Summary1. The movement of native herbivores onto agricultural land is a key management issue world-wide as they may compete with domestic livestock for pasture and contribute to overgrazing and soil erosion. Eastern grey kangaroos Macropus giganteus are viewed as a problem species in temperate south-eastern Australia, where high-density populations in reserves encroach on nearby farmland. 2. This study examined home range size and use in M. giganteus across different types of land use and in relation to population density and pasture availability. 3. Farmland adjacent to either radiata pine plantations or reserves supporting highdensity populations of M. giganteus was subject to frequent incursions by kangaroos moving onto farmland to rest or graze. However, animals from reserves moved on average only 135 m onto farms. 4. Home ranges of M. giganteus were significantly smaller in the reserves than in farm study sites where population densities were lower. At reserve sites, home range size was limited by higher population densities and limited opportunity for dispersal across surrounding open farmland because of a lack of cover. Home range size was not affected by resource availability. 5.Where suitable vegetation cover occurred on farmland (e.g. woodland remnants or scrub), M. giganteus occurred as resident or roving small mobs. This may be seen by farmers as a disincentive to preserve remnant vegetation as it can provide habitat for unwanted native wildlife. 6. Home range attributes of M. giganteus suggest the species could be controlled by culling. However, recolonization occurs quickly and little is known of dispersal. 7. Synthesis and applications. Population density, presence of cover and reluctance to disperse across cleared landscapes are key factors influencing kangaroo home range size and use of adjacent farmland. Currently, little incentive exists for farmers to preserve remnant vegetation, as it may be regarded as providing habitat for unwanted or 'pest' kangaroos. Given the potential importance of remnant vegetation on private land for the conservation of plants and other species of wildlife, government incentives and compensation programmes may be required to limit land clearing on farms and to encourage improved pasture management.

Adult survival is perhaps the fitness parameter most important to population growth in long-lived species. Intrinsic and extrinsic covariates of survival are therefore likely to be important drivers of population dynamics. We used long-term mark-recapture data to identify genetic, individual and environmental covariates of local survival in a natural population of mountain brushtail possums (Trichosurus cunninghami). Rainfall and intra-individual diversity at microsatellite DNA markers were associated with increased local survival of adults and juveniles. We contrasted the performance of several microsatellite heterozygosity measures, including internal relatedness (IR), homozygosity by loci (HL) and the mean multilocus estimate of the squared difference in microsatellite allele sizes within an individual (mean d (2)). However, the strongest effect on survival was not associated with multilocus microsatellite diversity (which would indicate a genome-wide inbreeding effect), but a subset of two loci. This included a major histocompatibility complex (MHC)-linked marker and a putatively neutral microsatellite locus. For both loci, diversity measures incorporating allele size information had stronger associations with survival than measures based on heterozygosity, whether or not allele frequency information was included (such as IR). Increased survival was apparent among heterozygotes at the MHC-linked locus, but the benefits of heterozygosity to survival were reduced in heterozygotes with larger differences in allele size. The effect of heterozygosity on fitness-related traits was supported by data on endoparasites in a subset of the individuals studied in this population. There was no apparent density dependence in survival, nor an effect of sex, age or immigrant status. Our findings suggest that in the apparent absence of inbreeding, variation at specific loci can generate strong associations between fitness and diversity at linked markers.

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Life-history attributes are described for the mountain brushtail possum (Trichosurus caninus) in mountain ash (Eucalyptus regnans) forest at Cambarville in the central highlands of Victoria, south-eastern Australia. The population was trapped on a regular basis between 1992 and 1995. Population density of T. caninus at Cambarville was high (2.3 animals ha–1). The adult sex ratio was female-biased (1.4 : 1) and the age class structure differed between sexes. There were more adult females than males in very old age classes (those animals assigned to Age Classes 7–9 and exceeding an estimated 10 years of age), whereas there were more males in the young adult cohorts (Age Classes 3 and 4). The breeding season was restricted to March–April, when a single young was produced. A second young was not produced if the first was lost. The survival of young from birth to emergence from the pouch showed strong between-year variation (30–80%). Sex ratios at birth were strongly male-biased (average = 2.6 : 1) but female young were far more likely to survive to advanced back-young stage. Breeding success of females at Cambarville was not influenced by the presence of semi-independent young from a previous year remaining in the natal territory. There was some evidence of senescence in breeding success among females in older age cohorts (Age Classes 7–9) and these animals did not successfully rear young. Many animals were trapped repeatedly at the same place, whereas others ranged over a much wider area (up to 3 ha). There was also considerable overlap between individuals in the spatial location of the areas where they were trapped.

The efficacy of spotlighting as a field survey technique for detecting the greater glider (Petauroides volans) was assessed by comparing the precise location of radio-tracked animals with locations determined simultaneously from spotlighting searches. Radio-collars were fitted to 20 greater gliders in three eucalypt patches embedded within an extensive radiata pine (Pinus radiata) plantation near Tumut in south-eastern New South Wales. Our success rate for detecting collared animals was low, even when survey effort was increased. These findings suggest that spotlighting underestimates actual population size. A further, properly designed study, in different forest types is needed to provide precise estimates of the magnitude of the bias in counts of P. volans obtained by spotlighting.