Publications of the Nuttall Ornithological Club, Number 13.

This study on the taxonomy, zoogeography, and ecology of predatory birds has two themes. The first is the question of whether Gause's principle, that two species with closely similar ecology cannot survive in the same habitat, holds true for birds. The application of this principle means that two closely related sympatric species must differ in ecology if they are to co-exist. The second underlying theme is that study of any group of avian predators, such as the genus Accipiter, will provide information on the principles governing the distribution of terrestrial animals in general. Furthermore, it may be presumed that the vicissitudes of the environment in the recent geological past are reflected in the distribution of the species Accipiter.

Forty-three species of Accipiter are recognized here:
Pied Goshawk, Accipiter albogularis, Shikra, Accipiter badius, Bicoloured Hawk, Accipiter bicolor, New Britain Sparrowhawk, Accipiter brachyurus, Levant Sparrowhawk, Accipiter brevipes, Nicobar Sparrowhawk, Accipiter butleri, Chestnut-flanked Sparrowhawk, Accipiter castanilius, Collared Sparrowhawk, Accipiter cirrocephalus, Semicollared Hawk, Accipiter collaris, Cooper's Hawk, Accipiter cooperii, Rufous-necked Sparrowhawk, Accipiter erythrauchen, Brown Goshawk, Accipiter fasciatus, Frances's Sparrowhawk, Accipiter francesii, Northern Goshawk, Accipiter gentilis, Sulawesi Goshawk, Accipiter griseiceps, Gundlach's Hawk, Accipiter gundlachi, White-bellied Goshawk, Accipiter haplochrous, Moluccan Goshawk, Accipiter henicogrammus, Henst's Goshawk, Accipiter henstii, Imitator Sparrowhawk, Accipiter imitator, Slaty-mantled Sparrowhawk, Accipiter luteoschistaceus, Madagascar Sparrowhawk, Accipiter madagascariensis, Black-mantled Goshawk, Accipiter melanochlamys, Meyer's Goshawk, Accipiter meyerianus, Little Sparrowhawk, Accipiter minullus, Small Sparrowhawk, Accipiter nanus, Eurasian Sparrowhawk, Accipiter nisus, Grey Goshawk, Accipiter novaehollandiae, Ovampo Sparrowhawk, Accipiter ovampensis, Grey-headed Goshawk, Accipiter poliocephalus, Grey-bellied Goshawk, Accipiter poliogaster, New Britain Goshawk, Accipiter princeps, Vinous-breasted Sparrowhawk, Accipiter rhodogaster, Fiji Goshawk, Accipiter rufitorques, Chinese Goshawk, Accipiter soloensis, Sharp-shinned Hawk, Accipiter striatus, Tiny Hawk, Accipiter superciliosus, African Goshawk, Accipiter tachiro, Spot-tailed Goshawk, Accipiter trinotatus, Crested Goshawk, Accipiter trivirgatus, Besra, Accipiter virgatus, Reichenow/Bürger's Sparrowhawk/Chestnut-Shouldered Hawk Accipiter buergersi.