Sminthopsis crassicaudata 

 

NATURAL HISTORY 

The Fat-tailed Dunnart (Sminthopsis crassicaudata) is one of about a dozen species of the genus Sminthopsis which belongs to the family Dasyuridae. This family includes all of the carnivorous marsupials, ranging in size from the largest, the Tasmanian Devil, to the medium-sized Quolls, Phascogale and Kowari, down to the smallest, the Antechinus, Planigale and the Dunnarts. 

The Fat-tailed Dunnart occurs on mainland Australia, west of the Great Dividing Range and south of the Tropic of Capricorn. Within this range they occur in a variety of habitats including open woodlands, shrublands and grass-lands from the southern coast to the arid interior. 

In the wild, this species is primarily insectivorous but has been known to take small lizards and juvenile rodents. As is suggested by its common name, the Fat-tailed Dunnart has the ability to store fat in it's tail. This adaptation allows it to survive during the winter months when food may be scarce. 

Dunnarts like to seek shelter under rocks, in tree stumps or hollow logs and even cracks in the ground.  During the winter months they have the ability to enter a state of torpor (this is a state similar to hibernation) that may last from a few hours up to several days, to conserve their body energy. 

CAPTIVE HUSBANDRY 

The Fat-tailed Dunnart is relatively easy to obtain and can be kept indoors. It weighs about 16 grams (range 12 - 22 grams) and has a head-body length of about 90 mm and a tail length of about 60 mm. Consequently it is the ideal choice for anyone wishing to keep a small native animal, be they a first-time novice or an experienced keeper. A suitable environment would be an empty aquarium appropriately landscaped to accommodate a ground-dwelling carnivorous marsupial. Dry plasterers sand is a good base (as it is not too abrasive on the animals feet), with rocks, tussocks of grass, hollow logs and pieces of bark for the animals to hide under and make their nests. 

Although cages should be as large as practicable, a suitable cage size for a pair of dunnarts should not be less than 900 mm long by 300 mm wide and 400 mm high. A well-fitting, yet well-ventilated lid is essential as part of the cage design. A nest box can also be provided which consists of four walls and a simple, but removable lid. Suggested dimensions could be 100 mm by 80 mm by 60 mm. 

As dunnarts tend to have specific toileting areas, these must be cleaned at regular intervals to maintain a healthy cage environment. However, as dunnarts scent-mark their environment they don’t appreciate too much interference, therefore the rest of the cage only needs a thorough cleaning two or three times a year. 

DIETARY REQUIREMENTS 

Captive diets should preferably consist of a variety of natural live foods combined with commercially available pet foods. A weekly feeding schedule should include good quality tinned cat food (meat varieties only, NOT fish), every other day; Wombaroo Small Carnivore Food (see www.healthy-bird.com) mixed with hard boiled egg or finely ground minced beef once or twice a week; and a small bowl of mealworms, crickets,

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cockroaches and other types of live insects, also once or twice a week. Clean, fresh water should be provided with every new meal. A bowl of dried cat biscuits should be available in the cage at all times as these help keep the animals teeth and gums in good condition. Allow approximately 10 grams of food per non-breeding animal per day and 40 grams for nursing mothers. As dunnarts are not strictly nocturnal, they will sometimes come out during the day to feed. 

BREEDING 

 

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In the wild the Fat-tailed Dunnart has an extended (6 - 8 month) breeding season from June to February.  However, in captivity animals may breed at any time of the year. The gestation period is about 13 days, and while females have 10 nipples, litters usually only comprise 6 - 8 young which are weaned at around 70 days of age. 

Some amount of fighting is normal between the breeding animals and this usually precedes mating. Mating can last several hours and is usually quite noisy and aggressive. The pouch on the female may be examined every 14 days or approximately 14 days after an observed mating.

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This is best done by grasping the base of the tail between the thumb and index finger with the animal on her back  in your hand. The fourth finger is placed across the chest of the animal to restrain her. Your other hand is now free to open the pouch carefully. 

If upon inspection of the pouch, fur is still visible inside, the female is not carrying young. The new-born young resemble tiny red masses, smaller than a grain of rice. The adult male and female should now be separated to prevent the young from being eaten. 

Animals become sexually mature at about 5-6 months of age and under captive conditions can have a life expectancy of about 30 months.