Gestation period and birth in the marsupial Isoodon macrourus

Abstract

The birth of a litter of two short-nosed bandicoots, I. macvourus, was witnessed and photographed. As mating (between litter mates) had also been observed the length of the gestation period was known. It was between 12 days 8 h and 12 days 11 h-the shortest gestation recorded for any mammal. In the 2 h preceding parturition, when the female was watched continuously, she was not seen to lick the pouch or the urogenital opening. However, just before the first young was suddenly expelled, vigorous licking of the urogenital opening began, the mother being on her side with one hind leg raised. The second young was born about 2 min later. The young appeared to be born free of membranes but had intact allantoic stalks. Although the mother did not lick a path in the hair leading to the pouch she continuously licked around the young as they crawled towards the pouch. The allantoic stalks and the deciduous claws on the fore feet anchored the young to the mother during this journey.