Reproductive Traits of 2 Populations of the Common Ringtail Possum, Pseudocheirus-Peregrinus, in Victoria

Abstract

Reproduction in the common ringtail possum in Victoria was seasonal, with the majority of births in late autumn and early winter, and late lactation and weaning occurring in late spring and early summer, when young foliage is most abundant. Births and lactation usually did not occur in late summer and early autumn, a time when many ringtails lost weight and some died, and a time when conditions were hot and dry. The age structure and weight of females in the population appeared to influence the timing of breeding and fecundity, but did not explain all the variation in these parameters observed within and between populations. Early breeding in one population appeared to be associated with a high proportion of multiparous females, resulting from high adult survival. Late breeding of primiparous females may have been due to their low body weights at the beginning of the birth season. Among the multiparous females, some produced litters earlier than others, but these females were not significantly heavier than those which bred later. During individual years, multiparous females which bred early in the season, and which were able to wean their first litter at 5 months old instead of the more typical 6 or 7 months, often produced a second litter in spring but were not heavier or older than multiparous females which bred only once in any one year. The higher frequency of second litters in 1982 than in 1981 at Sandy Point was associated with a higher body weight of females in November 1982.