The Duration of Lactation in Antechinus-Stuartii (Marsupialia, Dasyuridae)

Abstract

Free-living Antechinus stuartii at the Monga State Forest showed almost no variation in date of birth, yet weaning took place over a period of three weeks. Males were weaned slightly earlier and at greater weights than females. When daughters were considered, weaning was delayed in years when breeding density was high, and females with ten teats weaned their young later and at slightly lower weights than females with eight teats. The difference between the two teat phenotypes was not simply associated with increased reproductive investment, as successful eight-teated mothers weaned their young earlier than less successful mothers, and there was no relation between weaning success and date of weaning for ten-teated mothers. Age of mother did not influence weaning weight or date, and mothers tended to wean at the same time in each year of their life. These patterns are discussed in relation to recent debate on the detection of life-history trade-offs in free-living populations.