The tiger quoll or spotted-tailed quoll Dasyurus maculatus, a nationally threatened species, is the largest surviving carnivorous marsupial on mainland Australia and the sole surviving member of the genus in south-eastern mainland Australia. Live-trapping and radio-tracking studies at three sites in south-eastern Australia found that tiger quolls were solitary, except when mating, and that male and female tiger quolls occupied very large home ranges, both during and after the breeding season. The mean size of the home range of male tiger quolls (minimum convex polygon (MCP) 1755.4 ha, kernel 3761.7 ha) was significantly larger than the mean size of the home range of females (MCP 495.9 ha, kernel 1113.0 ha). Adult female tiger quolls displayed intrasexual territoriality throughout the year, but they seemed to tolerate the presence of female offspring. Male tiger quolls were not territorial and their home ranges overlapped both with other males and with females throughout the year. Males were recorded regularly moving back and forth between a number of female territories during the breeding season. The spatial organization of the tiger quoll recorded in this study differs markedly from that of the eastern quoll Dasyurus viverrinus and the Tasmanian devil Sarcophilus harrisii, but is similar to that of the western quoll D. geoffroii, northern quoll D. hallucatus and brush-tailed phascogale Phascogale tapoatafa. The spatial organization and home-range size of the tiger quoll dictate that conservation of the species requires management across all land tenures at the landscape level.

The tiger quoll is a large marsupial carnivore that occurs in forested habitat in south-eastern Australia. Three tiger quoll populations were trapped for up to six years and data on population parameters, including size, structure, sex ratio, adult : subadult ratio, weight, breeding characteristics, age and longevity were recorded for each population. Sex ratios (♂ : ♀) varied from 5 : 1 to 0 : 1. Population size and age structure reflected previous mortality events and social organisation traits, with all populations showing signs of instability due to disturbance events. Males did not reach full adult weight until three years of age and females until two years. Mean adult male weight was 2.81 kg ± 0.50 (s.d.) (range 2.0–4.2 kg) and mean adult female weight was 1.73 kg ± 0.22 (s.d.) (range 1.2–2.1 kg). Most females did not breed before two years of age and were recorded breeding up to four years of age. A proportion of females did not appear to breed in consecutive years. Matings were estimated to have occurred between late June and early August and births between mid-July and late August. Pouch litter size varied from 4 to 6 with a mean of 5.38 ± 0.65 (s.d.). The adult to juvenile ratio suggests that the mean number of young weaned per female is probably as low as one or two. Monitoring of four females found that the average number of young weaned was three with a range of 2–4. The maximum age recorded was five years. Population declines were found to correlate with 1080 poison baiting programmes, but not with selective logging.

Understanding migratory requirements is critical for the conservation of diadromous fishes. Tupong (Pseudaphritis urvillii) are diadromous fishes found in freshwater and estuarine regions of south-eastern Australia. Previous studies have hypothesised that mature female tupong undertake downstream spawning migrations from freshwater to the estuary or sea, with a compensatory return of juveniles, and possibly spent fish, back upstream. We applied acoustic telemetry to test this hypothesis. We tagged 55 female tupong in two river systems in Victoria, Australia, and tracked movements for 4- to 6-month periods over 2 years. Thirty-one fish undertook rapid downstream migrations and then appeared to move through the estuary and out to sea between May and August in each year. Migration was associated with relatively high river discharges, and movement from the estuary to the sea tended to occur most frequently during intermediate moon phases. Low rates of movement between September and April suggested that tupong inhabited restricted home ranges outside of the spawning season. The apparently disparate migratory patterns of female (catadromous) and male (non-diadromous) tupong are rare amongst fishes globally. Differential exertion of a range of selective pressures may have resulted in the evolution of sexual differences in migratory modes in this species.

Captive trials were undertaken to determine whether tiger quolls and eastern quolls could detect baits that were either buried or covered with soil following the methods employed in normal buried-poisoned-bait programmes. Both tiger quolls and eastern quolls detected, dug up and consumed buried FOXOFF baits. Consumption trials showed that tiger quolls were capable of consuming 2–3 FOXOFF baits in a single meal and more than three baits overnight. Eastern quolls could consume up to 1.5 baits in a single meal. Field trials were undertaken to investigate whether tiger quolls in the wild could also detect and consume buried baits. Trials with both fresh meat and FOXOFF baits were undertaken at a site near a tiger quoll latrine, using a remote camera to record visits to the site and bait uptake. The results confirmed that tiger quolls in the wild can detect and consume both fresh meat and FOXOFF baits that have been buried or placed on the surface and covered with soil to a depth of 5–8 cm. The results indicate that the buried-bait technique is not specific for introduced predators, and free- feeding may not preclude non-target species from taking buried baits. Reliance on the identification of the species visiting bait stations from tracks may also be unreliable as foxes dug up bait stations searching for baits, even after the bait had been removed, potentially obliterating other tracks.

Analysis of 338 tiger quoll scats from tableland moist forest in south-eastern New South Wales found that the greater glider was the major prey species occurring in 54.1% of scats and contributing an estimated 51.01% of the biomass consumed by tiger quolls. Medium-sized (0.5–5 kg) mammals were the most important prey group by occurrence (53.9%), frequency (66.0%) and estimated biomass contribution to diet (62.93%). Other medium-sized prey taken by tiger quolls included: long-nosed bandicoot, rabbit, brushtail possum and ringtail possum. Macropods and wombats were also present in the scats and had been presumably taken as carrion. There was no significant difference in the diets of male and female tiger quolls. Tiger quolls were recorded hunting greater gliders in their tree hollows during the day, hunting rabbits in their burrows both during the day and at night and were observed eating road-killed macropods and wombats around dawn and dusk.