| File:Writhed-billed Hornbill (Bentley).jpg|
| Aceros waldeni|
This is a critically endangered species. Writhed-billed hornbills reproduce very slowly and thus are unable to survive high hunting pressures coupled with heavy logging of the rainforests. It is presumed extinct on Guimaras and now survives only on Negros and Panay. The current population is estimated at less than 160.
Habitat and behavior
Rainforests with abundant fruit-bearing trees are the natural habitat of these birds. They are noisy and live in small groups.
Writhed-billed hornbills use natural or carved-out hollows in tree trunks for their nests. They reproduce very slowly. In conservation camps and parks, man-made nests made of wooden boxes are being attached to tree trunks for the birds to use.
The binomial or scientific name commemorates the Scottish ornithologist Viscount Walden.
- BirdLife International (2006). Aceros waldeni. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 11 May 2006. Database entry includes justification for why this species is critically endangered