Reproductive Pattern of Captive Boullanger Island Dibbers, Parantechinus apicalis (Marsupialia : Dasyuridae)

Abstract

The recent discovery in Western Australia of two island populations of the dibbler, Parantechinus apicalis, which is rare on the mainland, has provided an opportunity for further study of this species. Following the finding that all males in an island population died soon after the mating period in March, in contrast to mainland males which survive beyond their first breeding season in both the field and the laboratory, a study of the pattern of reproduction in captive island dibblers was made. Like mainland dibblers, island females were found to be monoestrous, and island males potentially capable of breeding in more than one season. Island dibblers are smaller than mainland dibblers but the estimated length of pseudopregnancy was found to be similar. The results of the study on captive island dibblers, together with observations made on the island population at the time it was discovered, suggest that the 'die-off' of males observed in each of the three years following their discovery may not be an inevitable event, as it is for the males of some other species of small dasyurid marsupials (e.g. Antechinus).