Boom and bust: the role of fire and rain in driving the dynamics of seeds and rodents in arid Australia. The arid Australian environment oscillates between spectacular boom periods, when biotic productivity and diversity are high, and busts, when biotic resources are depleted. This project first outlines a conceptual model of this dynamic and complex system. It then investigates the roles of rainfall and fire in driving boom-bust events, focusing particularly on food resources (seeds) and their ....Boom and bust: the role of fire and rain in driving the dynamics of seeds and rodents in arid Australia. The arid Australian environment oscillates between spectacular boom periods, when biotic productivity and diversity are high, and busts, when biotic resources are depleted. This project first outlines a conceptual model of this dynamic and complex system. It then investigates the roles of rainfall and fire in driving boom-bust events, focusing particularly on food resources (seeds) and their consumers (desert rodents) in the hyper-variable Simpson Desert. We propose observations and experiments to quantify how these climatic events affect seed production, seed fate, and ultimately the dynamics of desert rodents, and outline their importance for effective management of the desert environment.Read moreRead less
Influence of energy intake on reproduction. Understanding reproduction is fundamentally important to ecology and conservation. Despite intensive research, the processes that regulate energy acquisition and allocation for reproduction are still unclear for most animal species. Many of the obstacles to progress in this field of research are logistical, reflecting the complexity and temporal overlap of significant components of energy allocation pathways. Our proposed study avoids many of these l ....Influence of energy intake on reproduction. Understanding reproduction is fundamentally important to ecology and conservation. Despite intensive research, the processes that regulate energy acquisition and allocation for reproduction are still unclear for most animal species. Many of the obstacles to progress in this field of research are logistical, reflecting the complexity and temporal overlap of significant components of energy allocation pathways. Our proposed study avoids many of these logistical difficulties by focusing on animals (snakes) that display clear temporal partitioning between successive segments of the reproductive cascade (i.e., vitellogenesis, ovulation, embryogenesis); and by adopting a simple but novel method (based on stable isotope analysis) to tease apart the relationship between energy acquisition and energy expenditure in different phases of the animal's life-history.Read moreRead less
Does adaptive plasticity play a significant role in the initial colonisation of novel habitats? An increased understanding of the evolutionary and ecological processes responsible for generating Australian biodiversity can facilitate effective management and conservation of this unique resource. Islands are especially significant in this context because they host many kinds of distinctive fauna and flora that have vanished from mainland habitats. It is therefore crucial to understand the biolo ....Does adaptive plasticity play a significant role in the initial colonisation of novel habitats? An increased understanding of the evolutionary and ecological processes responsible for generating Australian biodiversity can facilitate effective management and conservation of this unique resource. Islands are especially significant in this context because they host many kinds of distinctive fauna and flora that have vanished from mainland habitats. It is therefore crucial to understand the biology of these small isolated systems, as a way to preserve those unique systems as well as the distinctive evolutionary processes that occur within them.Read moreRead less
Why conserve genetic variation? Is this misdirected effort or a crucial concern? In attempting to conserve populations of threatened plants, ecosystem managers must prioritise allocation of resources to both immediate and long-term threats, including loss of genetic variation. This study will determine the importance of maintaining existing genetic variation within populations of several species in a major Australian plant group. As well as advancing theory in the area of plant ecological genet ....Why conserve genetic variation? Is this misdirected effort or a crucial concern? In attempting to conserve populations of threatened plants, ecosystem managers must prioritise allocation of resources to both immediate and long-term threats, including loss of genetic variation. This study will determine the importance of maintaining existing genetic variation within populations of several species in a major Australian plant group. As well as advancing theory in the area of plant ecological genetics and evolutionary biology, our results will provide a stronger scientific basis for the development of conservation policy and management decisions for conserving threatened plant species. Read moreRead less
Facultative sex-determination in a montane lizard. Why is the sex of some reptiles determined by their genetic constitution (sometimes involving heteromorphic sex chromosomes) whereas in other species the animal's sex is determined by the environment (especially, incubation temperature)? Multiple phylogenetic transitions between genetic sex determination (GSD) and environmental sex determination (ESD) suggest that these alternative modes of sex determination possess adaptive significance. Howe ....Facultative sex-determination in a montane lizard. Why is the sex of some reptiles determined by their genetic constitution (sometimes involving heteromorphic sex chromosomes) whereas in other species the animal's sex is determined by the environment (especially, incubation temperature)? Multiple phylogenetic transitions between genetic sex determination (GSD) and environmental sex determination (ESD) suggest that these alternative modes of sex determination possess adaptive significance. However, the selective forces favouring one versus the other remain obscure, despite sustained research in this field by many workers. The recent discovery of BOTH sex-determining systems simultaneously within a single population of alpine lizards provides a unique opportunity to test among competing hypotheses for the evolution of sex-determining systems. I propose an integrated study, in both the field and the laboratory, to clarify the mechanisms and the selective forces involved in the evolution of sex-determination.Read moreRead less
Evolutionary ecology of snakes and lizards. Although reptiles provide excellent "model systems" with which to examine evolutionary and ecological processes, most research in this field has been dominated by studies on other kinds of organisms. I propose a broad-ranging series of studies that will use a diverse array of lizard and snake species to erect and test novel hypotheses on the evolution of phenomena such as mating systems, sexual dimorphism, foraging biology, and reproductive investment ....Evolutionary ecology of snakes and lizards. Although reptiles provide excellent "model systems" with which to examine evolutionary and ecological processes, most research in this field has been dominated by studies on other kinds of organisms. I propose a broad-ranging series of studies that will use a diverse array of lizard and snake species to erect and test novel hypotheses on the evolution of phenomena such as mating systems, sexual dimorphism, foraging biology, and reproductive investment. My experimental studies will clarify the evolutionary role of phenotypic plasticity (that is, direct environmental effects) as well as genetic factors.Read moreRead less
Heterarchical modelling of nutritional ecology: from individuals to communities. The project will combine advances in nutritional theory, agent-based modelling and landscape ecology to produce a modelling framework with which to understand the interrelationships between the physiology and behaviour of individual organisms and the populations, communities and ecosystems in which they reside. The resulting computational model will provide a major new initiative in quantitative ecology and allow sp ....Heterarchical modelling of nutritional ecology: from individuals to communities. The project will combine advances in nutritional theory, agent-based modelling and landscape ecology to produce a modelling framework with which to understand the interrelationships between the physiology and behaviour of individual organisms and the populations, communities and ecosystems in which they reside. The resulting computational model will provide a major new initiative in quantitative ecology and allow specific practical problems to be addressed in relation to agricultural pests, invasive species, conservation biology and animal production systems.Read moreRead less
Fire, bees and other disturbances: the basis for variation in genetic diversity in long-lived plants. An understanding of processes generating temporal and spatial patterns of genetic diversity in perennial plants must underpin successful conservation. Our long-term study will exploit systems in the family Proteaceae in which we have completed foundation studies. We will develop and extend molecular techniques to measure (i) genetic changes from seed to adult, (ii) gene flow by different pollina ....Fire, bees and other disturbances: the basis for variation in genetic diversity in long-lived plants. An understanding of processes generating temporal and spatial patterns of genetic diversity in perennial plants must underpin successful conservation. Our long-term study will exploit systems in the family Proteaceae in which we have completed foundation studies. We will develop and extend molecular techniques to measure (i) genetic changes from seed to adult, (ii) gene flow by different pollinator classes, and (iii) genetic contamination by foreign gene pools, in systems affected by introduced pollinators and natural and cultivar hybridization. Most importantly, we will use fire as an accelerant of generational change and test fitness consequences of changes in genotypic diversity.Read moreRead less
Australian plague locust population genetics and migratory behaviour. The project will allow improved monitoring and forecasting of locusts in Australia and thereby help prevent locust outbreaks. Benefits will arise directly through greater effectiveness in reducing locust damage to crops, and indirectly to Australian rural industry generally through the economic benefits of reduced losses and locust control costs. Environmental and social benefits will also arise from reduced, better targeted u ....Australian plague locust population genetics and migratory behaviour. The project will allow improved monitoring and forecasting of locusts in Australia and thereby help prevent locust outbreaks. Benefits will arise directly through greater effectiveness in reducing locust damage to crops, and indirectly to Australian rural industry generally through the economic benefits of reduced losses and locust control costs. Environmental and social benefits will also arise from reduced, better targeted use of chemical insecticides. This in turn can produce secondary economic benefits, e.g. through enhanced growth and profitability of the organic beef industry within the main locust-outbreak area. Read moreRead less
Ecological and evolutionary impacts of toxic prey. The current invasion of feral cane toads into the Australian wet-dry tropics provides a unique opportunity to study natural selection in action. These highly toxic anurans kill many of the predators that attempt to ingest them. Within two years, the toads will reach a floodplain near Darwin where we are conducting a longterm (already, > 15-year) ecological research program on snakes. The knowledge and data base resulting from this program, pl ....Ecological and evolutionary impacts of toxic prey. The current invasion of feral cane toads into the Australian wet-dry tropics provides a unique opportunity to study natural selection in action. These highly toxic anurans kill many of the predators that attempt to ingest them. Within two years, the toads will reach a floodplain near Darwin where we are conducting a longterm (already, > 15-year) ecological research program on snakes. The knowledge and data base resulting from this program, plus many thousands of individually-marked predators whose home ranges and demographic histories are known, provide a unique opportunity to examine the ecological and evolutionary impact of toads.Read moreRead less