The Brown Antechinus (Antechinus stuartii) is a small carnivorous marsupial, about the size of a mouse, which belongs to the same family as the Tasmanian Devil and the Quoll. It is widespread throughout south-eastern Australia. Living in eucalypt forests where there is dense ground cover and fallen logs, they make their nests out of dry plant material in natural crevices and protected places, such as hollow logs.

Mostly nocturnal, Antechinus live on a diet of beetles, spiders, cockroaches and other insects they forage for in leaf litter.

MALE MATING FRENZY!

The Antechinus is notorious for its short and intense single mating season. At about 11 months of age, around August each year, males begin a two-week breeding frenzy, going all out to father as many young as possible. In this period each male will mate for about six hours at a time with as many females as it can. Not one male will be left alive at the end!

The stress of their vigorous search, furious mating, and aggressive encounters with other males with whom they compete for females, results in their death. Basically, they shag themselves to death! The females, on the other hand, usually go on to breed a second or third year.

A BABY PER NIPPLE

Female Antechinus do not have a definite pouch, but a number of exposed nipples. The number of nipples varies from 6 in wet areas through to 10 in drier and higher locations. Usually a young is born for each nipple.

All females in an area will give birth within a one or two-day period, after a month’s gestation. Once born in mid-Spring, the young cling on to the nipples for about five weeks, being dragged around under their mother. Despite this being awkward, these hardy little animals usually survive.

After five weeks, the young are left in a nest, where they are suckled until they are about 4 months old. They stay with their mother until the onset of the following winter, when the males begin their frantic mating period, and the cycle begins all over.

5 RESCUED BABIES

Although they are wide-spread and common, Antechinus do not come into care very often. Last spring, however, five orphaned babies did.

The little girl was distraught. Fortunately, her father could see the animals were not mice or rats but Antechinus, and called TVWC.

When they were taken into care, in early November, the babies were still attached to their mother’s teats, making identification easy. Each weighed only 2 or 3 grams, being only about 4 weeks old. The babies were hairless, their eyes closed and their ears pinned back. They looked transparent. [see Photo 1, although by this photo their eyes had started to open and fine fur was growing on their backs and heads]

Three of the babies detached themselves from their dead mother’s nipples that day, and the other two were gently probed from their nipple. Then, each baby had to be fed every three hours, around the clock. It was a fiddly job, trying to get tiny amounts of Kangaroo milk formula – there is no commercially available Antechinus milk! – into their little mouths. But they responded to lapping from a spoon readily. [see photo 2]

Within two weeks their eyes were open and hair was beginning to grow on their back and rump areas. Their weight had increased to between 7grams – Small boy – and 12 grams – Good girl 1. Feeding intervals were increased and the weaning process begun.

Small boy surprised us. He grew and thrived, as did his three sisters. Ironically, it was Fat boy who did not. He began to eat less and less, but appeared bloated. After being in care for four weeks, he died. [see Photo 3]

After two months in care, their cage was placed in the bush behind our house, for a “soft release”. When the cage door was left open, for a day or two they returned to eat food that was left out for them, then never to be seen again.

Hand-raising the Antechinus was an intense but very satisfying process, especially when four of the five survived to be released and considering how tiny the animals were when taken into care.

The hand-raising process involved about one thousand individual milk feeds, with each feed session taking almost half an hour, or two to three hours a day!. All this effort when, on their release, Small boy, at least, only had six months left to live! Still, hopefully, there are many more Small boys in our bush as a result, and the three girls have given birth to a litter or two of five or six babies each. The effort is worth it if it is contributing to diversity in our bush and ensuring the survival of one of Australia’s more unusual and notorious marsupials.

REFERENCES

Dr David Macdonald (ed), The Encyclopedia of Mammals, Andromeda Oxford, 1984.

Ronald Strahan (ed), The Australian Museum Complete Book of Australian Mammals, Angus and Robertson, 1983.

Article and photos by Sue Johnson and Helen Joakim