Academic literature on the topic 'Dasyuridae Conservation'

Analyses of mitochondrial DNA (mtDNA) and allozymes are used to investigate the population genetic structure, phylogeography and systematics of the fat-tailed dunnart, Sminthopsis crassicaudata. Phylogenetic analyses of control region sequences reveal the presence of two major mtDNA haplotype clades. A survey of the distribution of the two clades using diagnostic restriction endonucleases shows that one clade is restricted to southeast Australia whereas the second clade occupies the remaining central to western range of S. crassicaudata. Allozyme electrophoresis also shows concordant patterns of population structure, with significant differences in allele frequency at three loci between populations in the southeast and northwest. Together, the mtDNA and allozyme data provide evidence that S. crassicaudata consists of two Evolutionarily Significant Units (ESUs). The distribution of each ESU is not concordant with the distribution of the subspecies of S. crassicaudata, and we propose that the current subspecies classification neither reflects the major genetic subdivisions present within S. crassicaudata nor would be appropriate for any future conservation management. The level of divergence between mtDNA clades (3.4%) is indicative of cladogenesis in the Pleistocene and reflects a long-term barrier to maternal gene flow between these two populations. One potential historical barrier was Lake Bungunnia, which persisted in the Murray basin over much of the Pleistocene.

The brush-tailed phascogale (Phascogale tapoatafa) is considered locally rare and vulnerable, despite being found in all mainland states of Australia. It is rarely detected in faunal surveys and the two most immediate conservation requirements are a determination of its current range and clarification of its taxonomic status. Measures of genetic differentiation amongst Phascogale tapoatafa populations in eastern, western and northern Australia were estimated using a partial (348 bp) sequence of mitochondrial DNA (cytochrome b gene). Observed sequence divergence within P. tapoatafa was substantial, with an average of 13% separating the allopatric populations in south-eastern, south-western and northern Australia. In comparison, an average of 16% sequence divergence separated the two currently recognised Phascogale species (P. tapoatafa andP. calura). Thus, Phascogale comprises four highly divergent lineages, suggesting that the genus is more diverse than previously thought. These data indicate that further taxonomic research is warranted.

Fauna translocations are often used for conservation purposes. This has been especially prevalent in the translocation of threatened species in south-west Western Australia. Translocations can fail for several reasons such as stress, disease and predation and, less frequently, homing behaviours of translocated individuals. We report on one of eight chuditch, Dasyurus geoffroii, that was recaptured near the original point of capture 12 days after release at the designated translocation site in George State Forest Block, 14 km to the south. During that period she had lost 12.5% of her body weight, but was otherwise in good condition. It is possible that this event was unique to this individual and the other seven chuditch remained within the translocation site of George Block. However, this species is known to travel long distances and have large home ranges. It is important to determine the propensity of this species to attempt homing after translocation in an effort to determine whether a minimum release distance is necessary.

Quolls are carnivorous marsupials in the family Dasyuridae with characteristic white spots. They are distributed throughout Australia and New Guinea, but uncommonly seen due to their mostly nocturnal solitary nature, and large home ranges. All Australian quolls are listed as ‘near threatened' or ‘endangered' at state, national and international levels, largely due to human-induced threats. Threats include introduced predators, habitat loss through clearing and modifications including changed fire regimes, disease, human persecution, vehicle collisions and accidental or targeted poisoning by humans and cane toads (Rhinella marina). Conservation efforts that have focussed on reducing introduced predators, and minimising the impact of cane toads, have aided some translocations, hence species recovery in some local areas of Australia has occurred. Where species conservation has required captive breeding for translocation, successful captive management has been crucial. We summarise research conducted in captivity on aspects of birth and development, health and disease, and blood and nutrition parameters of quolls, and suggest future directions for research. Further research on captive and wild quoll populations will benefit future translocations, reintroductions and conservation through increased knowledge, improved maintenance and husbandry of captive colonies, and monitoring of wild populations.

Since the turn of the century, a third of the mammal species of arid Australia have suffered a drastic decline in distribution and abundance. Uluru National Park has not escaped the massive loss of mammals, with over 15 species being lost from the Park in the last century, and some, including the brush-tailed possum, Trichosurus vulpecula, becoming locally extinct in the last twenty years (Baynes and Baird 1992, Reid, Kerle and Morton 1993). This suggests that the processes causing the decline are still operating. The mulgara Dasycercus cristicauda, remains extant in the vicinity of Uluru National Park but has suffered extensive range reductions and is believed to be less abundant in areas which it still occupies (Kennedy 1990, Gibson and Cole 1992, Woolley 1995). Very little is known about the field ecology of D. cristicauda and this has hindered the conservation management of the remaining populations. I report here on ecological data collected from a population at Uluru National Park between 1987 and 1990. This information was collected during a study of the effects of fire on small mammals of the area (Masters 1993).

This paper uses a combined morphological, molecular and ecological approach to assess the taxonomic status of Antechinus flavipes leucogaster from Western Australia, and its relationship to A. flavipes flavipes from eastern Australia. Morphological analyses show that A. flavipes leucogaster is smaller and finer than its eastern Australian counterpart in both cranial and dental dimensions. Phylogenetic analyses of partial cytochrome-b sequences showed that A. flavipes flavipes and A. flavipes leucogaster form reciprocally monophyletic clades that have a relatively high level of divergence (approximately 6%). Analysis of the timing of reproduction indicates that the two subspecies show opposite responses to latitude, with A. flavipes leucogaster ovulating later at high latitudes and A. flavipes flavipes ovulating later in more northerly parts of its range. The combined data and the entirely allopatric distributions of the two subspecies confirm their distinctive status. Bioclimatic analysis suggests further that A. flavipes leucogaster occupies wetter but seasonally more variable environments than its eastern relative. It is clear from the level of morphological, molecular, reproductive and distributional differences that A. flavipes flavipes and A.�flavipes leucogaster should be regarded as separate taxa for the purposes of conservation management, and their current subspecific status should be maintained.

Since 2012, the number of described species in the carnivorous marsupial genus Antechinus has increased by 50%. The present thesis aimed to collect and analyse fundamental ecological data for one newly described species, the black-tailed dusky antechinus, Antechinus arktos, about which virtually nothing was known. Population ecology and geographic range of the species was used to determine conservation status. The foundational ecological information detailed in this thesis concerning breeding biology, diet, activity patterns and optimal detection methods, will assist in planning future conservation initiatives of this endangered marsupial.

Since 2012, five new species of carnivorous marsupial Antechinus have been described. One of these, the threatened silver-headed antechinus (Antechinus argentus), has a highly restricted distribution and occurs in low abundance. When the present study commenced, almost nothing was known of the ecology of the species. Therefore, the aim of this research was to provide foundational knowledge by investigating three main components of the species' ecology: 1. diet, 2. life-history, and 3. habitat use. The aims were achieved and the research resulted in a threatened species listing. The present thesis provides necessary recommendations for ongoing conservation management of the species.

Antechinus is an Australian genus of small carnivorous marsupials. Since 2012, the number of described species in the genus has increased by 50% from ten to fifteen. The systematic relationships of these new species and others in the genus have not been well resolved and a broad phylogeographic study of the genus is lacking. Moreover, little ecological information is known about these new species. Therefore, the present thesis examined the evolutionary biology of Antechinus in two complimentary components. The first component aimed to resolve the systematics and phylogeography of the genus Antechinus. The second component, at a finer spatiotemporal scale, aimed to improve understanding of the autecology, habitat use and risk of extinction within the group, with a focus on the recently named buff-footed antechinus, A. mysticus and a partially sympatric congener, A. subtropicus.

Australia has one of the highest rates of extinction in the world, particularly for mammals of the arid zone. Arid and semi-arid species are subject to a number of threatening processes, including predation from introduced cats (Felis catus) and foxes (Vulpes vulpes), land clearance for agriculture, changing fire regimes post-European settlement and, more recently, increased mining activities and climate change. Unfortunately, the biology, life history and population dynamics of many semi-arid zone mammal species are little known, making effective management and conservation problematic, particularly for those that are considered rare and endangered. One such species is the nationally endangered sandhill dunnart (Sminthopsis psammophila). The species is known from only a small number of individuals inhabiting three disjointed populations; two in South Australia and one in Western Australia. In order to conserve this species, ecological knowledge is required to predict how it is likely to respond to current and future threats, and accordingly what type of management actions are needed to ensure its persistence. This study used a combination of ecological and genetic information from a population in a semi-arid environment to investigate: 1) the influence of a variable environment on the life history and population dynamics of S. psammophila during a high and low rainfall year; 2) broad- and fine-scale genetic diversity and connectivity across the species’ range and within a population and 3) habitat preferences of the species and the influence rainfall and time since fire may have on the habitat preferences. One core population west of the Middleback Ranges on the Eyre Peninsula, South Australia, was trapped for two years during a capture-mark-recapture study comprising 23,529 trap nights. Eleven sites were established within an area of approximately 24,000 ha. The vegetation in the region consists of open mallee with an understorey of spinifex (Triodia spp.) and a diverse range of shrubs. Tissue samples were taken from individuals caught to examine the fine-scale genetic diversity and connectivity within the study area using 16 newly developed microsatellite markers. Additional tissue samples from the remaining two core populations were collected through collaborations to study the historical connectivity across the species’ range using a combination of microsatellite markers and mitochondrial control region sequence data. The broad scale genetic analyses revealed that the three known core populations of S. psammophila are genetically differentiated, but do not show evidence of long-term population isolation. Within the core population the fine-scale genetic analyses and capture-mark-recapture data indicated that both males and females are relatively mobile with no significant genetic structure amongst 107 samples evident within the 24,000 ha study area. In addition, no significant sex-biased dispersal was detected, suggesting it is advantageous for both males and females to disperse from their natal areas. The study found that the presence and abundance of S. psammophila at sites was influenced by rainfall events. During the low rainfall year significantly fewer S. psammophila were caught and a higher proportion of individuals were transients. The changes in the population were attributed to a decreased survival rate of dispersing juveniles and second year adults, most likely caused by reduced food (invertebrates) availability during the low rainfall year. In addition, the breeding season may have been delayed or reduced in response to fewer food resources during that year. S. psammophila was found to be positively associated with the number of logs and vertical habitat complexity and negatively associated with the average height of spinifex (Triodia spp.). These associations likely reflect a preference for areas with increased protection from predators and increased foraging opportunities. We did not detect an effect of time since fire on the presence of S. psammophila. However, resident females were observed favouring sites with slightly higher spinifex density during the low rainfall year. This may suggest a preference for areas that provide increased foraging opportunities in microsites, such as areas where leaf litter accumulates, during low resource years. The relatively high mobility in this species appears to be an adaptation to a system with variable food resources; individuals need to be mobile in order to track food pulses created by rainfall through the landscape. Therefore large areas of suitable habitat will need to be protected in order to maintain a viable S. psammophila population. The preference of S. psammophila for complex understorey suggests that recently burnt vegetation may be unsuitable for the species. Limiting large scale wildfires will be required to protect the species in the future, especially if climate change leads to an increase in the severity and frequencies of wildfires. The findings from this study have been made available to the Sandhill Dunnart Recovery Team and have contributed to the development of an effective conservation management plan for S. psammophila, both regionally and nationally.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Biological Sciences, 2015.

Predators with Pouches provides a unique synthesis of current knowledge of the world’s carnivorous marsupials—from Patagonia to New Guinea and North America to Tasmania. Written by 63 experts in each field, the book covers a comprehensive range of disciplines including evolution and systematics, reproductive biology, physiology, ecology, behaviour and conservation. Predators with Pouches reveals the relationships between the American didelphids and the Australian dasyurids, and explores the role of the marsupial fauna in the mammal community. It introduces the geologically oldest marsupials, from the Americas, and examines the fall from former diversity of the larger marsupial carnivores and their convergent evolution with placental forms. The book covers all aspects of carnivorous marsupials, including interesting features of life history, their unique reproduction, the physiological basis for early senescence in semelparous dasyurids, sex ratio variation and juvenile dispersal. It looks at gradients in nutrition—from omnivory to insectivory to carnivory—as well as distributional ecology, social structure and conservation dilemmas.

Interest in the conservation and welfare of Australian native wildlife continues to grow. Veterinarians are frequently presented with injured, diseased or orphaned animals and there is increasing veterinary involvement in conservation programs. In Australia and overseas, Australian mammals are used in research, kept as pets and are popular display and education animals in zoos and fauna parks. The recognition, diagnosis and treatment of injury and disease in wildlife species present unique challenges for the veterinarian. Radiology is a fundamental diagnostic tool that can be used to further define the nature and extent of injury or disease, guide therapeutic decisions and determine prognosis. An essential aspect of radiology is the recognition and description of abnormal findings. In order to recognise abnormalities, knowledge of normal radioanatomy is necessary. Radiology of Australian Mammals provides a detailed reference on the normal radioanatomy of Australian mammals. A chapter on radiographic technique covers digital radiography of small species, and restraint and positioning to obtain diagnostic images. This is followed by chapters covering the normal radioanatomy of the short-beaked echidna, platypus, macropods, koala, wombats, dasyurids, possums and gliders, bandicoots and the bilby, and bats. Each chapter includes a detailed description of anatomy relevant to radiography and multiple images of normal radiographs with outlines and annotations identifying relevant structures. A chapter on dental radiology discusses and demonstrates normal dental radioanatomy. The final chapter includes selected radiographic pathology case studies providing an appreciation of radiographic findings seen in some common diseases of Australian mammals. A checklist of the mammals of Australia and its territories and a glossary of abbreviations and terms used for annotation of images complete the volume.