spread of tick-borne animal diseases.