Coraciiformes Taxon Advisory Group -
Wrinkled Hornbill (Aceros corrugatus)
SSP Manager: Eric Kowalczyk - Woodland Park Zoo
Adult male: crown, back of neck, body, and wings black; face and front of neck white; tail white with broad black base; bill with high wrinkled casque ridge above basal half, yellow, with red-brown base and ridges across lower mandible and with casque deep red; bare circumorbital skin blue; inflatable bare throat skin pale yellow; eyes red; legs and feet black.
Adult female: smaller than male, with casque a low ridge; face and foreneck black; bill paler yellow; circumorbital and throat skin blue; eyes gray-brown; legs and feet greenish gray.
Immature: plumage like adult male for both sexes, but casque undeveloped and bill ridged; bill pale yellow with of orange at base; facial skin pale yellow; eyes yellow with brown tinge; legs and feet blue-gray. Immature female molts into adult face and neck colors at approximately one year.
Kemp (1995) mentions that birds from Sumatra and Malay Peninsula are larger and lists them as A.c. rugosus.
Wrinkled Hornbills are common in North Sarawak, Brunei, and South Sumatra, but are rare in Peninsular Malaysia. In Thailand, they are considered an endangered species. Their near extinct status is from the widespread destruction of the rain forest, the lack of suitable breeding sites, and from being hunted. In Northern Borneo hornbills are hunted for their tail feathers that are used to make traditional costumes for ceremonies. Villagers will pay a high price for a baby hornbill and this trade contributes to the continued decrease of these birds. There are organizations that have adoption projects to protect these birds from being hunted. Collar et. al. (1994) lists this species as "near-threatened".
This species occurs in southern Thailand, Peninsular Malaysia,
the Indonesian islands of Sumatra, Rupat, Payong, Batu, and throughout Borneo. I was recently recorded in southwestern Cambodia. It inhabits lowland primary evergreen forest. Generally uncommon, but fairly common in North Sarawak, Brunei, and south Sumatra; rare in Peninsular Malaysia; endangered in Thailand. As with other hornbills, they are nomadic, coveringlarge areas between foraging areas and roosts. This makes surveys difficult.
Hornbills are usually found in the evergreen forests of the lowlands, up to an altitude of 1000 meters. They can be found in Thailand, Malaysia, and Borneo. The distribution of hornbills can be correlated with the characteristics of the forests such as large trees with natural tree cavities used for nesting and fig-tree density for food. For that reason, hornbills are more likely to be found in unlogged forests.
They have deep echoing calls that sound like harsh kak-kak or deep rowwow or wakowwakowkow and calls can be heard from miles away.
Breeding is usually during the rainy season of December and January. Nest holes are usually located 40-50 meters above ground. After a pre-laying period of 4-6 days, the female will lay an average of two eggs. She can lay extra eggs if the eggs are lost. After a month of incubation, the chicks will hatch. They have pink skin that will turn purple in about 10 days. This is when the female breaks out of the nest, and the male continues to feed the chicks. The chicks will mature and leave the nest after another 65-73 days. The whole nesting cycle takes about four months.
Hornbills eat mostly fruits with numerous small fine seeds such as figs, and small animals such as frogs, lizards, snails, arthropods and young birds. During the nesting period, the male will regurgitate up to 150 figs to feed to his family. These birds do not rely on drinking water because they get water from their food. If the male brings the same food, the female will throw the food back suggesting that he find something else. If the male were never to return, his mate and chicks would starve to death.
This species was first bred in captivity at Audubon Park in 1988 (Sigler and Myers 1992). Presently, there are successful breeding pairs at Honolulu Zoo, San Diego Safari Park, and St. Catherine's Wildlife Center. Lindholm (1999) wrote about a successful reproduction at the Fort Worth Zoo
In Europe, there are several pairs that have bred recently. They are located at Walsrode at Mallorca, Chester Zoo, BirdPark Avifauna (Netherlands), La Palmyre (France), Palmitos Park, and Paultons Park. Jo Gregson at the Paington Zoo Environmental Park is the European studbook keeper for this species.
Aceros corrugatus has the greatest number of living species listed in this studbook (as of early 2011 there are 27.23.1 living in 22 institutions). There are 189 historical records within the studbook. To maintain genetic variation in a self-sustaining captive population, this species will be closely managed as a Species Survival Plan in North America. With the help of the Association of Zoos and Aquariums (AZA) Population Management Center (PMC), the most recent Population Management Plan (PMP) was distributed to participating institutions in December of 2008. The next PMP is planned for October 2011. Of the 51 living individuals, only 23.21.2 birds were included in the PMP. Priority will be to breed wild caught birds that have no living descendants (e.g. pair #76 and 77 and male #35) and to keep a close look at birds that have high mean kinships.