Julia Creek Dunnart

## Description

The Julia Creek dunnart (Sminthopsis douglasi ) is a marsupial with a buffy brown upperside and white underside. This dunnart has a body length of 100–135 mm with a tail of 60–105 mm to make a total length of 160–240 mm. Its weight is between 40 and 70 g. The length of the hind foot is 22–24 mm. The species has a dark brown triangle colour from above and below the eye with the point at the nose, and another dark stripe on top of the skull. A healthy dunnart has a carrot-shaped tail filled with fat stores.

## Appearance

The Julia Creek dunnart is a small marsupial that is nocturnal and carnivorous, and is the biggest of the genus Sminthopsis, 19 species of which are found in Australia. It almost became extinct before being discovered in the 1930s. It was rediscovered in 1992 after people thought it had been exterminated by invasive animals such as the domestic cat and the European fox. Populations have increased slightly since that time, as Australians have begun killing stray cats.

## Distribution

The Julia Creek dunnart inhabits the Mitchell Grass Downs, as well as north-western Queensland, Australia in the Desert Uplands. It shelters within the cracking clay soils in the dry season or amongst low grass and shrubs after the summer rain. Its choice of habitat seems due to the density of cracks and holes and in the soil, instead of the season-dependent vegetation cover.

## Behavior

Julia Creek dunnarts are solitary and nocturnal, they shelter deep in cracks in the ground in the day and emerge at night to hunt. They seem to be very mobile and occupy stable home ranges of a size from 0.25 ha to 7.12 ha. This species can induce a hibernation-like state in times of famine in order to survive.

## Diet

Julia Creek dunnarts are insectivores and eat different insects (silverfish, cockroaches, slaters and crickets), skinks, spiders, scorpions, centipedes, and long-tailed planigales.

## Reproduction

Very little is known about the mating behavior in Julia Creek dunnarts. It is known that they breed in spring and summer. They make nests in grass tussocks, within dense cover. Two litters may be produced during an extended season if the environmental conditions are suitable. Gestation lasts 13 days and litters typically number eight. In captivity, females reach maturity at 17–27 weeks but may extend mating into a third year. The males reach maturity from 28–31 weeks, the females maturing earlier then males from the same litter. The later maturity of males may be a means of limiting inbreeding in small populations.

## Population

### Population threats

Exotic predators (especially foxes and cats), grazing by cattle and sheep, and the prickly acacia are major threats to these animals. Further threats include climatic factors, inappropriate fire regimes, and small population size.

### Population number

No estimate of population size is available for this species, but it is very sparsely distributed within its range and scattered. Currently this species is classified as Near Threatened (NT) on the IUCN Red List and its numbers today are decreasing.

### Ecological niche

The Julia Creek dunnarts may affect predator populations, as items of prey.

## Fun Facts for Kids

The Julia Creek dunnart is able to store fat in its tail for food, and when food is abundant their tails will be swollen at the base.

Julia Creek dunnarts are one of the ‘boom or bust’ species, as their population size fluctuates depending seasonal changes.

A 1-day old dunnart in the pouch is about 4 mm (1/6") long, weighing 15 mg (0.0005 oz). It breathes through its skin.

These animals may be able to detect rain through their keen sense of smell. After local rain it has traveled up to 10 kilometers, almost always in the direction of the rainfall.

The Julia Creek dunnart is able to hunt mice and lizards, and young can catch insects when they are just 10 weeks old.