Life history variation and reproductive success in the common brushtail possum, Trichosurus vulpecula

摘要: Life history theory aims to describe and explain patterns in the life cycles of organisms relate these intrinsic extrinsic influences. The an organism is commonly defined as a set co-evolved strategies that directly individuals genetic fitness, lifetime reproductive success (LRS) survival. great majority research on variation mammals has concentrated placental mammals, while marsupials have been largely overlooked. This thesis investigates variation, influence this strategy success, among arboreal marsupial, common brushtail possum (Trichosurus vulpecula). A population T. vulpecula was studied from 2001-2004 Magnetic Island, north Queensland; censused each month by live-trapping. Demographic changes were modelled using capture-mark-recapture data. size remained stable over study period there little temporal recruitment or Island displayed traits similar those reported for other populations species. (>80%) females began reproduce at age two main birth occurred autumn months April May. Some went produce second young spring, after successfully raising first. Males became sexually mature three. Survival, body mass condition declined both males six, although declines more pronounced males. Variation strongly related differences female success. In terms somatic investment, older invested significantly into individual offspring than younger females; also gave earlier season likely spring cohort. Maternal influenced sex ratio; young, primiparous male females, regardless their older, multiparous give when good condition. The extent biased sexual dimorphism extremely variable 11 northern Australia. Dimorphism seasonality breeding, being greatest where births all year round. Mean possums decreased with increasing density, no effect density mass. There some evidence degree breeding synchrony within populations, particularly locations seasonal climate. In population, mating effort varied considerably lost during did males. indication demonstrated age-specific behaviour, which may be experience. The results my show are phenotypically plastic. Age-specific found associated trade-off between current future reproduction. Increased appears entail significant costs decline survival, Variation allocation most probably adaptation maximise LRS. Male survival five compared direct cost adult.