for providing expert advice during the post-workshop review stage. We thank the experts involved in the New Guinea assessment workshop, for their information on species with distributions spanning Torres

The acceptability of three types of non-toxic predator baits to a variety of indigenous non-target species was determined in the laboratory. The bait-types tested were: Dried Meat Bait (DMB), Probait and two sizes of FoxOffTM baits (30 g and 60 g). The potential poisoning risk, if the baits had been toxic, was calculated for each species from their consumption of non-toxic bait and their sensitivity to 1080. Three species consistently sampled baits; Dasyurus geoffroii, Trichosurus vulpecula and Rattus fuscipes. Where species have had exposure to fluoroacetate-bearing vegetation, their consumption of bait and their level of tolerance to 1080 was such that only 2 of 15, 4 of 15, and 3 of 6 species were considered to be potentially at some risk from toxic DMBs, Probait, and FoxOffTM baits, respectively. In contrast, and mainly because of their lower tolerance to 1080, the theoretical risk for those species without evolutionary exposure to fluoroacetate-bearing vegetation was such that 6 of 12, 8 of 12, and 8 of 9 species theoretically face a high or moderate risk from 3-mg DMBs, Probait, and FoxOffTM baits, respectively. We emphasise, however, that theoretical risk does not necessarily equate to a practical risk, and these results are best used to determine which non-target species should be monitored at the population level during predator-control operations. Factors affecting the potential risk to non-target indigenous animals, and some cautions when extrapolating data from laboratory-based studies to the field situation, are discussed.

Faecal oestradiol-17β levels were monitored for three months during the breeding period in six female chuditch (Dasyurus geoffroii) held in a captive colony. Four of the females mated and gave birth to young. One female mated once but did not conceive and the other female did not mate. Peaks in oestradiol concentration, up to 9 ng g–1 of dried faecal mass, were observed during the period when urogenital swabs were dominated by cornified epithelial cells. Multiple peaks of oestradiol were also observed in the female that did not mate, suggesting that the chuditch may be a reflex ovulator. Monitoring of faecal oestradiol levels did not enable oestrus to be determined with precision, but showed potential for elucidating details of the reproductive biology of this and other marsupial species.

The recognition of sign such as tracks, scats, diggings or burrows is widely used to detect rare or elusive species. We describe the type of sign that can be used to confirm the presence of the greater bilby (Macrotis lagotis) in comparison with sign that should be used only to flag potential presence. Clear track imprints of the front and hind feet, diggings at the base of plants to extract root-dwelling larvae, and scats commonly found at diggings can be used individually, or in combination, to verify presence, whereas track gait pattern, diggings in the open, and burrows should be used to flag potential bilby activity but not to verify presence. A protocol to assess potential activity and verify bilby presence is provided. We provide advice on the application of a plot-based technique to systematically search for sign and produce data for the estimation of regional occupancy. Digging and burrow activity can be readily detected from the air but systematic ground-based assessment to determine the rate of false-presence and false-absence needs to accompany aerial survey. The approach to estimate survey effort to assert bilby absence is also described.

The irregular nature of rainfall in the Australian arid and semiarid zones results in a heterogeneous distribution of resources in both time and space. The mammal species that reside in these regions are uniquely adapted to these climatic conditions, often occurring in naturally low densities and increasing significantly in numbers following major rainfall events. We investigated how these adaptations may influence genetic diversity and gene flow across the landscape in an endangered semiarid/arid-zone marsupial, the sandhill dunnart (Sminthopsis psammophila), from three known populations in southern Australia. Analyses of mitochondrial control region (CR) sequences and microsatellite loci revealed that S. psammophila had maintained similar levels of genetic diversity to other sympatric Sminthopsis species despite its endangered status. There was no evidence for significant phylogeographic structure within the species, but each population was genetically differentiated, based on the frequency of microsatellite alleles and CR haplotypes, suggesting that they should be considered as distinct Management Units for conservation. At a fine spatial scale, no significant genetic structure or sex-biased dispersal was detected within a study site of 240km2. These findings suggest that both sexes are highly mobile, which allows individuals to locate localised resource patches when they become available. We detected evidence of a genetic bottleneck within the population, possibly caused by a recent drought. Our study highlights the importance of maintaining connectivity across the landscape for semiarid- and arid-zone species to enable them to track resource pulses and maintain genetic diversity.