Free Tasmanian Devil by David Owen

lengths to keep other males away from his mating partner, keeping her prisoner in the copulation den with little chance to eat or drink. One thirsty male was observed dragging a female with him from a den to a water source and back to the den. 1 David Pemberton and the Mount William ranger Steve Cronin once monitored a male and female in an underground mating den in the wild. The animals hadn’t moved from it for eight days and nights, so, wondering if they had died, Pemberton dug a narrow hole through to the burrow and put his arm down, holding a small mirror. His colleague shone a torch onto the mirror, which revealed a threatening set of bared devil teeth.
    However, the intensity of male competition generally ensures that during a normal breeding season males breed with more than one female. Menna Jones’ studies of breeding indicate that females can be selective, and this means that in combination with multiple sperm donors the female optimises her chances of delivering the best available genetic offspring.

    At birth, Tasmanian devils are tiny, as shown by these four newborns on a coin.
(Courtesy Nick Mooney)
    At birth a Tasmanian devil is no larger or heavier than a split pea. A prime four-year-old male is some 15 000 times heavier, at about 11 kilograms. (In comparison, from birth to maturity the average domestic cat increases in weight about 20-fold.) At six years the male will be dead, having sired perhaps sixteen offspring. An adult female, weighing about 7 kilograms, has on average four breeding seasons, producing about twelve offspring during her lifetime. The mating season is three weeks; pregnancy lasts just eighteen days; the young are dependent on their mother for at least nine months, which means the female then has little time to herself before the next mating season. This demanding cycle means devil populations can theoretically double in size each year, an excellent safeguard against high mortality in both juvenile and adult populations.
    A female devil has four nipples in her marsupium and litters of three or four pups are common, which helps balance out the high juvenile mortality rate. David Pemberton found a healthy 80 per cent of two-year-olds carrying pouch young during his fieldwork study. The mother stands to give birth. Twenty or more tiny embryos leave the womb and travel up to the backward-opening pouch in a stream of mucus. The first arrivals clamp to the teats, which swell in their mouths, so that the newborns become firmly attached to their mother. This ensures they do not fall out of the pouch and is an important survival factor.
    Devils are usually born in mid-April, that is, mid-autumn, ensuring they won’t be weaned and have to face the world alone until long after Tasmania’s challenging winter has passed. DFTD, however, has produced a dramatic shift in reproductive behaviour, with a scatter of births across the seasons rather than

    Baby devils begin to grow fur when they are twelve weeks old. Their sturdy tail is as long as their torso and has important functions including balance, storage of fat and communication. (Courtesy Collection Tasmanian Museum and Art Gallery) exclusively in autumn, and a high number of males competing for perhaps just one receptive female.
    In 1934 David Fleay managed to breed devils in captivity and wrote a fine, precise account of it:
    In the first days of June four tiny, pink, naked and blind babies each a half inch in length had betaken themselves to their mother’s pouch. Shortly after this the father was removed to bachelor quarters, for the mother now showed resentment at his presence by whining growls which rose abruptly in pitch and volume whenever the male attempted to enter the rock shelter. Early in August at the age of seven weeks the thick-set babies in the pouch had grown to a length of two and three quarter inches. They were still pink and hairless but now it could be seen that their tiny limbs moved actively as they clung