Visayan wrinkled hornbill  (Aceros waldeni)

Classified as Critically Endangered (CR) on the IUCN Red List (1), and listed on Appendix II of CITES (3).

The Visayan wrinkled hornbill gains its common name from the prominent and wrinkled bony crest, known as a casque, situated on the top of the bill (2). This medium-sized bird has predominantly black plumage, glossed with a green sheen, although there is a large white band on the centre of the tail (4). The male has a striking reddish head, neck and upper breast and a red bill topped by a particularly large 'casque' (4). The facial skin is a bright saffron-yellow (2).

Endemic to the Western Visayan Islands of the central Philippines and historically known from Panay, Guimaras and Negros of that group (5). The wrinkled hornbill today survives only on Panay and Negros (5).

Inhabits closed canopy evergreen forests, although these birds are also reported to use areas that have been selectively logged (2).

Little information on the natural ecology and behaviour of this rare forest bird is known, due to a lack of sightings and research. It is thought that breeding occurs in March on the island of Panay, and eggs and chicks are reportedly collected between May and July (5). Clutch size is estimated at between two and three eggs and nests have been recorded in Shorea polysperma trees, known locally as 'balakbakan' (5), or in disused woodpecker holes (2). Hornbills have an unusual nesting strategy where the female seals herself inside the tree cavity and relies on the male to bring food to her and the developing young throughout her imprisonment; in the case of the wrinkled hornbill this lasts until the chicks are fully fledged (6).

From the few records that exist, the major food component appears to be fruit; birds have been observed feeding on figs, and a flock of 25 to 30 birds were seen to feed in Aglaia trees when they were bearing fruit (5).

Habitat loss in the form of deforestation has been the major cause of a precipitous decline in the Visayan wrinkled hornbill and has resulted in its local extinction from the island of Guimaras (4). Shifting agriculture has cleared vast areas of forest, and development and plantations have also played a part in habitat loss (7). In 1988, it was estimated that only four percent of Negros and eight percent of Panay remained forested (4). These birds have also been hunted for food and for collection for the pet trade in parts of their range, and the isolated, fragments of populations that remain are extremely vulnerable to any chance events, such as the local failure of fruiting trees (4).

In 2001 the Visayan wrinkled hornbill was on the brink of extinction, with only 60 to 80 breeding pairs remaining in the wild (8) (9). Fortunately, effective conservation measures, initiated by the Philippine Endemic Species Conservation Project, (PESCP) saw the number of occupied nest holes on Panay increase to 1,108 in 2008 (9). This was achieved primarily through a highly successful nest guarding scheme involving local communities (8) (9). Although it is not known how many Visayan wrinkled hornbills remain on Negros, if any at all, the success of the conservation measures on Panay offer considerable hope for the future of this species (8).

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the conservation of the Visayan wrinkled hornbill see:

• Philippine Endemic Species Conservation Project:
  www.pescp.org

For more information on this and other bird species please see:

• BirdLife International:
  http://www.birdlife.org