Hornbills (order: Bucerotiformes) are a group of distinctive and charismatic birds found only in Tropical Asia and sub-saharan Africa. There are two families (bucorvidae and bucerotidae), 15 genera, 57 species and 75 subspecies; 32 species are in Asia and 25 species in Africa. They are mostly large in size and have long bills surmounted in many species by a conspicuous casque. Hornbills are omnivorous, but each species feeds predominately on fruits or small animals. Many hornbills are important seed dispersers and benefit the forest ecology. During the breeding season, the female enters a nesting cavity, usually in a large hardwood tree. she seals herself inside the cavity in the majority of species and stays there for much of the nesting cycle while the male brings food to her and her young. Most hornbill species are forest birds, dependant on large expanses of primary tropical rainforest for habitat, while some inhabit drier savanna, but all are vulnerable to disturbance and habitat loss.