Eradication of feral goats on islands and habitat islands

Abstract

Feral goats (Capra hircus) have been eradicated from 16 offshore islands of New Zealand but remain on a further seven. To achieve eradication, four conditions must be met: all animals must be at risk; there must be no recolonisation; the harvesting rate must exceed the rate of increase of the population; and those attempting the task must believe it possible. These conditions, and the costs and hunting efforts involved, are described for a successful but inefficient campaign, an unsuccessful but efficient campaign, and a long term sustained control campaign that might be changed to an eradication attempt. Six conclusions are reached: policies of eradication are counterproductive unless they are possible; short, intensive campaigns are best; managers should measure and record costs, efforts, and kills to improve planning; cynics are useful if only to check claims of success; campaigns should concentrate on one pest at a time; and eradication campaigns must be funded separately from those requiring sustained control.