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Impacts of habitat loss and fragmentation on home range, habitat selection and toxic seed exposure in endangered Carnaby’s cockatoos (Zanda latirostris).
Doctoral Thesis

Impacts of habitat loss and fragmentation on home range, habitat selection and toxic seed exposure in endangered Carnaby’s cockatoos (Zanda latirostris).

Zoe Kissane
Murdoch University
Doctor of Philosophy (PhD), Murdoch University
2025
DOI:
https://doi.org/10.60867/00000085
pdf
Whole Thesis35.55 MB
Embargoed Access, Embargo ends: 07/04/2027

Abstract

Carnaby's black cockatoo--Ecology--Western Australia Carnaby's black cockatoo--Habitat--Western Australia Environmental toxicology--Western Australia
Habitat loss and fragmentation, driven largely by anthropogenic land use changes, are among the most significant drivers of biodiversity decline worldwide. Consequently, Carnaby’s cockatoos (CC) (Zanda latirostris), an endangered species endemic to the southwest of Western Australia, face multiple threats to their survival. This research integrates movement ecology and ecotoxicology to examine how landscape configuration and composition influence spatial ecology of CC, and to develop and trial innovative methods for assessing pesticide exposure risks in wildlife. The first study (Chapter 3) investigated how variation in landscape configuration affects home range size, revealing that fragmentation and loss of native vegetation in agroecosystems increases the home range size of breeding CC. Building on this landscape-scale perspective, the second study (Chapter 4) investigated fine-scale movement by conducting a habitat selection analysis of breeding CC in mixed-use landscapes using GPS data. An integrated step selection analysis (iSSA) approach was used to investigate the effects that vegetation type and edges have on CC foraging and commuting movements. Results confirmed a preference for native vegetation and habitat edges and showed that CC use different movement strategies depending on the surrounding habitat matrix. Step length and turn angle varied significantly depending on whether CC were in native or agricultural habitat, and highlighted the importance of remnant native vegetation in maintaining functional connectivity. Having established how landscape structure influences movement and habitat use, the final study applied these movement insights to assess pesticide exposure risk. The third study (Chapter 5) presents a novel two-step methodology, using GPS telemetry and satellite tracking that firstly identified pesticide exposure sites, then secondly quantified the likelihood and consequences of exposure. A total of 26 pesticides were detected in CC forage sources (agricultural seed), with 80% of seed samples (n=90) having one or more pesticides detected. The Maximum Residue Limit (MRL) in seed samples was exceeded for multiple pesticides including imidacloprid, thiamethoxam, clothianidin, difenoconazole and metalaxyl. Results highlight the risk of chronic exposure to pesticides for granivores and have identified several neurotoxic pesticides that CC are being exposed to that could be contributing to Carnaby’s Hindlimb Paralysis Syndrome (CHiPS). This methodology is broad in scope and applicable across species, providing the ecological realism missing in laboratory-based studies. Collectively, these findings advance our understanding of the spatial ecology of CC and provide a framework for integrating movement data into conservation planning and ecotoxicological risk assessment. The outcomes have direct applications for habitat management, landscape restoration, and mitigation of pesticide-related threats to wildlife.

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UN Sustainable Development Goals (SDGs)

This output has contributed to the advancement of the following goals:

#15 Life on Land

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