Tiger Quoll
With males and females weighing around 3.5 and 1.8 kg, respectively, it is mainland Australia's largest carnivorous marsupial, and the world's longest extant carnivorous marsupial (the biggest is the Tasmanian devil). Two subspecies are recognised: One is found from southern Queensland south to Tasmania, the other is found in an isolated population in northeastern Queensland. The tiger quoll is the largest of the quolls.
Habitat
They are found in eastern Australia where more than 600 mm of rain falls per year. Historically, the quoll was present throughout southeastern Queensland, through eastern New South Wales, Victoria, southeastern South Australia, and Tasmania. European settlement has severely impacted and fragmented the quoll's mainland distribution. In Tasmania, the tiger quoll mostly frequents the northern and western areas where rains are seasonal. Tiger quolls were once native to Flinders and King Islands. Tiger quolls live in a variety of habitats, but seem to prefer wet forests such as rainforests and closed eucalypt forest.
Diet
Animals eaten include insects, crayfish, lizards, snakes, birds, domestic poultry, small mammals, platypus, rabbits, arboreal possums, pademelons, small wallabies and wombats. They may scavenge larger prey such as kangaroos, feral pigs, cattle, and dingoes. They do not scavenge as much as the Tasmanian devil. Much of the prey eaten are arboreal. They can climb high into trees and make nocturnal hunts for possums and birds. The flexibility of their diets suggests their prey base is not detrimentally affected by bushfires. When hunting, they stalk their prey, stopping only when its head is up. It then launches its attack, executing a killing bite to the base of the skull or top of the neck, depending on the size of the prey. The quoll will pin small prey down with its fore paws and then deliver the bite. With large prey, it jumps and latches on its back and bites the neck. They may be preyed on by Tasmanian devils and masked owls in Tasmania and dingos and dogs in mainland Australia. It may also be preyed on by wedge-tailed eagles and large pythons. Tiger quolls yield to adult devils, but will chase subadults away from carcasses. Quolls also probably compete with introduced carnivores, such as foxes, cats, and wild dogs. Tiger quolls are also hosts to numerous species of endoparasites.
Breeding
Tiger quolls are polygynous, which means that one male mates with multiple females. They breed in April-July. Gestation period in this species lasts for 21 days, yielding 5 young on average. The babies are then moved to the pouch of their mother, where they continue to grow for the following 12 weeks. Then the mother begins feeding her offspring by bringing food into her pouch. The female does not carry her young on her back. However, the babies tend to rest on their mother and cling on her if threatened. Full independence in reached at 18 - 21 weeks old, while the age of sexual maturity is one year old.
Population
According to the IUCN Red List, the total Tiger quoll population is around 20,000 mature individuals, including small population in north-eastern Queensland, which is estimated to less than 1,000 individuals. Today, Tiger quolls’ numbers are decreasing, and these animals are classified as Near Threatened (NT) on the IUCN Red List.
Threats
The biggest threat to this species is habitat loss as a result of urban development and fragmentation of their range. Furthermore, the situation is compounded by competition with other animals, with which they share similar habitat. On the other hand, the Tiger quolls are hunted by both native and non-native predators, including red fox or feral cats. And finally, these animals are poisoned through taking traps with 1080 poisoning baits, targeting dingoes.
Conservation
Recovery objectives include monitor populations; prevent further habitat loss and fragmentation; minimise any impact that 1080 baiting may be having on the species; undertake public education, especially of private land holders in rural areas, to reduce direct killing.
Population trends should be conducted using repetitive density estimates in a range of habitats across its distribution. Suveys are particularly needed in central and southern New South Wales to complement forest surveys in north-eastern areas. Cage trapping and hair tubing have proved fairly successful in detecting the species if more than one sampling period per site is undertaken. Additional studies should investigate the effects of competition from other predators including feral cats, foxes and dingoes/wild dogs. Habitat use and further study of dietary requirements are also a priority. In Tasmania, monitoring of population densities should be conducted in relation to forestry practices.
Management actions required include continued monitoring of quoll populations; additional survey work in order to locate other quoll populations and to test more rigorously for population distributional limits; experimental removal of cane toads from roads within the optimum habitat of D. m. gracilis and monitoring of effects if any on quoll populations; community extension work in areas where quolls have been, and continue to be, displaced.