Breeding, Population Dynamics and Habitat Relationships of Sminthopsis dolichura (Marsupialia : Dasyuridae) in Semi-arid Shrublands of Western Australia

Abstract

Demographic data were gathered from two populations of the little long-tailed dunnart, Sminthopsis dolichura, inhabiting semi-arid nature reserves in the Western Australian wheatbelt in order to place the ecology of this species (formerly part of the Sminthopsis murina complex) in perspective. In all respects, S. dolichura is similar to S. murina from south-eastern Australia, and, indeed, to most other species of the Sminthopsis group. High mobility and transiency rates, an extended seasonal pattern of reproduction, relatively rapid development of the young and the probable existence of polyoestry characterise the life history of S. dolichura and most other species within the group that have been studied. These attributes enable a high degree of reproductive flexibility and permit these species to opportunistically invade new habitats and ephemeral post-fire seral stages. The observed sympatry with highly seasonal monoestrous dasyurids of the genus Antechinus is postulated to occur through spatial and temporal selection of different microhabitats, but also suggests that phylogenetic factors may be at least as important as the predictability of climate and food resources in explaining the evolution of different reproductive strategies.