The following description has been taken, with permission, from Softbills.org-
The term softbill is not a scientific one and has been used, and more often misused, in aviculture for numerous years. It is a very misleading title, as many species that fall into the category do not have a soft bill at all; anyone who has ever been attacked by a hornbill can attest to this.
The proper use of the term is in reference to the ‘soft food’ diets which basically fall into the following six categories:
- Carnivorous – those who feed on small mammals, birds or other vertebrates (eg. Kingfishers, Rollers)
- Insectivorous – those who feed on insects and other invertebrates (eg. Bee-eaters, Fly-catchers)
- Omnivorous – those who feed on both animal and plant material (eg. Corvids, Hornbills)
- Frugivorous – those who feed on fruit (eg. Turacos, Fruit Doves)
- Nectarivorous – those who feed on flower nectar (eg. Hummingbirds, Sunbirds)
- Folivorous – those who feed on leafs, petals and other plant material (Turacos, Mousebirds)
This sixth diet type is usually in association with one of the above, as very few birds are solely foliverous, a few species of Galliforme come to mind, however they are not considered to be Softbills.
A more recent definition by Clive Roots is, “Cage and aviary birds with relatively soft bills, which feed upon insects* and soft plant material and whose young are helpless at birth”.
- including other larger animal prey
This latter definition does discriminate against a few species, however as can be seen, the definition is very subjective and can encompass numerous species not generally included in the group.
- The New Softbill Handbook Werner & Steinigeweg
- The Bird Keepers Guide to Softbills David Alderton
- Softbills: their care, breeding & conservation Martin Vince
- Encyclopedia of Softbilled birds Dr. Matthew Vriends
- Softbilled Birds Clive Roots
- The Encyclopedia of Aviculture IN PRESS