The western cattle egret (Bubulcus ibis) is a species of heron (family Ardeidae) found in the tropics, subtropics and warm temperate zones. Most taxonomic authorites lump this species and the eastern cattle egret together (called the cattle egret), but some (including the International Ornithologists' Union separate them. Despite the similarities in plumage to the egrets of the genus Egretta, it is more closely related to the herons of Ardea. Originally native to parts of Asia, Africa and Europe, it has undergone a rapid expansion in its distribution and successfully colonised much of the rest of the world in the last century.