The life-history tactics of mustelids, and their significance for predator control and conservation in New Zealand

Intensive predator control on game estates in 19th-century England is believed to be largely responsible for the decline of two large native mustelids, the pine marten and polecat. Two small, related, species, the stoat and weasel, were also killed in large numbers but are still common in England, and have been introduced into New Zealand. The theory of life-history tactics offers an explanation for the different effects of persecution on large and small mustelids. It also suggests that stoats in New Zealand national parks cannot be exterminated by trapping, and that the first priority for the conservation of rare native birds such as the takahe is active management to stimulate breeding.