Reproduction in female swamp wallabies, Wallabia bicolor

Abstract

The swamp wallaby (Wallabia bicolor) is a common, medium-sized, browsing macropodid marsupial that is unique in many ways. Relatively little is known about the reproductive biology of this species. Previous studies have proposed that the swamp wallaby has a pre-partum oestrus because the gestation period ( x ¯ -->x = 35.5 days, n = 4) is on average longer than the oestrus period ( x ¯ -->x = 31.0 days, n = 5) and the period from the removal of pouch young (RPY) to mating ( x ¯ -->x = 26.0days, n = 3). In the current study, the period from RPY to birth was confirmed at x ¯ -->x = 31.25 days (n = 4) in captive animals, consistent with a pre-partum oestrus. A growth curve for swamp wallaby pouch young was constructed from the progeny of captive animals to estimate the age and date of birth of young in a wild, culled population in South Gippsland, Victoria, and the reproduction of females in the wild throughout the year was examined. Young were born in every month of the year, with no statistically significant variation in the number of young born in each month. Females did not have a period of seasonal anoestrus and conceived throughout the year. Female swamp wallabies in South Gippsland bred continuously throughout the period of this study.