The Tasmanian pademelon, Thylogale billardierii, is a medium-sized wallaby
that adapts well to captivity and, unlike the well-studied tammar wallaby,
is capable of breeding all year round. It may,therefore, be a useful model
species for research into the reproductive biology of macropod marsupials.
This paper presents necessary background data on histological changes in th
e reproductive organs and the rate of embryonic growth during gestation in
T. billardierii. After Day 4 RPY (removal of young from the pouch) the grav
id and non-gravid uteri differ significantly in some histological parameter
s. The corpus luteum becomes active by Day 6 RPY and is fully developed by
Day 14 RPY; it begins to degenerate from Day 19 RPY. Plasma progesterone co
ncentrations through gestation follow a pattern similar to that in the tamm
ar wallaby. There is an early smaller, peak at Day 5 RPY, with plasma conce
ntrations of progesterone then falling until the larger pre-partum peak occ
urs several days before birth.