Diet of feral ferrets (Mustela furo) from pastoral habitats in Otago and Southland, New Zealand

Abstract In New Zealand, the ferret (Mustela furo) preys upon, and therefore could be threatening, some endemic species and may be involved in the transmission of bovine tuberculosis (Mycobacterium bovis) to domestic stock. The diet of the ferret was studied from prey remains in the digestive tracts of 277 live‐trapped animals from Otago and Southland. Lagomorphs constituted 77% of the diet by weight and were identified in 65% of the ferrets sampled. Other important items were hedgehogs (Erinaceus europeus), possums (Trichosurus vulpecula), and birds. There were no statistically significant differences in the diets of male and female ferrets except a general trend for females to eat smaller prey items. As lagomorphs are such important prey, rabbit control operations may result in short‐term increased predation on endemic species; and/or increased consumption of species that serve as a source of infection of Tb (i.e., possums and possibly hedgehogs); and/or a long‐term decline in the density of ferrets.