<I>Mustela furo</I>

For two summer/autumn periods (1999, 2000), we studied the movements and survival of feral ferrets (Mustela furo L.) at a site in North Canterbury that had been previously subjected to intensive control of ferrets. Movement distances of juvenile ferrets from the place of initial to final capture were generally low (median = 1.2 km) though variable [mean = 2.5 ± 1.0(±S.E.M.), range 0.1-21.7 km]. The estimated instantaneous mortality rate of juvenile ferrets was high (mean = 0.8 per year), though imprecise (95% C.I.

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.

We monitored the behaviour of 62 radio-collared ferrets and 25 radio-collared cats in dry, tussock grassland habitat in New Zealand's South Island. The total home range of adult male ferrets (102 ± 58 ha, mean ± 1 s.d.) was marginally greater than that of females (76 ± 48 ha), and averaged 90 ± 55 ha. Male ferret core ranges (27 ± 15 ha) were larger than those of females (16 ± 8 ha). Adult cat home ranges were similar between sexes, and were larger and more variable than those of ferrets (225 ± 209 ha). Core range size of cats was similar between sexes and averaged 54 ± 24 ha.

This study reports the diet of feral ferrets (Mustela furo) in a pastoral habitat, East Otago, South Island, New Zealand. Rabbits (Oryctolagus cuniculus) were the most common prey of ferrets, occurring in 86.7% of seats, but birds (12.4%) and invertebrates (11.3%) were also frequently eaten. Female ferrets ate more non-lagomorph prey items, especially invertebrates and birds than males. No significant dietary differences were found between juvenile and adult ferrets except in summer when juveniles ate more lagomorph prey.