Bucerotiformes

Bucerotiformes is an order of birds that includes hornbills and their allies, originating primarily in tropical and subtropical regions of Africa, Asia, and parts of Europe. The group is defined by a characteristic combination of bill morphology and crest structures, though the four extant families vary in appearance and ecology.

The order comprises four families: Bucerotidae (hornbills), Bucoridae (ground hornbills), Phoeniculidae (wood-hoopoes), and Upupidae (hoopoes). Hornbills are known for their large, often curved bills and, in many species, a prominent casque on the upper mandible. Hoopoes have a distinctive long, slender bill and a raised crest, while wood-hoopoes are small to medium-sized African birds with metallic plumage and elongated bills. Ground hornbills are larger, terrestrial relatives that spend substantial time on the ground in tropical forests and savannas.

Behavior and ecology vary across the group but share some broad traits. Many hornbills nest in tree cavities, with the female entering the cavity and being sealed inside by a wall of mud and saliva during incubation; the male delivers food through a narrow opening. Hoopoes and wood-hoopoes typically forage on the ground or in foliage for a diet that includes insects, fruit, and other small prey. Habitat preferences range from open woodlands and savannas to dense forests, with distribution patterns corresponding to each family's evolutionary history.

Taxonomy within Bucerotiformes reflects both morphological traits and genetic relationships, supporting the unity of hornbills and their allies under a single order. Conservation status varies widely among species, with habitat loss and fragmentation posing ongoing threats to many members of the group.