Dasyurus Maculatus Research Articles

Home range and activity patterns measured with GPS collars in spotted-tailed quolls

The spotted-tailed quoll (Dasyurus maculatus) is the largest marsupial carnivore on mainland Australia. It usually occurs at relatively low population densities and its cryptic nature makes it exceedingly difficult to observe in its natural habitat. On the mainland the species is also listed as nationally endangered and more information is needed to direct any meaningful conservation effort. In this study we aimed to elucidate quolls’ spatial requirements and activity patterns using GPS collars on 10 males and 4 females. Quolls were predominantly nocturnal but some individuals showed pronounced daytime activity. There was no apparent seasonal shift in the timing of activity. The movement of quolls appeared to be confined to home ranges that were relatively large for predators of their size. Furthermore, males used home ranges about three times as large as that of the smaller females. There appeared to be some spatial segregation between not only females, which have been considered territorial, but also males. Overall, it is likely that the larger areas used by males is partly caused by the sexual dimorphism in body mass that entails differences in prey requirements and spectrum, but probably is also a function of a promiscuous mating system. All of these could explain the observed more unidirectional movement and larger distances travelled per day by males.

Use of motion-activated remote cameras to detect the endangered spotted-tailed quoll (Dasyurus maculatus): results from a pilot study

A survey of the spotted-tailed quoll (Dasyurus maculatus) was conducted in the Watagan Mountains of New South Wales using baited remote cameras. Nine individuals were detected, of which seven occurred at meat-baited sites and two at sites with a general mammal bait. This confirms the expectation that a meat-based bait increases the ability to detect this species using remote cameras.

Corrigendum to: Use of motion activated remote cameras to detect the endangered spotted-tail quoll (Dasyurus maculatus): results from a pilot study

A survey of the spotted-tailed quoll (Dasyurus maculatus) was conducted in the Watagan Mountains of New South Wales using baited remote cameras. Nine individuals were detected, of which seven occurred at meat-baited sites and two at sites with a general mammal bait. This confirms the expectation that a meat-based bait increases the ability to detect this species using remote cameras.

Confirmation of the presence of the spotted-tailed Quoll, Dasyurus maculatus (Dasyuridae, Marsupialia) from the Late Pleistocene King Creek Catchment, Darling Downs, Southeastern Queensland, Australia

Confirmation of the presence of the spotted-tailed Quoll, Dasyurus maculatus (Dasyuridae, Marsupialia) from the Late Pleistocene King Creek Catchment, Darling Downs, Southeastern Queensland, Australia

Confirmation of the presence of the spotted-tailed Quoll, Dasyurus maculatus (Dasyuridae, Marsupialia) from the Late Pleistocene King Creek Catchment, Darling Downs, Southeastern Queensland, Australia

Confirmation of the presence of the spotted-tailed Quoll, Dasyurus maculatus (Dasyuridae, Marsupialia) from the Late Pleistocene King Creek Catchment, Darling Downs, Southeastern Queensland, Australia

Virtual Reconstruction and Prey Size Preference in the Mid Cenozoic Thylacinid, Nimbacinus dicksoni (Thylacinidae, Marsupialia)

Thylacinidae is an extinct family of Australian and New Guinean marsupial carnivores, comprizing 12 known species, the oldest of which are late Oligocene (∼24 Ma) in age. Except for the recently extinct thylacine (Thylacinus cynocephalus), most are known from fragmentary craniodental material only, limiting the scope of biomechanical and ecological studies. However, a particularly well-preserved skull of the fossil species Nimbacinus dicksoni, has been recovered from middle Miocene (∼16-11.6 Ma) deposits in the Riversleigh World Heritage Area, northwestern Queensland. Here, we ask whether N. dicksoni was more similar to its recently extinct relative or to several large living marsupials in a key aspect of feeding ecology, i.e., was N. dicksoni a relatively small or large prey specialist. To address this question we have digitally reconstructed its skull and applied three-dimensional Finite Element Analysis to compare its mechanical performance with that of three extant marsupial carnivores and T. cynocephalus. Under loadings adjusted for differences in size that simulated forces generated by both jaw closing musculature and struggling prey, we found that stress distributions and magnitudes in the skull of N. dicksoni were more similar to those of the living spotted-tailed quoll (Dasyurus maculatus) than to its recently extinct relative. Considering the Finite Element Analysis results and dental morphology, we predict that N. dicksoni likely occupied a broadly similar ecological niche to that of D. maculatus, and was likely capable of hunting vertebrate prey that may have exceeded its own body mass.

The Ecology of Feral Cats in Mesic, Australian Ecosystems (Abstract)

The body of literature on feral cat (Felis silvestris catus) ecology in the arid- and semi-arid areas of Australia is increasing, but less is known about feral cats in mesic environments. Inherent differences between these habitat types, notably habitat complexity, are likely to be affect¬ing the responses of cats to potential competitors and predators. This research seeks to address this dearth of information by investigating the ecology of cats in the mesic agri-ecosystems of north-east New South Wales, Australia. Camera traps will be used to conduct a capture-recapture study of feral cats to estimate cat density based on pelage pattern and morphology, and GPS collars will log information on cat movement. A particular focus of our work is to tease out inter¬actions between feral cats and the endangered native carnivore, the spotted-tailed quoll (Dasyurus maculatus), to shed light on how these similarly-sized mesopredators coexist. Here we will present preliminary data on spatial and temporal use of the habitats by cats in complex habitats, and present hypotheses, based on the current body of predator interaction literature, that will be tested in the coming years.

Further investigation of the blood characteristics of Australian quoll (Dasyurus spp.) species

The Eastern and Spotted-Tailed Quolls are "near threatened" Australian dasyurid marsupials that have undergone significant reduction in their geographic ranges in the past 200 years. Captive breeding and research colonies now exist, allowing further efforts to more fully understand the physiology of these carnivorous species. The aims of the study were to provide a more detailed study of blood chemistry and differential WBC counts for Eastern and Spotted-Tailed Quolls, and to determine the influence by 3 biologic factors. Blood samples were taken from conscious, captive, healthy Eastern Quolls. A small number of samples from Spotted-Tailed Quolls were also available and were included in the study for comparison. Blood chemistry and differential WBC counts were compared to determine season-, age-, and sex-related differences. For many of the analytes, blood chemistry results were comparable to other marsupial ranges, and no significant differences between sexes were detected (P > .05). Seasonal differences were determined for total bilirubin, glucose, creatinine, and potassium concentrations in the Eastern Quoll. Generally, higher concentrations of these analytes were observed in the summer; however, amylase activity was significantly higher in autumn (southern hemisphere). Eastern Quolls one year of age and younger had significantly (P < .05) higher ALP activities than older animals. The normal ranges determined in this study can be used to assess clinical health of quolls and will assist with captive management and future reintroduction programs to the wild.

Wildlife disease ecology in changing landscapes: Mesopredator release and toxoplasmosis

Changing ecosystem dynamics are increasing the threat of disease epidemics arising in wildlife populations. Several recent disease outbreaks have highlighted the critical need for understanding pathogen dynamics, including the role host densities play in disease transmission. In Australia, introduced feral cats are of immense concern because of the risk they pose to native wildlife through predation and competition. They are also the only known definitive host of the coccidian parasite, Toxoplasma gondii, the population-level impacts of which are unknown in any species. Australia's native wildlife have not evolved in the presence of cats or their parasites, and feral cats may be linked with several native mammal declines and extinctions. In Tasmania there is emerging evidence that feral cat populations are increasing following wide-ranging and extensive declines in the apex predator, the Tasmanian devil, from a consistently fatal transmissible cancer. We assess whether feral cat density is associated with the seroprevalence of T. gondii in native wildlife to determine whether an increasing population of feral cats may correspond to an increased level of risk to naive native intermediate hosts. We found evidence that seroprevalence of T. gondii in Tasmanian pademelons was lower in the north-west of Tasmania than in the north-east and central regions where cat density was higher. Also, samples obtained from road-killed animals had significantly higher seroprevalence of T. gondii than those from culled individuals, suggesting there may be behavioural differences associated with infection. In addition, seroprevalence in different trophic levels was assessed to determine whether position in the food-web influences exposure risk. Higher order carnivores had significantly higher seroprevalence than medium-sized browser species. The highest seroprevalence observed in an intermediate host was 71% in spotted-tailed quolls (Dasyurus maculatus), the largest mammalian mesopredator, in areas of low cat density. Mesopredator release of cats may be a significant issue for native species conservation, potentially affecting the population viability of many endangered species.

Population viability analysis shows spotted-tailed quolls may be vulnerable to competition

Competition between carnivores can strongly affect their behaviour, abundance and distribution. Recent analyses suggest a strong likelihood of competition between eutherian predators and the endangered spotted-tailed quoll (Dasyurus maculatus), although experiments are required to confirm this. If competition does occur, what are its likely effects on the long-term survival of spotted-tailed quoll populations? We used population viability analysis (PVA) to predict the fate of a hypothetical quoll population under various scenarios of competition. PVA showed that spotted-tailed quoll populations may be susceptible to extinction when faced with high densities of competitors. Model scenarios simulating exploitation competition and/or intraguild killing greatly reduced the population’s probability of survival, leading in the worst-case scenario to almost certain extinction.

Distribution of the long-footed potoroo (Potorous longipes) and the spot-tailed quoll (Dasyurus maculatus) in the Goolengook Forest, East Gippsland, Victoria

A survey to assess the distribution of two endangered marsupial species, the long-footed potoroo (Potorous longipes) and the spot-tailed quoll (Dasyurus maculatus) in the south and east of the Goolengook Forest Management Block was conducted in September and October 2006. Survey techniques consisted of hair-tubing, camera surveillance, collecting scat of target species and predators, and searching for activity and tracks of the target species. Eleven sites were surveyed. Twenty-eight records of long-footed potoroo were confirmed at nine of the sites, while one spot-tailed quoll record was confirmed from one of the sites. A record of the long-footed potoroo in the eastern Blackwatch Creek catchment extended, by several kilometres, the boundary of the known East Gippsland distribution at the time of the survey. Long-footed potoroos are distributed widely within the study area and are likely to form part of a contiguous population that extends across the Goolengook Forest and into adjacent forest.

Skull mechanics and implications for feeding behaviour in a large marsupial carnivore guild: the thylacine, Tasmanian devil and spotted‐tailed quoll

AbstractExtinction risk varies across species and is influenced by key ecological parameters, such as diet specialization. For predictive conservation science to be effective, we need to understand extinction risk factors that may have implicated recent species extinctions. Diet and feeding behaviour of the large extinct marsupial carnivore Thylacinus cynocephalus or thylacine have long been debated. Improved understanding of the skull's biomechanical performance and its limitations in a comparative context may yield important insights. Here, we use three‐dimensional (3D) finite element analysis to assess aspects of biomechanical performance in the skull of T. cynocephalus relative to those of two extant marsupial carnivores with known diets that occurred sympatrically with T. cynocephalus: the Tasmanian devil, Sarcophilus harrisii, and spotted‐tailed quoll, Dasyurus maculatus. Together, these three species comprised the large mammalian carnivore guild in Tasmania at the time of European settlement. The bone‐cracking S. harrisii produced high bite forces for its size as expected, but the stresses induced were surprisingly high. A higher proportion of cancellous bone in the skull of this osteophage may act to absorb shock but decrease rigidity and hence raise stress. A relatively high bite force and rigid skull characterized D. maculatus, which may allow them to target prey of variable sizes. Compared with S. harrisii and D. maculatus, we found that the skull of T. cynocephalus was least well adapted to withstand forces driven solely by its jaw‐closing musculature, as well as to simulations of struggling prey. Our findings suggest that T. cynocephalus likely consumed smaller prey relative to its size, which may have had implications for their survival.

Diets of sympatric native and introduced carnivores in the Barrington Tops, eastern Australia

AbstractInvasive predators have severe impacts on global biodiversity, and their effects in Australia have been more extreme than on any other continent. The spotted‐tailed quoll (Dasyurus maculatus), an endangered marsupial carnivore, coexists with three eutherian carnivores, the red fox (Vulpes vulpes), feral cat (Felis catus) and wild dog (Canis lupus ssp.) with which it did not coevolve. No previous study has investigated dietary overlap between quolls and the suite of three eutherian carnivores. By analysing scats, we aimed to quantify dietary overlap within this carnivore assemblage in eastern Australia, and to detect any differences that may facilitate coexistence. We also sought evidence of intraguild predation. Dietary overlap between predators was extensive, with the greatest similarity occurring between foxes and cats. However, some differences were apparent. For example, cats mainly consumed smaller prey, and wild dogs larger prey. Quolls showed greater dietary overlap with foxes and cats than with dogs. Intraguild predation was evident, with fox remains occurring in 3% of wild dog scats. Our results suggest wild dogs competitively dominate invasive foxes, which in turn are likely to compete with the endangered quoll.

Diet analysis of mammals, raptors and reptiles in a complex predator assemblage in the Blue Mountains, eastern Australia

South-east Australia has a complex predator assemblage which has historically been vulnerable to introduced species. This is the first Australian field study to analyse samples from members of the families Canidae, Dasyuridae, Strigidae, and Varanidae to describe the diet and diet overlap between these predators. Samples were collected opportunistically and hair and bone analysis was used to identify the content of samples. Wild dogs (Canis lupus) and lace monitors (Varanus varius) predominantly consumed large mammalian prey, which contributed to the high level of diet overlap (Ojk = 0.79) between these two species. Foxes (Vulpes vulpes) and spotted-tailed quolls (Dasyurus maculatus) also had a high level of diet overlap (Ojk = 0.76), a result of their diets containing a high proportion of medium-sized mammals. The diet of wild dogs and foxes showed moderate overlap (Ojk = 0.59), and foxes were more likely to prey on species within the critical weight range than on macropods, which made up a high proportion of the diet of wild dogs. These data confirm that significant diet overlap can occur between predators from different taxonomic classes and further investigation of potential competition will be important to ongoing management.

Why are there so many Spotted-tailed QuollsDasyurus maculatusin parts of north-eastern New South Wales?

This paper explores the question of why the endangered Spotted-tailed Quoll Dasyurus maculatus remains abundant in parts of north-eastern New South Wales, while populations in many other areas have declined or disappeared. Based on a two-year field study of a high-density population, we discuss a number of possible explanations for this pattern. These include high availability of prey (in particular, arboreal mammals), quality and spatial extent of habitat, low density of competitors, and relatively small home range sizes of females compared to those in other areas.We emphasise the importance of maintaining high densities of hollow-bearing trees, which probably help to support prey populations. Managers should also seek to maintain an abundance of fallen timber, which provides shelter and movement pathways for quolls.We hypothesise that the low density of foxes in our study area, along with the large expanse of relatively undisturbed habitat, most likely explains the high abundance of D. maculatus. Howeve...

Advancement to hair-sampling surveys of a medium-sized mammal: DNA-based individual identification and population estimation of a rare Australian marsupial, the spotted-tailed quoll (Dasyurus maculatus)

Context. Enumeration of cryptic/rare or widely distributed mammal species is exceedingly difficult for wildlife managers using standard survey methods. Individual identification via non-invasive hair-DNA methods offers great promise in extending the information available from hairs collected to survey for presence/absence of a species. However, surprisingly few wildlife studies have attempted this because of potential limitations with the field method and genetic samples. Aim. The applicability of hair DNA to identify individuals and estimate numbers was assessed for a rare, medium-sized Australian marsupial carnivore, the spotted-tailed quoll (Dasyurus maculatus). Methods. Hair samples were obtained remotely in the field with baited hair-sampling devices (known as handi-glaze hair tubes) that permit multiple visitations by individuals and species. A hierarchical approach developed and applied to the DNA extraction and PCR protocol, based on single and four pooled hairs of each collected sample, was used to assess genotype reliability (cross-species DNA mixing, allelic dropout and false allele errors) and enumerate the local study population. These results were compared against a concurrent live-cage trapping survey that was equivalent in scale and trap density to enable a rigorous evaluation of the efficiency and reliability of the DNA-based hair-sampling technique. Key results. Of the 288 hair devices deployed, 52 (18%) captured spotted-tailed quoll hair and the majority (90%) of these samples provided adequate DNA to genetically profile individuals at 10 microsatellite loci and a sexing marker. The hierarchical approach provided a feasible way to verify whether cross-species DNA mixing had occurred in the pooled-hair DNA extracts by comparing the results against the independent single-hair DNA extract, and assess genotyping reliability of both DNA concentrations. Fewer individuals were detected using hair-sampling (n = 16) than live-trapping (n = 21), despite hair-sampling occurring over a longer period (40 cf. 26 nights). Conclusions. The population-level information gained by the DNA-based technologies adds considerable value to the remote hair-sampling method which up until the present study had been used to detect the presence of medium-sized mammals. Our study demonstrated the utility of the DNA-based hair-sampling method to identify spotted-tailed quoll individuals and for surveying local populations. However, improvements to the hair-sampling method, such as increasing the density of stations or the provision of a food reward, should be considered to enhance sampling efficiency to allow the enumeration of local populations. Implications. The use of remote hair-sampling devices that permit multiple visitations and do not require daily collection can be feasible and reliable to genetically identify individuals when coupled with appropriate strategies. By combining single- and pooled-hair DNA extracts, a good compromise between laboratory efficiency and data integrity is afforded.

Socio-seasonal changes in scent-marking habits in the carnivorous marsupial Dasyurus maculatus at communal latrines

Scat DNA analyses and monthly monitoring were used to elucidate patterns of latrine use in a free-ranging population of a rare Australian marsupial carnivore, the spotted-tailed quoll (Dasyurus maculatus) Kerr. In all, 132 latrines were identified at large complex outcrops and on bedrock in drainage lines, creeks and rivers at a single woodland site in south-eastern mainland Australia. Annual cyclic variation in scat deposition was found over the two years that latrines were monitored. Peaks in scat deposition on latrines coincided with seasonal social behaviours and differed between sites on outcrops and sites along drainage lines. A marked increase in scat deposition on latrines in drainage lines was recorded during the mating season and at outcrop latrines when females were nursing young. Genetic analyses of scats collected over one breeding season revealed that multiple individuals of both sexes defaecated at latrines. The communal use of latrines during the mating season along with the seasonal patterns of scat deposition demonstrates that latrines are important scent-marking sites that facilitate social communication among individuals of this solitary-living species. The collective evidence indicates that latrines play a major role in aiding reproduction and interindividual spacing.

Field-based evaluation of scat DNA methods to estimate population abundance of the spotted-tailed quoll (Dasyurus maculatus), a rare Australian marsupial

Context. DNA extracted non-invasively from remotely collected scat samples has been used successfully to enumerate populations of a few endangered mammal species. However, scat DNA surveys relying on scent-marking behaviours need to identify if age- or sex-specific variations or seasonal changes in scat scent-marking patterns affect population estimates. Furthermore, owing to the low quantity and quality of scat DNA, a thorough assessment of the technique is needed when it is applied to different species to ensure that individual identification is reliable. Aims. In the current study, microsatellite genetic profiles derived from 208 remotely collected scats of the spotted-tailed quoll (Dasyurus maculatus), a rare Australian marsupial carnivore, were compared with DNA profiles from tissue of 22 live-trapped individuals from the same study area to critically assess the reliability of the non-invasive method to estimate population abundance. Methods. Scat samples were collected at scent-marking sites over 4 consecutive months (April–July 2005), 7 weeks of which overlapped with the trapping program to allow direct comparisons of population estimates. Key results. Combining a multiple-tubes approach with error checking analyses provided reliable genetic tags and resulted in the detection of the majority of the live-trapped population (18 of 22 individuals). Ten additional individuals not known from trapping were also observed from scat DNA. A longer-term sampling regime was required for scats than for trapping to allow direct detection of a large proportion of the population and to provide a comparable population estimate. Critically, the 4-month scat collection period highlighted the importance of performing scat surveys during the mating season when scat scent marking is more frequent, and to avoid sex and age biases in scat marking patterns. Implications. Non-invasive scat DNA sampling methods that rely on scent-marking behaviours need to consider the duration of the sampling period and temporal differences in behaviours by the sexes and age groups to ensure that meaningful population estimates are achieved.

Who's your daddy? Paternity testing reveals promiscuity and multiple paternity in the carnivorous marsupial Dasyurus maculatus (Marsupialia: Dasyuridae)

Female promiscuity is common among mammals but its advantages, particularly for marsupials, remain unclear. Using microsatellite DNA from pouch young of known mothers, we identified the most likely fathers of 25 wild spotted-tailed quolls (Dasyurus maculatus) from six litters. We aimed to determine whether young within the same litter had different fathers, and whether breeding success of males was associated with large body mass (consistent with inter-male competition) or scrotal width (consistent with sperm competition). We also explored the possible influence of promiscuity on relatedness within litters. Finally, we used data on paternity and relatedness to make inferences regarding movement and dispersal. Four litters were sired by more than one male, and three males sired offspring in more than one litter. Known fathers had higher body mass, but not scrotal width, than males of unknown paternity status, suggesting that males may compete for access to females. Sires were less related to dams than expected by chance, and litters with multiple paternity had lower relatedness than litters sired by a single male. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 1–7.

Know thy enemy: Behavioural response of a native mammal (Rattus lutreolus velutinus) to predators of different coexistence histories

Abstract Predation is recognized as a major selective pressure influencing population dynamics and evolutionary processes. Prey species have developed a variety of predator avoidance strategies, not least of which is olfactory recognition. However, within Australia, European settlement has brought with it a number of introduced predators, perhaps most notably the red fox (Vulpes vulpes) and domestic cat (Felis catus), which native prey species may be unable to recognize and thus avoid due to a lack of coexistence history. This study examined the response of native Tasmanian swamp rats (Rattus lutreolus velutinus) to predators of different coexistence history (native predator‐ spotted‐tail quoll (Dasyurus maculatus), domestic cats and the recently introduced red fox). We used an aggregate behavioural response of R. l. velutinus to predator integumental odour in order to assess an overall behavioural response to predation risk. Rattus lutreolus velutinus recognized the integumental odour of the native quoll (compared with control odours) but did not respond to either cat or fox scent (compared with control odur). In contrast, analyses of singular behaviours resulted in the conclusion that rats did not respond differentially to either native or introduced predators, as other studies have concluded. Therefore, measuring risk assessment behaviours at the level of overall aggregate response may be more beneficial in understanding and analysing complex behavioural patterns such as predator detection and recognition. These results suggest that fox and cat introductions (and their interactive effects) may have detrimental impacts upon small native Tasmanian mammals due to lack of recognition and thus appropriate responses.