Coevolution is thought to have led to many small mammal species avoiding the scent marks of their main mammalian predators, as they provide a reliable cue to predation risk. Most support for this hypothesis comes from northern hemisphere predator/prey systems, however, it is unclear whether this avoidance of predator faecal odour occurs in Australia's mammalian fauna, which has evolved in relative isolation from the rest of the world, and is dominated by marsupials rather than placentals. We tested this theory for an Australian system with marsupial and placental predators and prey, that share a long-term (>1 million years) or short-term (<150 years) exposure to each other.The predators were the native marsupial tiger quoll Dasyurus maculatus and the introduced placental red fox Vulpes vulpes. The potential prey were three native rodent species, the bush rat Rattus fuscipes, the swamp rat Rattus lutreolus, the eastern chestnut mouse Pseudomys gracilicaudatus, and the marsupial brown antechinus Antechinus stuartii. Small mammals were captured in Elliott traps with 1/3 of traps treated with fox faeces, 1/3 treated with quoll faeces and the remainder left untreated.The native rodent species all showed avoidance of both tiger quoll and red fox odours whereas the marsupial antechinus showed no responses to either odour. Either predator odour avoidance has not evolved in this marsupial or their reaction to predator odours may be exhibited in ways which are not recognizable through trapping. The avoidance by the rodents of fox odour as well as quoll odour indicates this response may either be due to common components in fox and quoll odour, or it may be a recently evolved response.

Following bushfires in Sydney in 1994 a population of 20–30 common ringtail possums (Pseudocheirus peregrinus) that had been studied for four years was reduced to only one or two animals. In the intervening years population numbers remained at this low level. Four years after the fire, 22 ringtail possums were introduced into the study site and radio-tracked for 30 weeks. Nest usage shifted from predominantly dreys before the fire to an equal amount of time spent in dreys and tree hollows. Proportionally, the mortality due to predation by lace monitors (Varanus varius) and diamond pythons (Morelia spilota spilota) increased. Within 12 months the population returned to only two animals. We conclude that increased predation by native predators, added to continued predation by foxes and cats, has maintained a level of predation beyond a threshold that would allow the ringtail population to re-establish to previous levels.

In Australia many critical weight range (CWR) species are threatened by predation from the introduced Red Fox Vulpes vulpes. Understanding how these prey species respond to native predators such as the Tiger Quoll Dasyurus maculatus, and comparing their responses to foxes is important in understanding why fox predation is such a problem. Many northern hemisphere mammalian species have developed responses to the odours of the main species which prey upon them. The situation in Australia remains unclear. We looked at the effect of scenting traps with the faeces of the Tiger Quoll and the Red Fox on the capture rates of four species of CWR marsupials, the Long-nosed Bandicoot Perameles nasuta, the Southern Brown Bandicoot Isoodon obesulus, the Northern Brown Bandicoot I. macrourus and the Common Brushtail Possum Trichosurus vulpecula. None of these species responded to fox odour. However despite low capture rates, Northern Brown Bandicoots and Common Brushtail Possums were captured significantly more often in traps scented with Tiger Quoll faeces. This indicates that these species may be responding to predator odours, but not with the traditionally expected avoidance. Reasons for why this may be so are discussed.

Feral goats are a significant threat to biodiversity in Australia. However, goats are also harvested by some landholders for commercial benefit and this can lead to disagreements regarding control techniques. In the rangelands of New South Wales, feral goat distribution is closely linked to artificial watering points (AWP) such as tanks and bores. Previous surveys indicated that goat activity was rare more than 4 km from water. We hypothesised that constructing sections of goat-proof fencing in areas where goats were feeding on National Parks but watering on neighbouring properties, such that they had to travel more than 4 km from the AWP to access the park, would result in a significant decrease in goat abundance in these areas. We tested this hypothesis in Paroo-Darling National Park, Gundabooka State Conservation Area and Gundabooka National Park using changes in index (fresh goat dung groups per 100-m transect). We also measured kangaroo dung and ground cover index changes. Twelve months after the fences were constructed, goat dung significantly declined compared with non-treatment areas and the relationship between distance to water and goat dung broke down at the treatment sites. Kangaroo indices were not affected by the fences. The results for bare ground were the same as for goat dung, with significantly less bare ground and a breakdown in the relationship with distance to water at the treatment sites after the fences were constructed, but this was due to a corresponding increase in litter rather than live vegetation. This technique can be a significant tool for protecting biodiversity from feral goats, without removing the potential for neighbouring landholders to harvest the goats. If strategically used to create zones free of resident goats around the boundaries of conservation reserves, it should increase the effectiveness of other techniques such as trapping, mustering and shooting, by reducing post-control reinvasion. Recognition of access to water as an important management tool should substantially improve our management of feral goats in the rangelands.

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