Though they look  alike with their large, outlandish beaks, hornbills are an Old World group unrelated to the toucans of the New World. While the stronghold of the toucans is in Central and South America, hornbills are found in sub-Saharan Africa and Asia, with a single species in New Guinea. The two groups of birds are displayed together as they have adapted to their differing environments in similar ways and share the same diet and outward traits.

The toucan’s bill is crisscrossed by many thin bony supporting rods within and encased in a thin horny outer sheath. For hornbills, support for their heavier beaks comes in the fusion of the first two neck vertebrae – they are the only birds to have this structure. This reinforcement is crucial for hornbills usually have a bony keratin-covered casque surmounting their bills. The helmeted hornbill’s casque is a solid block of bone making up 11% of its body weight.

Most toucans have colourful plumage in all shades of black, blue, green, brown, yellow or red with brilliantly coloured stripes or patches on the bill. On the other hand, the plumage pigments of hornbills are melanin-based and therefore comparatively dull. Some species of hornbill resort to preen gland oils to cosmetically enhance the bill, casque and white areas of plumage with red, orange or yellow colour.  The great hornbill is one such example – it colours its casque and feathers with the yellow pigment in its preen gland oil.

All hornbills except ground hornbills nest within tree holes. They are known to plaster the entrance with mud and droppings till only a narrow slit is left. The incarcerated female and chicks rely solely on the male for food. Toucan nesting differs – smaller toucans may take over woodpeckers’ holes. Bigger toucans appear to nest regularly in hollows in decayed tree trunks but they never seal their nests up and both parents may join their young in the nest at night.