Feral cats Felis catus are being controlled in alpine areas of Stewart Island/Rakiura to reduce predation on endangered southern New Zealand dotterels Charadrius obscurus obscurus. In order to improve cat control, research on the population regulation and habitat use of cats was undertaken. Cat numbers were limited by the seasonal availability of rats, their primary prey, which contributed 81% of cats’ diet by weight. More cats died of starvation or left their home ranges in late summer or autumn, when rat numbers were low, than at other times. Because of the seasonal depressions in prey availability, cats had very large home ranges of about 1100 ha for females and 2000 ha for males. As a consequence, the population density of cats was very low at around 0.2/km2. Cats were using podocarp-broadleaf forest more than was expected by availability and used subalpine shrubland significantly less than podocarp-broadleaf forest. Selection of forest types was influenced by the need for shelter from wet weather.
|Author||Harper, G. A.|
|Secondary title||DOC Science Internal Series 174|
|Publisher||NZ Department of Conservation|
|ISBN/ISSN||ISBN 0-478-22567-9 / ISSN 1175-6519|