Fat-tailed. White-tailed. Hairy-footed. Australia’s dunnart species come in all shapes and sizes. Dunnarts are nocturnal, carnivorous marsupials that are endemic to (only found in) Australia. They’re sometimes mistakenly called marsupial mice. Though they're about the size of a mouse, they're more like quolls and mulgaras, fellow members of the Dasyuridae family.
The Julia Creek Dunnart (one of the largest) is up to 25cm from snout to tail, and weighs up to 70g. The Lesser Hairy-footed Dunnart is one of the smallest species, weighing a measly 10g!
A dunnart’s tail is often nearly as long as its body and they have big black eyes, long whiskers, large ears and sharp teeth. Their furry coats can be sandy, grey or brown, depending on the species.
There are 19 known species of dunnart. We have 11 different species on our reserves – Charles Darwin Reserve in WA has five species on its own!
Where do dunnarts live?
Dunnarts are found all over Australia, from the tip of Cape York to Tasmania, from the east coast to south-west WA (unusually the Kimberley has very few dunnarts).
The Fat-tailed Dunnart has the widest distribution – it’s found across most of inland southern Australia. Other species, like the nationally endangered Sandhill Dunnart, have a far smaller range – this particular species is only found across less than 500 km2 in three widely-separated populations in the Great Victoria Desert in SA and WA and the Eyre Peninsula.
Dunnarts inhabit a whole host of environments. They live in arid and semi-arid woodlands, heathy forests, coastal ranges, dry sclerophyll forest, mallee scrub and grasslands. Some species live on the edges of paddocks, others thrives in deserts. How? Like mulgaras, dunnarts don’t need to drink at all – they get the water they need from their prey!
While 12 of the 19 dunnart species are considered ‘of least concern’ of extinction, many species have suffered a decline in their distribution, four species – Chestnut, Kakadu, Julia Creek and White-footed (south-east mainland) – are considered Near Threatened and three (Butler’s, Kangaroo Island and Sandhill) are Threatened according to the Mammal Action Plan 2012. Many others are regionally threatened: the Stripe-faced Dunnart, for instance, is considered vulnerable in NSW.
Dunnarts breed in spring, nesting in above-ground nests. The Stripe-faced Dunnart has the shortest gestation of any mammal – only 11 days.
Depending on the species, they have litters of 5 to 10 joeys (young). When born, joeys are smaller than a grain of rice!
Like other dasyurids, they have a fold of skin on the stomach instead of a fully formed pouch. Here, the tiny joeys drink from their mother’s nipples for a month before they’re suckled in the nest for another month.
Dunnarts emerge at night to feed. They’re largely insectivorous, eating grasshoppers, crickets, termites, beetles and their larvae. But they’re not picky eaters, they also munch on small reptiles, mammals, amphibians and spiders. Some species can eat their body weight in a single night!
During times of plenty they store excess fat in their tails, which can takes on a swollen, ‘carrot-shaped’ appearance. When food is scarce they draw on this fat to survive. They can also enter a state of torpor, saving energy by lowering their body temperature and metabolic rate – a kind of short-term hibernation.
During the day dunnarts sleep in hollow logs, under rocks, in soil cracks or in small nests. These nests can be in logs, grass tussocks and grasstrees (Xanthorrhoea spp.). The Hairy-footed Dunnart is so small that it lives in the burrows made by spiders and bull ants!
Being nocturnal helps dunnarts conserve precious water and energy in extreme arid environments. And when it’s cold, dunnart species happily share their nests with each other, and with house mice, huddling together to stay warm. But those mice should sleep with one eye open – dunnarts will eat mice when temperatures warm again!
Dunnarts’ lifespan varies. Fat-tailed Dunnarts only live for 15-18 months, but Lesser Hairy-footed Dunnarts live to five years old.
Habitat loss and fragmentation due to vegetation clearing for agriculture and development.
- Predation by feral predators like cats and foxes.
- Inappropriate fire regimes: that is, fires that are too frequent, intense and extensive. Given a dunnart’s home range can be as small as 50m, wildfires can wipe out an entire population.
- Habitat destruction by feral herbivores like cattle, rabbits and camels.
- The use of pesticides in agricultural areas can kill the insects that dunnarts eat.
What’s Bush Heritage doing?
Eleven different species of dunnart are found on Bush Heritage properties. We have Hairy-footed Dunnarts on Eurardy; Charles Darwin Reserve supports four different species (Fat-tailed, Little Long-tailed, Gilbert’s and White-tailed); Stripe-faced Dunnarts are found on Naree Station and Boolcoomatta; Fat-tailed Dunnarts occur on several properties including Nardoo Hills, Bon Bon, Naree and Eurardy; and Hairy-footed and Lesser Hairy-footed Dunnarts both occur on Ethabuka Reserve.
Across our reserve estate, we protect dunnart habitat by removing stock, preventing habitat clearance and implementing a patchy fire regime, so they can seek refuge in a ‘mosaic’ of vegetation. We also increase the dunnart’s chance of living to a ripe old age by controlling feral cat and foxes.