Dasyurids are an almost unknown creature to many. Carnivorous marsupials are a large and diverse group of animals spread across our continent and New Guinea. There is a remarkable variation in all aspects of the species whether dunnart, planigale or quoll. Partly due to their adaptation to a range of environments from arid dessert to damp rain forest.
Australian carnivorous marsupials
Order : Dasyuromorphia
Family : Dasyuridae. Genus Species : 55 species in 12 genera
Family : Thylacindae. Genus Species : one species in one genus.
Order : Notoryctemorphia. Family : Notoryctidae.
Dasyuridae is largest family of carnivorous marsupials. Emphasis will be given to the Fat-tailed Dunnarts, Quolls & Kowaris, as these are currently the only few species that can be held privately on the Victorian Wildlife schedules. Dasyuridae is a family with diverse species ranging in size from 3 grams to 9 kilograms. There are 68 species in total. 53 occur in Australia and 13 in New Guinea. Two species occur in both regions. 8 are endangered and 6 are listed as vulnerable to extinct. The smallest are planigales, ninqauis and dunnarts. Medium sized are the antechinus, mulgara, kowari and phascogales and the larger and more commonly known species are the quolls and devils.
“Dasyurids are characterised by a biting and cutting dentition with four pairs of pointed upper incisors and three lower pairs; well developed upper and lower canines; two or three pairs of upper blade and lower blade-like premolars and four pairs of upper and lower molars with sharp, shearing cusps.” (Strahan 2002) The species has a relatively short life span. Across the species life span generally increases with size. Animals live longer in captivity than in the wild. More young are produced in the smaller dasyurid species than larger species, the reason for this is not know. Body shape does not differ a great deal across the species with the sight exception of the Kultarr which has very long hind limbs. “In arboreal species the hind foot is broad and has a small, mobile hallux.” (Strahan 2002) The hallux is less developed in species that combine an arboreal and terrestrial lifestyle and is absent completely from terrestrial species. (Hallux - the inner most digit of hind foot). Teats range form 4 to 12 depending on the species. Not all species have pouches, phascogales have teats on abdomen in a circular patch. In other species lactating females develop lower lateral folds on the sides of the mammary area. These folds do not offer much protection for the young.
Smaller dasyurids feed on insects, arthropods and small vertebrates. The larger species feed on mammals and carrion. The more arboreal species like the quoll will also feed on birds. Quolls and Tasmanian Devils have been know to take “prey several times their own body size”. Not a lot is known about the social behaviour of carnivorous marsupials. In captivity they can display random aggression towards other animals. Nesting together outside the breeding season. Many dasyurid species are solitary in the wild and only come together during a mating period. Records of communal nesting (in the wild) of many species are during times when food is plentiful, changing to solitary behaviour when food is scarce. In the wild Kowari’s are reported to show threat displays towards each other rarely making contact. In captivity females will be aggressive to the male during the oestrus period. Observation of relationships of species in captivity is essential as they change quickly.
Dasyurids use a number of reproductive strategies. Antechinus, phascogales and Little red kultarr females are monoestrous with a restricted mating period. This is due to males being reproductively senile and dieing after each breeding season. It is thought the die off is due to “stress associated with social demands of the mating season, a time when males stop feeding, live on their reserves and seek all opportunities to mate.” In some male species during this time “stress hormones reduce the effectiveness of the immune system, allowing them to succumb to parasites of the blood and intestine and to bacteria infections of the liver”. (Strahan 2002). Females usually survive to breed a second season, however reproduction is low. Dunnarts and Kowaris are polyoestrous, males have perennial and extend mating periods. There are suggested sex ratios for keeping dasyurid species in captivity. For Fat tailed Dunnarts a 1:1 ratio is suggested, removing the male after pouch young are discovered due to aggression from the female. Groups of animals have been reported to share a nest, however males where observed fighting with other males. Kowaris should be allowed to nest solitary and introduced as a 1:1 ratio, during the breeding season. For captive breeding, it is suggested that males be introduced to a females already established environment. Breeding success has been achieved when introducing the males to the female when she is in oestrus. Oestrus can be determined by presence of cornified epithelial cell, found in urine collected and viewed microscopically. lternatively behavioural oestrus can been seen in Fat tailed Dunnarts and Kowaris this technique can be utilised instead of urine collection and observed for 1-3 days in kowaris and 2-3 days in dunnarts. With Dasyurid species it is important to consider holding a number of animals and rotate them to maximise breeding opportunities this is practice essential to avoid population die out. Dasyurids are an extremely diverse species, living an a range of environments all with equally diverse requirements in captivity. Due to their short life span they can be a challenging species to keep and maintain via captive populations.