Free Tasmanian Devil by David Owen Page B

Museum and Art Gallery)
    Young devils, because they are active at dusk, have the advantage of arriving at food sources before the more competitive adults. This, however, puts them into competition with spotted-tailed quolls, which are also active diurnal feeders.
    Feeding devils communicate with each other through a range of visual postures, vocalisations and a suite of chemical signals. It was once assumed that dasyurids made little use of visual communications because they are nocturnal. Devils have night-adapted eyesight and their white chest and rump flashes are distinctly visible at night. Interaction between devils at feeding sites takes the form of a ritualised contest, with the dominant feeder not being displaced until it has gorged itself.
    A devil eats up to 40 per cent of its body weight per meal every two to three days. Eating such a large quantity of food in a short space of time—about half an hour on average—often results in the animal waddling off with a distended belly and lying down not far from the feeding site; a devil in this state is easy to approach. It is likely that the absence of other large predators has facilitated this form of feeding, even during the long period when thylacines were Australia’s largest carnivore. This lends some support to the belief that thylacines ate only choice parts of their prey, leaving the rest to devils and other scavengers.
    Being a scavenger able to digest a wide variety of food matter—flesh, fish, bone, invertebrates, fruit, vegetation—was an advantage to the devil’s survival. It may also be that the thylacine’s narrower food base (and less productive breeding cycle) meant that it existed in comparatively lower numbers, leaving it more vulnerable to changed circumstances (human predation) than the devil.
    The number of devils feeding together is generally determined by the size of a carcass: groups of two to five are common. The first arrival is the dominant feeder (unlike communal hyaena feeding, where the higher ranking clan members feed before subordinates), which makes way for a challenger once it has gorged itself. The size of the carcass affects the extent to which the feeding devil will chase off a challenger: the feeder defends the amount of food it needs, not the entire carcass.
    Satiation, rather than dominance, is the most likely information conveyed by the ritualised interactions. This means all devils, small and large, resident and transient, can feed together. It is an efficient way of sustaining a population.
    David Pemberton was the first to make scientific field studies of devils feeding in the wild. The absence of unrestrained aggression while feeding, and the complex behaviour occurring in its place, was a critical discovery, overturning popular (and some professional) perceptions of the animal, as in this supposedly informed 1984 account of feeding devils by a popular natural history author: ‘They behave like a brawling mob, having, so far as anyone knows, virtually no social organisation or restraining instincts’. 3
    Pemberton recorded only one instance of physical injury in 119 interactions during feeding, with one animal chasing and biting another on the rump. On two occasions he also observed jaw-wrestling, where devils stood on their hind legs with forepaws on each other’s shoulders or chest and their jaws interlocked. The animals vocalised constantly while shaking their heads from side to side. Although there was no obvious physical damage to the animals, the nature of the interaction appeared as if it could have caused extensive damage to muzzles or jaws. On each occasion the defeated animal ran off into the bush with its tail in the air and fur fully erect, with the winner pursuing it and biting its rump whenever it was close enough. 4
    Examination of 150 trapped animals showed that 6 per cent had suffered injuries consistent with fighting during feeding or breeding, showing enough damage to