NICHE PARTITIONING BY 2 SYMPATRIC GOSHAWKS IN THE AUSTRALIAN WET TROPICS - BREEDING-SEASON DIET

In general, coexisting accipiters show low dietary overlap and clear m orphological separation. However, most studies have been conducted in the Northern Hemisphere. In Australia, the two accipitrid goshawks, th e grey goshawk, Accipiter novaehollandiae, and brown goshawk, A. fasci atus, are relatively similar in size. The diets of the two goshawks we re studied in an area of sympatry, at Abergowrie State Forest, Queensl and, in the wet tropics, during the breeding season. The diet of the b rown goshawk contained more birds than did that of the grey goshawk, w hich preyed more on medium-sized mammals and reptiles. The proportion of insects in the diet was similar in the two species. Grey goshawks p referred terrestrial and arboreal prey to the brown goshawks' more aer ial prey. The grey goshawk took heavier prey on average and had a slig htly more diverse diet. Nevertheless; at 93%, dietary overlap between the goshawks was high. Such high overlap may be possible because of th e high diversity and abundance of prey in the tropics, easing interspe cific competition.