Food and feeding habits of two sympatric hornbill species (the Great Hornbill ;
Buceros bicornis and the Rufous-necked Hornbill ; Aceros nipalensis) during their breeding season
were studied in Huai Kha Khaeng Wildlife Sanctuary in western Thailand. In 1999, the breeding
season began in January and lasted until June. Two nests of the Great and two nests of the Rufousnecked
hornbill were found. Over 15 species of fruits were eaten by the Great Hornbill and 17 species
by the Rufous-necked Hornbill. The study also found that over 31 animal species were eaten by the
Great Hornbill and over 25 species by the Rufous-necked Hornbill. The Great Hornbill seemed to
prefer figs to non-fig fruits such as Lauraceae, Annonaceae and Myristicaceae which was opposite to
the Rufous-necked Hornbill’s preference. Crabs were the animal food eaten in the highest quantity by
both hornbills. The Rufous-necked Hornbill tended to eat insects more than the Great Hornbill. The
entire breeding cycle of the Great and the Rufous-necked Hornbill took about 101-118 days and 117-
126 days respectively. We found that the Great Hornbill had a higher total food quantity, fruit food
quantity and animal food quantity per day than the Rufous-necked Hornbill but not significantly. The
Great Hornbill had a significantly greater number of meals per day and length of time spent around the
nest tree, while the Rufous-necked Hornbill spent a significantly longer time feeding. This research
provides important information for management of hornbill food resources and hornbill conservation.