GROWTH-RATES OF THE BANDICOOT ISOODON-MACROURUS AND THE BRUSHTAIL POSSUM TRICHOSURUS-VULPECULA

Although the bandicoot Isoodon macrourus and the brushtail possum Tric hosurus vulpecula give birth to similar-size young, about 200 mg, the pouch young of the bandicoot grow more quickly than those of the possu m. The bandicoot is weaned at 59 days when the body weight is between 90 and 250 g. A young possum weighs about 20 g at Day 60 and between 7 80 and 1031 g when weaned at Day 170-180 post partum. The body weight of both species has been described previously as a continuous curve ex pressed by a quadratic equation. In this study, instead of assuming th e growth curve to be continuous, the growth curve has been expressed a s two components. The growth rates of both species were similar from b irth until Day 12 post partum; the bandicoot then had a faster growth rate. The results from iterative analysis indicated a change in growth rate at Day 30 (data for Days 31 and 32 were missing) and Day 96 post partum for the bandicoot and possum, respectively. Thus, both marsupi als showed a change in growth rate as hair appeared, eyes opened and t he young first left the pouch.