Northern Quoll
The northern quoll is the smallest of the four Australian quoll species. Females are smaller than males, with adult females weighing between 350-690 g and adult males 540-1120 g. Head and body length ranges from 270–370 mm (adult males) to 249–310 mm (adult females). Tail length ranges between 202-345 mm. This tiny marsupial is the size of a small cat. Being the smallest of all 4 Australian species of its genus, this animal is also the most aggressive quoll.
Habitat
They occur in a range of habitats including Eucalyptus open forest, monsoon rainforest and savannah woodlands. The species is most abundant in rocky environments. In north Queensland, it is most common in coastal and/or high altitude rocky areas and in drier habitats of upland tablelands. This species is a generalist, as it occurs in a wide range of habitats. They shelters in hollow logs, rock crevices, caves, and tree hollows. It is mostly a ground-dwelling species, but is also an adept climber.
Diet
Northern quolls feed primarily on invertebrates, but also consume fleshy fruit (particularly figs), and a wide range of vertebrates, including small mammals, birds, lizards, snakes, and frogs. They also scavenge on roadkills, around campsites, and in garbage tins.
Breeding
Northern quolls have a polygynandrous (promiscuous) mating system, where both males and females have multiple mates. They mate from late May to August, after which males show complete die-off, so that females have to raise future offspring alone. Gestation period lasts for 21 - 25 days, yielding 6 - 7 babies per litter on average. However, there have been recorded big litters of up to 17 young. Northern quolls lack a pouch. When giving birth, females develop marginal ridges around their stomach, which cover the newborn baby. By 2 months old, young quolls begin coming out of their rudimentary pouch for short period of time, until complete weaning at 4 months old. The female occasionally leaves the weaned offspring in a nursery den in order to forage during the nighttime hours. Then she moves her young back to the rockier areas. Sexual maturity is reached at 11 months old.
Population
According to the IUCN Red List they are classed as Endangered(E) and they were last assessed on 15th June 2015 and the population is decreasing. The species is locally common, although it currently is undergoing declines across much of its range. Densities of 3-4 females per square kilometre in savannah woodland have been recorded. Several studies suggest that there has been a recent, severe population decline in Kakadu National Park due to cane toads . This species is common in north-western Kimberley, particularly in near-coastal, high-rainfall areas.
Threats
Current threats are uncertain, but the species may be vulnerable to disease, possibly related to the presence of cats. Cats and dogs are known to kill individuals, although they apparently do not like to eat them. Predation is the main cause of mortality in some areas (exacerbated by changes in fire regimes that result in more frequent burning), particularly woodland and forest habitats. There have been recent substantial population declines in the Iron Range (Queensland), Cape York Peninsula, and the top end of the Northern Territory associated with the spread of cane toads and land-use changes. For instance, major declines to regional extinction have been reported for Northern Quolls following cane toad invasion on Cape York Peninsula. Northern Quolls appear to be particularly susceptible to the poison of cane toads, and are killed when they attempt to kill or consume the toads . The species has also disappeared from coastal lowland areas in north Queensland following agricultural and urban development.
Conservation
The Northern Quoll occurs in a number of protected areas. Recommended actions for this species include: monitor abundance and disease status at selected sites across range; undertake additional research into causes of decline. In the Northern Territory, it has been recorded from 15 conservation reserves (Kakadu, Litchfield, Garig Gunak Barlu, Mary River, Manton Dam, Nitmiluk, Umbrawara Gorge, Fogg Dam, Charles Darwin, Black Jungle, Tjuwaliyn (Doglas Hot Springs), Berry Springs, Limmen, Leaning Tree Lagoon, and Howard Springs).