FOOD CONSUMED BY GREAT HORNBILL AND RHINOCEROS HORNBILL IN TROPICAL RAINFOREST, BUDO SU-NGAI PADI NATIONAL PARK, THAILAND

Great and Rhinoceros Hornbills are omnivorous. Food consumed by these two species was studied during the breeding season (January to July of 2003 and 2004) in tropical rainforest, Budo Su-Ngai Padi National Park. The results showed that the Great and the Rhinoceros Hornbills had similar duration of every phase in the breeding cycle, i. e. nest visiting, sealing, incubation, early nestling and late nestling. However, considering the entire breeding cycle, Great Hornbill had signifi cantly shorter cycle (110.6±6.7 days) than that of the Rhinoceros Hornbill (121.7±10.4 days). Total food consumption rate of Great Hornbill was signifi cantly less than (47.0 g/Obs.h.) that of the Rhinoceros Hornbill (62.5 g/Obs.h.), and the diet was comprised of fi non-fi g (41.5%) and animal (4.9%). Proportion of fi the diet of Rhinoceros Hornbill was also signifi cantly higher (72.3%), but similar proportion of non-fi g (23.5 %) and animal (4.2%). Of the total 21 species of non-fi g diet of both Great and Rhinoceros Hornbills in this study, Polyalthia sp. (family Annonaceae) and Aglaia spectabilis (family Meliaceae) dominated fruit food by weight, while millipede dominated animal food. There was no difference in diversity of non-fi g fruit species consumed during all phases between both hornbills except during late nestling. In general, the diet of Great Hornbill has signifi cantly higher diversity than that of Rhinoceros Hornbill. From similarity coeffi cient, it was indicated that they used the same food resources which were mainly available during the study period. This paper was presented at the 5 th International Hornbill Conference jointly organised by the National Parks Board (Singapore) and the Hornbill Research Foundation (Thailand), in Singapore on 22 nd -25 th March 2009.