A hot environment and one type of prey: investigating why the Grey Falcon (Falco hypoleucos) is Australia’s rarest falcon
Jonny Schoenjahn
+ Author Affiliations
Emu 113(1) 19-25 https://doi.org/10.1071/MU12049
Submitted: 12 June 2012 Accepted: 12 September 2012 Published: 8 November 2012
Abstract
The Grey Falcon (Falco hypoleucos) is a poorly known endemic of inland Australia. It is considered Australia’s rarest falcon and among the rarest Falco species of the world. Current information on the species is largely restricted to opportunistic observations and specimens in wildlife collections. Here I detail information on the breeding and dietary ecology of the species from a continent-wide field study from 2003 to 2011. Breeding was recorded 37 times. The breeding distribution of the species was more appropriately described by climatic categories than by average annual rainfall. All nest-sites occurred in areas of the hottest climate classes. All but two food items identified were birds; the two exceptions were rodents captured during a rodent outbreak in September 2011. This study provides the first coherent set of firsthand data concerning key aspects of the ecology of the Grey Falcon, constituting a valuable resource for future studies of the species. The results presented suggest that the restriction of the breeding distribution of the species to areas of the highest annual average temperatures and its almost exclusively avian diet are likely factors associated with the species’ rarity.
Additional keywords: diet, endemic, Koeppen classification, pellet, raptor ecology.
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