The northern quoll (Dasyurus hallucatus), also known as the northern native cat, the Satanellus, the North Australian native aat or the njanmak (in the indigenous Mayali language), is a carnivorous marsupial native to Australia.

Taxonomy

The northern quoll is a member of the family Dasyuridae, and is often stated to be the most distinctive Australian quoll. It was first described in 1842 by naturalist and author John Gould, who gave it the species name hallucatus, which indicates that it has a notable first digit. This species has sometimes been placed in a separate genus, Satanellus.

There are no recognised subspecies.

Life history

The northern quoll is the smallest of the four Australian quoll species.^[3] Females are smaller than males with adult females weighing between 350-690g and adult males 540-1120g. Head and body length ranges from 270-370mm (adult males) to 249-310 (adult females). Tail length ranges between 202-345mm.

Northern quolls feed primarily on invertebrates, but also consume fleshy fruit, and a wide range of vertebrates including small mammals, birds, lizards, snakes and frogs. They also scavenge on road-kills, around campsites and in garbage tins.

A remarkable feature of this species is that the males show complete die-off after mating, leaving the females to raise the young alone. Females have eight teats in a pouch, but apparently give birth to more than eight young which must wriggle their way to the pouch and compete for a teat to survive.^[4] In a study in Western Australia's Kimberley region, the testosterone levels of males peaked in July, and females gave birth in July or August.^[5]

In the wild, males live for about one year, while the maximum recorded for a wild female was about three years of age.^[3] In rocky habitats, the life span of both sexes appears to be increased to two or three years, and individuals are larger than those living in savanna habitats, possibly due to better habitat and reduced predation.^[3]

Range and habitat

The northern quoll occurs from the Pilbara region of Western Australia across the Northern Territory to south east Queensland. Their historical range extended uninterrupted from S.E Queensland to the Kimberleys in Western Australia.^[6] There are several disjunct populations. This quoll species is most abundant in rocky ranges and open eucalypt forest.

Conservation status

1863 illustration by John Gould

The northern quoll is now absent from many parts of its former range. It has recently been listed as Endangered under Australian Commonwealth legislation (EPBC Act), although it is listed as Near Threatened by the IUCN. Its current major threat is the spread of cane toads, which were originally introduced in Queensland, but have now reached Kakadu National Park in the Northern Territory, and are dispersing east towards Darwin.

Other threats are predation by feral cats and foxes, and the destruction, degradation and fragmentation of the Quoll's habitat due to changed fire regimes, mining, land clearing, pasture improvement and grazing.^[3] Quolls are also susceptible to being run over on roads.^[3]

In two Kakadu study sites, quolls have become extinct at one site and declined from 45 individuals to 5 at the other site. The unconfirmed conclusion to be drawn from this is that the northern quoll will cease to exist in most areas in the Top End of the Northern Territory once the cane toad population completely overlaps the northern quoll's range. There are remnant populations of northern quolls still persisting in Queensland where cane toads have been present for many years. Scientists do not yet understand the mechanism for their persistence; some will focus on this area in future research.

To help protect northern quolls against cane toads a University of Sydney project, revealed in 2010, is teaching them to avoid eating the invasive amphibians through taste aversion.^[7]

References

Cited references

General references