Abundance, Distribution, and Rate of Increase of Feral Goats in Western Australia.

Abstract

Aerial survey of 1.2 million km2 of Western Australia in 1987 and 1990 indicated minimum feral goat populations (± standard error) of 363,000±44,000 and 596,500±41,200 respectively. The observed rate of increase over the three-year period was r = 0.17, corresponding to a finite rate of increase of 18% per annum. In the period between the surveys an average of 187,000 goats were known to be commercially harvested each year. The observed rate of increase is below maximum potential rates of increase predicted theoretically for goat-sized mammals and derived from age-specific fecundity and mortality data for feral goats in South Australia.