Seasonal changes in home range size and habitat selection by kakapo (Strigops habroptilus) on Maud Island

Abstract

Seasonal changes in home range size and habitat selection of kakapo (Strigops habroptilus) were investigated on Maud Island. Kakapo were radio-tracked at night in each of the four seasons between December 2000 and October 2001. Home ranges were estimated for four adult males, three juvenile males and two juvenile females in each season and for nine females in summer, each based on 20 radio-fixes per season. Home range size varied from 1.8 to 145.0 ha using the minimum convex polygon method. Home ranges were smallest in winter. Habitat selection was determined by overlaying the kakapo locations and home ranges on a vegetation map of the island. For each season selection ratios were calculated for each vegetation community. Pine plantation (Pinus radiata) was selected for in summer, whereas the treeland community dominated by five-finger (Pseudopanax arbereus) was selected for in the autumn. Dense pole stands of manuka (Leptospemum scoparium) and pasture communities were avoided by kakapo.