Sex and age differences in tree cavity dependence in a small arboreal marsupial

Many mammal species depend on tree cavities for shelter and for breeding. Some species may use tree cavities as well as other varied shelters but the extent of their dependence on tree cavities is unknown. One such species is the eastern pygmy-possum (Cercartetus nanus) from eastern Australia which typically shelters alone. I addressed four key questions: i) do different age and sex classes differ in their preferences for small (4 cm diameter) and large (10 cm diameter) cavities, ii) does the availability of large cavities influence female breeding status, iii) does the availability of large cavities influence where adult females and males are detected, and iv) does the availability of large cavities influence survival and abundance? I provisioned two 9-ha plots containing few (≤2 per ha) ‘large’ natural cavities with artificial cavities in different years. When plots were provisioned with small and large cavities breeding females (n = 46) showed a pronounced preference for sheltering i...