Breeding and genetic management of captive marsupial populations

Abstract

Numerous marsupial species are held in captive breeding colonies throughout the world for the purposes of research, conservation and education. Research colonies have facilitated the development of model marsupial species, including the tammar wallaby (Macropus eugenii), grey short-tailed opossum (Monodelphis domestica) and fat-tailed dunnart (Sminthopsis crassicaudata), the former two of which have been the subject of extensive genome sequencing projects. These species have played a fundamental role in improving our knowledge of marsupial biology, and much of this knowledge now contributes to the conservation and management of other species. Captive breeding programs have become an integral component of species recovery plans as an increasing number of marsupial species become threatened with extinction in the wild, and display colonies also play an important role in conservation education. Genetics has become an intrinsic component of conservation biology, and an instrumental tool in the management of captive populations. All captive colonies need to be actively managed to maximise the retention of extant genetic diversity, minimise levels of inbreeding and avoid genetic bottlenecks, adaptation to captivity and unwanted introgression, all of which can reduce the fitness of individuals and the evolutionary potential of the population. Successful breeding and genetic management of captive marsupial populations requires a thorough understanding of the reproductive and life history traits of the species. This chapter explores the extent to which these traits influence the retention of genetic diversity in relation to extrinsic factors associated with colony management.