Reproduction in Captive Female Brushtail Possums, Trichosurus-Vulpecula

Abstract

Basic reproductive data were collected from a group of wild-caught brushtail possums during three breeding seasons. The mean (±SE) oestrous cycle length, gestation length and interval from removal of pouch young (RPY) to oestrus were 26.3 ± 1.46 (n = 39), 17.1 ± 0.14 (n = 21) and 9.0 ± 0.46 (n = 41) days respectively, agreeing closely with previously published reports. Sperm were first observed in the vaginal smear on days 0 and 1 of the cycle in mated animals, but 27% of matings did not result in the production of a neonate. There was no effect of age of pouch young on the interval between RPY and oestrus but the incidence of mating was greater when pouch young were removed at an early age. In 25 animals examined during an oestrous cycle corpora lutea or Graafian follicles were unequally distributed between left and right ovaries. During the course of the study, four animals were identified in which oestrus was not followed by a luteal phase.