Abstract
Mining causes significant landscape modification and overlaps with many areas of high biodiversity value. Therefore, some species must persist in mining-disturbed landscapes, likely influencing broader community dynamics and species-specific behaviours, such as movement. One species impacted by mining is the endangered marsupial mesopredator, the northern quoll (Dasyurus hallucatus). The northern quoll exists across northern Australia and has suffered range contractions in all populations except for in the Pilbara region of Western Australia—likely due to the absence of the invasive, poisonous cane toad (Rhinella marina). However, mining is prominent in this region, often targeting the rugged, rocky outcrops that northern quolls rely on for denning and food resources. Rocky habitats are naturally fragmented by wide expanses of spinifex (Triodia spp.) grasslands and riparian habitats, which northern quolls are required to move through to access rocky habitats. The addition of mining alters this habitat structure and likely influences northern quoll movement. Indeed, determining the impacts of mining on northern quoll movement has been listed as a priority for the species. In this thesis, I sought to contextualise mining impacts on animal communities in the Pilbara, build on our understanding of northern quoll movement in undisturbed landscapes, and explore the impacts of mining on fine-scale northern quoll movement and landscape-scale connectivity.
Chapter one provides a brief introduction to the thesis. In chapter two, I
explored the impact of mining infrastructure on fauna species, ecosystem processes, and predator-prey networks in the Pilbara. Mining landscapes facilitated novel species assemblages and reduced mammal richness and the variation of ecological roles. Some species altered their temporal activity in mining landscapes, shifting predator-prey pressures for some animal groups. However, predator-prey networks remained broadly stable, likely due to the resilience of some species to mining.
In chapter three, I investigated the movement of northern quolls in undisturbed landscapes. Northern quolls preferred rugged, rocky habitats and dry riverbeds, and avoided spinifex grasslands relative to the availability of each habitat. Northern quolls had larger home ranges when they used higher proportions of non-preferred spinifex grassland, suggesting that using more unfavourable habitat increased the area needed to obtain resources.
In chapter four, I examined the movement and energy expenditure of northern quolls in a mining landscape. Northern quoll habitat use shifted seasonally: during the breeding season when quolls use more energy, they avoided mining habitats, but in the non-breeding season when quolls use less energy, they used mining habitats similarly to rocky and riparian habitats. Moving through mining habitats increased energy expenditure, likely driving avoidance during the energy-costly breeding season, and potentially affecting breeding dispersal.
In chapter five, I built on the findings of chapter four to simulate northern quoll movement across landscape scenarios with various mining configurations, and without mining, to assess impacts on quoll movement and landscape connectivity. Mining landscapes significantly altered movement corridors and had reduced rocky habitat connectivity compared to the landscape without mining, driven by reduced availability of and longer distances between rocky habitat patches.
Broadly, my findings highlight the complex impacts of mining on wildlife and the need to consider community-level effects when undertaking management in mining landscapes. I have also enhanced our understanding of fine-scale northern quoll movement and habitat selection, particularly in mining landscapes. Mining has negative impacts on northern quoll fine-scale movement and energy expenditure, and is likely to have broader impacts on population-level dispersal and breeding success. The retention and conservation of rocky habitats and existing movement corridors will be important to allow northern quolls to persist efficiently in mining landscapes. Further my findings support the incorporation of animal movement and landscape connectivity into future development planning. Chapter six places my findings in the broader context and discusses some future directions identified in this thesis.
Chapter one provides a brief introduction to the thesis. In chapter two, I
explored the impact of mining infrastructure on fauna species, ecosystem processes, and predator-prey networks in the Pilbara. Mining landscapes facilitated novel species assemblages and reduced mammal richness and the variation of ecological roles. Some species altered their temporal activity in mining landscapes, shifting predator-prey pressures for some animal groups. However, predator-prey networks remained broadly stable, likely due to the resilience of some species to mining.
In chapter three, I investigated the movement of northern quolls in undisturbed landscapes. Northern quolls preferred rugged, rocky habitats and dry riverbeds, and avoided spinifex grasslands relative to the availability of each habitat. Northern quolls had larger home ranges when they used higher proportions of non-preferred spinifex grassland, suggesting that using more unfavourable habitat increased the area needed to obtain resources.
In chapter four, I examined the movement and energy expenditure of northern quolls in a mining landscape. Northern quoll habitat use shifted seasonally: during the breeding season when quolls use more energy, they avoided mining habitats, but in the non-breeding season when quolls use less energy, they used mining habitats similarly to rocky and riparian habitats. Moving through mining habitats increased energy expenditure, likely driving avoidance during the energy-costly breeding season, and potentially affecting breeding dispersal.
In chapter five, I built on the findings of chapter four to simulate northern quoll movement across landscape scenarios with various mining configurations, and without mining, to assess impacts on quoll movement and landscape connectivity. Mining landscapes significantly altered movement corridors and had reduced rocky habitat connectivity compared to the landscape without mining, driven by reduced availability of and longer distances between rocky habitat patches.
Broadly, my findings highlight the complex impacts of mining on wildlife and the need to consider community-level effects when undertaking management in mining landscapes. I have also enhanced our understanding of fine-scale northern quoll movement and habitat selection, particularly in mining landscapes. Mining has negative impacts on northern quoll fine-scale movement and energy expenditure, and is likely to have broader impacts on population-level dispersal and breeding success. The retention and conservation of rocky habitats and existing movement corridors will be important to allow northern quolls to persist efficiently in mining landscapes. Further my findings support the incorporation of animal movement and landscape connectivity into future development planning. Chapter six places my findings in the broader context and discusses some future directions identified in this thesis.
Original language | English |
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Qualification | Doctor of Philosophy |
Awarding Institution |
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Supervisors/Advisors |
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Award date | 25 Oct 2024 |
Place of Publication | Australia |
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Publication status | Published - 2024 |