Microhabitat selection by feral ferrets (Mustela furo) in a pastoral habitat, East Otago, New Zealand

The spatial distribution of feral ferret (Mustela furo) activity and denning were studied using ink-print tracking tunnels and radio-tracking within pastoral farmland containing a mosaic of grazed (developed and semi-developed) and ungrazed pasture, scrub, tree plantation and scrubby fence lines at Palmerston, East Otago, South Island, New Zealand. Ferrets concentrated their activity in grazed areas but within these areas they were found more often where herbs, scrub and woody cover were present, and where there was an ecotone between pasture and vegetation cover. Ferrets were more likely to be present close to fence lines. When denning, ferrets selected areas with cover of all types and avoided open pasture areas. Ferrets particularly favoured man-made structures (woolsheds, haybarns, sheds etc.) for dens. The implications of these microhabitat selections by ferrets to wildlife conservation in New Zealand are discussed. Ferrets are a possible vector of bovine tuberculosis (Mycobacterium bovis). Ferrets may transmit tuberculosis to stock via contaminated food or latrines deposited outside den sites (68% of dens were accessible to stock). Concentration of ferret movements along pasture ecotones may be a factor facilitating tuberculosis transmission between possums (Trichosurus vulpecula) and ferrets, and between ferrets and stock.