Evolutionary signficance of sexual conflict in orb-web spiders. Multiple mating by females creates intense competition between ejaculates over the fertilisation of her eggs, and has a profound influence on male and female life history and mating strategies. In orb-web spiders, sexual cannibalism creates further conflicts of interest because the male may forfeit future matings. This project examines how life-history and mating strategies interact in these spiders, by identifying the mechanisms t ....Evolutionary signficance of sexual conflict in orb-web spiders. Multiple mating by females creates intense competition between ejaculates over the fertilisation of her eggs, and has a profound influence on male and female life history and mating strategies. In orb-web spiders, sexual cannibalism creates further conflicts of interest because the male may forfeit future matings. This project examines how life-history and mating strategies interact in these spiders, by identifying the mechanisms that determine the outcome of sperm competition; the selection pressures favouring sexual size dimorphism and male size variation; the influence of sexual cannibalism on male mating strategies; and the relationship between female feeding history and her mating behaviour.Read moreRead less
Senescence, sociality and sex. As individuals age, their body functions and survival prospects decline. Why some individuals deteriorate slower and later in life, is a critical question we cannot adequately answer, although the social environment has been suggested to be important. Using a recently established molecular biomarker of aging, this project aims to experimentally investigate in a wild bird if age-related decline is faster when individuals lack social support or face sexual competitio ....Senescence, sociality and sex. As individuals age, their body functions and survival prospects decline. Why some individuals deteriorate slower and later in life, is a critical question we cannot adequately answer, although the social environment has been suggested to be important. Using a recently established molecular biomarker of aging, this project aims to experimentally investigate in a wild bird if age-related decline is faster when individuals lack social support or face sexual competition. Expected outcomes are insights into key determinants of delayed aging and longer lifespan. Potential benefits include improved understanding of drivers of healthy aging, and improved ability to predict population persistence and identify conservation priorities. Read moreRead less
Constrained or strategic? Causes and consequences of variation in self-maintenance in wild birds. To live long and healthy lives, animals must defend themselves from diseases and repair damage due to wear and tear. This project will address what prevents animals from achieving optimal defences, and what the consequences are for ageing and survival.
Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of ....Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of larval origin to quantify the degree of self-recruitment and dispersal within/among populations. The results will broaden our understanding of the influence of local (production, habitat) versus regional (dispersal) processes to local population dynamics, information needed for effective stream management.Read moreRead less
Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also ....Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also indicate whether these populations are likely to be closed (i.e., groups of individuals are relatively isolated) along channels or not. We believe our results will show much stream research focuses on the wrong life-stages; practices of river management may need re-assessment.Read moreRead less
Understanding individual differences in social behaviour: the role of personality. This project will investigate how behavioural differences, between individuals, influence key ecological decisions in social animals. The results will shed light on fundamental biological processes, with implications for such diverse applied areas as wildlife management, animal welfare and husbandry, pharmacology, disease risk and job satisfaction.
Are natural clones specialists or generalists? Using a model system to test alternative hypotheses for the advantages of parthenogenesis. Parthenogenetic organisms are all-female and reproduce clonally. Through discovering why these unusual organisms are sometimes successful we can better understand the significance of genetic diversity and sex. The Australian arid zone is a ?hot-spot? for parthenogenesis, with at least five independent examples including a native grasshopper and one of its host ....Are natural clones specialists or generalists? Using a model system to test alternative hypotheses for the advantages of parthenogenesis. Parthenogenetic organisms are all-female and reproduce clonally. Through discovering why these unusual organisms are sometimes successful we can better understand the significance of genetic diversity and sex. The Australian arid zone is a ?hot-spot? for parthenogenesis, with at least five independent examples including a native grasshopper and one of its host plants. I will apply modern molecular tools and ecophysiological techniques to test the hypothesis that parthenogenesis is favoured in this grasshopper because it allows the fixation of locally adapted clones. This research will provide a unique insight into the selective forces operating in the arid zone, Australia's largest ecosystem.Read moreRead less
Social and environmental selection on female ornaments and armaments. Darwin's theory of sexual selection is remarkably successful in explaining how elaborate signals evolved in male animals, but it is unclear whether similar processes drive the evolution of female signals. This project aims to conduct empirical and comparative tests of hypotheses for female trait elaboration, capitalising on inter- and intra-specific variation in female signal form, social organisation and signalling environmen ....Social and environmental selection on female ornaments and armaments. Darwin's theory of sexual selection is remarkably successful in explaining how elaborate signals evolved in male animals, but it is unclear whether similar processes drive the evolution of female signals. This project aims to conduct empirical and comparative tests of hypotheses for female trait elaboration, capitalising on inter- and intra-specific variation in female signal form, social organisation and signalling environments. The project could generate new insight into the processes that promote and constrain phenotypic diversity in nature.Read moreRead less
Community efficiency: testing MacArthur’s minimisation principle for competitive communities. Robert MacArthur, one of the 20th century’s greatest ecologists, developed theory that had profound impacts on our understanding of island biogeography, species coexistence, and competition, yet one of his most powerful theoretical predictions, that competitive communities should become more efficient over time, has never been tested. A greater understanding of the dynamics of community efficiency will ....Community efficiency: testing MacArthur’s minimisation principle for competitive communities. Robert MacArthur, one of the 20th century’s greatest ecologists, developed theory that had profound impacts on our understanding of island biogeography, species coexistence, and competition, yet one of his most powerful theoretical predictions, that competitive communities should become more efficient over time, has never been tested. A greater understanding of the dynamics of community efficiency will provide profound insights into the role of that community in the broader ecosystem, as well as strong predictions about the invasibility and stability of that community. Read moreRead less
Mechanisms of plant species co-existence in species-rich ecosystems: testing hypotheses using spatially-explicit field data and computer models. A generally accepted explanation for the co-existence of species in high diversity communities is one of the outstanding unresolved issues in ecology. Current hypotheses fail to satisfy in their generality; spatial implications are inadequately explored empirically, and the hypotheses are not testable within a common framework. Advances in spatial analy ....Mechanisms of plant species co-existence in species-rich ecosystems: testing hypotheses using spatially-explicit field data and computer models. A generally accepted explanation for the co-existence of species in high diversity communities is one of the outstanding unresolved issues in ecology. Current hypotheses fail to satisfy in their generality; spatial implications are inadequately explored empirically, and the hypotheses are not testable within a common framework. Advances in spatial analysis and complex system modelling now make the search for a general explanation feasible. This project will parameterise and test the different co-existence hypotheses using spatial statistics, empirical/experimental studies of dispersal, recruitment, competition and herbivory, and spatially-explicit computer simulation models of community assemblage in species-rich Australian shrubland communities.Read moreRead less