Dispersal of Juvenile Brushtail Possums, Trichosurus vulpecula, after a Control Operation

In: Wildlife research, Band 24, Heft 3, S. 279

Abstract

Long-distance movements of juvenile brushtail possums
(Trichosurus vulpecula) from three habitats on farmland
in Hawke's Bay, New Zealand, were studied by radio-tracking after a
poisoning operation. In the five years after the possum population on the
study site had been reduced by 90%, the population recovered to about
half its initial density. During that time, about 25% of radio-tagged
juveniles dispersed 2 km or more, a maximum of 12·8 km from their natal
area, with no significantly preferred direction. A greater proportion of males
dispersed than females. All but one of the juveniles dispersing did so before
they were one year old, and most made several moves before settling. The
bimodal timing of dispersal in summer and late winter–early spring
reflected an underlying similar pattern of breeding. A higher proportion of
possums dispersed from the low-density pastoral and cropping habitat than from
the higher-density habitats of swamp and willows. The dispersal behaviour of
juveniles after the control operation differed little from that before,
suggesting that dispersal of possums is not strongly influenced by
density-dependent factors at the natal site.