Tropical Topics A n i n t e r p r e t i v e n e w s l e t t e r f o r t h e t o u r i s m i n d u s t r y Dasyurid marsupial carnivores of the Wet Tropics No. 50 October 1998 Quoll woes Notes from the Quolls, which were common two hundred years ago, have suffered badly* since the arrival of Europeans Editor in Australia. At that time they were considered all too common. Considered ‘one of the settlers’ greatest Dasyurids are true marsupial pests’ and the ‘dreaded enemy of poultry’, bounties carnivores. They are not the only were put on their heads. They were even blamed for marsupials to feed on other animals thwarting initial attempts to introduce rabbits into — bandicoots and striped possums, Australia and poisoned with strychnine as a result. for example, eat a variety of insects — but these animals are omnivores intended for foxes and rabbits, whereas the dasyurids are predatory The persecution of quolls was soon regretted as rabbits, as well as rats and and vehicle accidents (quolls are carnivores and eat relatively little attracted to road kills but have plant material. mice, started to become a nuisance. However, the best natural defence terrible road sense) have all against such pests only suffered taken their toll. Then there are Dasyurids have well-developed further as quolls became incidental introduced predators, such as canines (‘eye’ teeth) and other cats, foxes and dogs which dental features found in other victims of rabbit traps and poisons. Then, to make matters worse; an compete with quolls for food carnivores. They are enthusiastic epidemic (possibly toxoplasmosis, as well as killing them — and expert hunters. Researchers are interestingly the eastern quoll, very wary about handling them — spread by cats) appears to have devastated quoll populations at the which is the most terrestrial of the they are not timid and are not slow end of the last century. quolls, now survives only in fox-free to sink their teeth into a finger. Tasmania. In northern Australia, there is also strong evidence that the cane Much remains to be discovered In more recent times habitat destruction has been the main cause toad is causing quoll declines; frogs about dasyurid distributions. If you of continuing quoll declines as land is feature on the quoll diet but toads find a dead one, such as a road kill, it poison them. However quolls may would be much appreciated if you cleared for agriculture and forestry. Destruction by cattle and rabbits of eventually learn to avoid toads — the could freeze it and send it to the vegetation around creeklines — two animals are found together in Queensland Museum or to any DEH places such as the upper Palmerston office. Please record as much identified as prime breeding areas for northern quolls — is almost certainly and the western Atherton Tableland. information as possible about your having an impact. In arid regions, the find as well as your name, address Researchers are trying to work out and phone number. cessation of traditional Aboriginal burning practices which, in the past, how many quolls remain. If you see Many thanks to Daryn Storch and created good conditions for many one please contact Scott Burnett, PO Mike Trenerry who helped with medium-sized mammals, is thought to Box 394, Glasshouse Mountains, QLD this issue. have affected quoll populations. 4518; Ph: (07) 5496 9266 or Mobile: 0408 963 350; Please note In addition, illegal shooting (mainly e-mail: [email protected] that you are welcome to photocopy around poultry pens), continued Tropical Topics. However, if the text destruction by traps and poisons is reproduced separately it must not be altered and must acknowledge the * The eastern quoll, once plentiful, is now probably extinct on the mainland. It Environmental Protection Agency as is found only in Tasmania (15 percent of its former range). The western quoll, the source. Illustrations must not be once found across most of the continent, is reduced to about 6000 in a corner of reused separately without permission. WA (5 percent of former range) while the northern quoll, which occupied a Please contact the editor (details on band stretching across the north, has been reduced to small pockets (25 the back page) if in doubt. percent of former range). The spotted-tailed quoll is the only species still occupying a reasonable proportion of its former territory, although it is not common. Sex, death and infanticide Dasyurids become sexually mature when about one year old but many males (about 20 percent of dasyurid species) do not last longer than one season. The most extreme example is the antechinuses, where the mating season is a Reproduction risks frantic two-week long and fatal act. Preparation for this may begin several months This particular reproduction strategy beforehand. Studies of brown antechinuses have shown that they spend a — where most, if not all, males die considerable amount of their time in communal nests. Up to 20 unrelated animals after mating — is shared by all of mixed sexes mingle in these nests, moving from one to another, presumably to antechinuses, phascogales, and some familiarise themselves with all possible mates in the neighbourhood. (Later, northern quolls. (There seems to be a females with suckling young always nest alone.) high mortality among northern quoll males which live in areas where The short mating season is well synchronised, apparently stimulated by a certain survival is difficult, whereas those in increase in daylight during the second half of winter (July, in northern Australia). more quoll-friendly areas may live for Males travel extensively between communal nests at this time in a hectic mating two, or occasionally three, years.) frenzy. Time is limited — their bodies have manufactured a finite amount of sperm but it is leaking away in their urine. They are keen to put it to better use so the It is rather a risky strategy. Although pressure is on for a male to mate as early and as frequently as possible in the the removal of virtually all males from short season and thus pass on as many of his genes as possible. He will never the population leaves more resources have another chance. As the mating season wears on, males become ever more for the mother and her young, if frantic as they dash around in search of mates. predation is heavy or weather particularly bad, an entire local When a male does catch a female (literally population could be wiped out if no — by the scruff of the neck) copulation young males survive. In the case of usually lasts for over five hours and even phacogales, where densities are up to 12 hours. If the female tries to naturally low, and their woodland escape she is hauled back into position. habitat often fragmented by farmland, This may serve to reduce competition. there is little chance for an area to be Certainly no other male can have access to recolonised. that female during this time — and perhaps the female subsequently avoids Most quolls, planigales and dunnarts other males for fear the experience will be repeated! are more flexible in their breeding patterns, males lasting to breed several After mating (possibly several times with different partners), times. (The spotted-tailed quoll lives death is almost inevitable for the male. With all his attention and energy for an average of three years and may taken up with sex rather than feeding, survive for up to five.) stress hormones (Corticosteroids) strip his body of protein and fat. The result is Planigales and dunnarts are less a breakdown in the animal’s immune seasonal, the former probably system, and death within two weeks. breeding in late spring and summer Males seen at this time are usually here in the north. Females often balding and in very poor condition. (A produce two litters in a year. Dunnarts very few males may survive in very may produce two or three litters in a favourable circumstances — but only season and some seem to breed all a small minority.) year round. Producing up to 10 young at a time their numbers can increase About a month or so later the females rapidly if conditions are right. give birth, the tiny youngsters Dunnarts have some of the shortest attaching themselves to the mother’s gestation periods of all mammals (12.5 teats. They should be safe there — days for the common dunnart from but studies* have shown that the conception to birth). Marathon men mothers sometimes snack on their Most dasyurids engage in extended young. This is not a random case of mating episodes — apart from the the munchies — it seems that sexual antechinus 12-hour marathons, discrimination is at work. First-time Overproduction spotted-tailed quolls have been mothers seem to kill most of the girls but second time round eat the boys. For some reason many dasyurids recorded taking up to eight hours seem to go for overproduction of and planigales over two hours. There may be a good reason for this. their young. Eastern quolls, for Sons grow faster and larger than example, have been recorded giving daughters, requiring more maternal energy, which is perhaps easier for a younger birth to up to 30 babies, each of mother to cope with. After they are weaned, however, sons leave home, whereas which is no larger than a grain of daughters remain in the area — to eventually compete with their mothers during rice, but since the mother has only the next breeding season. If Mum does survive to the next season (many don’t) six teats only the first six to attach that will definitely be her last.