Population biology of small mammals in Pureora forest park .1. Carnivores (Mustela erminea, M. furo, M. nivalis, and Felis catus)

Populations of four species of carnivores were sampled over the five years 1983-87 at Pureora Forest Park, by regular three- monthly Fenn trap index lines supplemented with occasional control campaigns by shooting and additional traps. Stoats were the most frequently collected (63 captures), followed by weasels (18), cats (15) and ferrets (13). Stoats ranged throughout the mosaic of forest types but especially the older exotic blocks, hunting rabbits, rats, possums and birds. The mean age of 55 stoats trapped was 15 months, and their maximum life span about 5 years. The age-specific mortality rate of first year stoats was about 0.76, and the proportion of older stoats (>1 year) declined from 52% of 21 killed in summer/autumn of 1983 to 27% of 22 killed in the same seasons of 1984-87. Weasels were collected mainly from habitats favouring mice, such as a young plantation and the road verges, and 40% of 15 non-empty weasel guts contained mice. Cats and ferrets hunted the native forest blocks where their main prey, rats and possums, were abundant. The body sizes and reproductive patterns of mustelids at Pureora were similar to those recorded in podocarp-broadleaf forests elsewhere in New Zealand.