Brushtail Possums (Trichosurus vulpecula Kerr) in a New Zealand Beech (Nothofagus) Forest

Brushtail possums were studied over a period of four years by live-trapping, poisoning and kill- trapping on an altitudinal transect (455-1500 m a.s.l.) in beech (Nothofagus) forest in South Island, New Zealand. There was a single breeding season in autumn in which most females (including 80% of one-year- olds) panicipated. Trap-revealed ranges of adults were up to 1 km long and some immature males dispersed up to 10 km. Capture rates in live-traps were highest in beech/podocarp forest at 455-460 m a.s.l. and declined with altitude. No possums were caught above the treeline (1400 m a.s.l.). Removal of possums by poisoning on a 500 x 500 m grid yielded a density estimate of 0.46/ha in mixed beech forest at 460-650 m a.s.l. The density, weights, reproductive performance, movements and structure of the study population are compared with the results of other studies and some implications for possum control and fur harvesting are briefly discussed.