Hornbills
  Page 234-237  Data summarized from: 
                Softbills:  Care, Breeding and Conservation - Martin Vince 
                Published by Hancockhouse Publishers

	Order: Coraciformes
	Family: Bucerotidae

With their long, decurved bills and omnivorous feeding habits, hornbills are the toucans of the Old World. There are about 48 species, many of which have a prominent casque on top of their bill. This is normally a lightweight, honeycombed (partly hollow) structure, that may help to reinforce the bill or act as a shock absorber while nest cavities are being modified.

Hornbills live in the tropical evergreen forests of Asia and Southeast Asia, and in the forests and savanna of sub Saharan Africa.

They are mostly arboreal and eat large amounts of fruit, especially figs, and may gather in feeding parties of over 100 at fruiting trees. But members of the genus Tockus spend a lot of time foraging on the ground and are fairly insectivorous, while the two ground hornbills (genus Bucorvus) are completely terrestrial and virtually carnivorous, preying upon insects, rats, mice, small birds, eggs and snakes. Hornbills do not drink very much, if at all, and normally obtain sufficient water from their food.

Several hornbill species live in groups, with the members jointly defending a territory and often helping the dominant (alpha) pair to feed their young. However, the majority of hornbills seem to live in pairs, where the birds usually forage independently of each other.

• Size

  The great Indian hornbill, Buceros bicornis, is the largest at 52 in. (130 cm).

  Small species such as the red billed, Tockus erythrorhynchus, and yellow billed, T. flavirostris, measure about 18 in. (45 cm).

  Compatibility

  Given their feeding habits, hornbills are obviously a potential hazard in a mixed collection, with the larger species capable of eating small birds, and all species capable of eating fledglings. Hornbills can be kept with similar sized birds, but generally it is far better to give a pair their own aviary.

  Diet

  Ground hornbills: diet I (see page 56) for carnivores. Other species: diet A (page 51) for meat biased omnivores. A chopped or whole mouse can also be added to the diet every 2 or 3 days, and more often to help achieve breeding condition. Hornbills swallow their food whole, so it is important to provide foods they can pick up and swallow easily—chop fruits and meats into bite sized pieces.

  Management

  Hornbills are robust and impressive birds that are fairly easy to keep. The smaller species do not require particularly large aviaries although the bigger hornbills should certainly be given as much space as possible.

  In temperate climates, large hornbills can live outdoors year round, and do not need any heat if they are given a good quality, frost free house. But the smaller species tend to be less hardy and should be shut into a heated house during wintery weather.

  Breeding

  Sexing: great Indian, dimorphic. Male, red eyes; female, white eyes. Yellow billed, monomorphic. Red billed, monomorphic. However, the male may have more black on lower mandible.

  Eggs: small species lay up to 6 eggs; large species lay 2 eggs. All species lay white eggs.

  Incubation: small species approximately 25 days; large species approximately 45 days.
  
  

  Pairs do not always live together amicably, but if all is well, increased vocalizations, displaying, courtship feeding and beak clacking should be the prelude to breeding. Hornbills nest in cavities in trees or rock work. In captivity, nest boxes (up to 2 m tall for large species) are usually accepted and can be enhanced by fixing bark pieces to the exterior; or an old tree trunk can be used, once it has been excavated to make a large cavity.

  The nesting female must be able to easily look out of the nest cavity; this helps her to see and dispatch predators, and it also allows the male to pass food to her. To meet this requirement the cavity should contain a sufficient depth of wood shavings, to which the adults may add leaves, flowers, grasses or even small rocks. If the log is soft or rotten enough, the birds will probably add their own substrate by hammering the cavity roof and walls.

  The shape and size of the cavity entrance hole is also very important. The hole should only be slightly wider than the birds' shoulder width, and of an upright, oval shape. This is because the female of all species, except the ground hornbills, is sealed into the cavity by a wall of feces, sticky fruits, nest debris and mud. If the hole in the nest log is too wide, the birds will be unable to plaster it in and breeding will not take place. But if all goes well, the female is plastered into the cavity and fed by the male through a narrow slit.

  In the wild, ground hornbills also use tree cavities. However, in captivity such birds cannot usually fly (having been pinioned or wing clipped) and need assistance to breed. Captive birds have been known to nest on the ground behind a large log. But normally a box or tree cavity is provided, and stood on the ground or fixed slightly above it. Ground hornbills do not mud in the entrance hole as with all other hornbills; the shape and size of the hole is therefore not as important and can be fairly large.

  In most species of large forest hornbills, the females stay in the nest until the chicks are ready to fledge. But with other hornbills (such as Tockus species) the female emerges far earlier to help gather food for the growing family. At this point the young reseal the hole themselves, using feces and food remains.

  Incubation starts with the laying of the first egg; and with small species (that have as many as 6 eggs) this can mean an age difference of well over a week between the oldest and youngest chick. The older chicks therefore have the best chances of survival, unless there are birds from the previous year's breeding that can help rear the new family. Even species that only have 2 eggs may fail to rear both chicks, and in captivity it can be very beneficial to consider hand rearing the youngest bird or birds.

  When chicks are in the nest, special foods are not necessary. But be sure to provide plenty of soft foods such as juicy fruits, large insects, and chopped and whole pinkie mice. All should be dusted with a multivitamin and mineral supplement, and chopped smaller than usual so that the chicks can safely swallow them.