The Value of Animal Behaviour As a Bio-Indicator of Restoration Quality
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Edith Cowan University Research Online Theses: Doctorates and Masters Theses 2018 The value of animal behaviour as a bio-indicator of restoration quality Floyd Holmes Edith Cowan University Follow this and additional works at: https://ro.ecu.edu.au/theses Part of the Ecology and Evolutionary Biology Commons, and the Environmental Sciences Commons Recommended Citation Holmes, F. (2018). The value of animal behaviour as a bio-indicator of restoration quality. https://ro.ecu.edu.au/theses/2106 This Thesis is posted at Research Online. https://ro.ecu.edu.au/theses/2106 Edith Cowan University Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. The University does not authorize you to copy, communicate or otherwise make available electronically to any other person any copyright material contained on this site. 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The value of animal behaviour as a bio-indicator of restoration quality This thesis is presented for the degree of Doctor of Philosophy Floyd Holmes Edith Cowan University School of Science 2018 Copyright Statement I confirm that this electronic version of my thesis does not infringe the copyright of any person or persons. Proof of permission to include material for which I do not hold copyright is attached. AND/OR I have removed 3rd party copyright materials and replaced with a full reference in the online electronic version for material I do not have permission to use online. If I received funds from a third party under a funding agreement or scholarship I confirm that I have not agreed to assign ownership of copyright in my work or any part of it to that third party or otherwise agreed to any other term which might prohibit me from making this work publicly available on ECU Research Online. 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I certify that this thesis does not, to the best of my knowledge and belief: (i) incorporate without acknowledgement any material previously submitted for a degree or diploma in any institution of higher education; (ii) contain any material previously published or written by another person except where due reference is made in the text; or (iii) contain any defamatory material. Student Signature: Date: 10/07/18 ii Abstract Woodland restoration is a complex endeavour, and restoration ecology as a scientific discipline requires constant re-assessments and adjustments if it is to improve outcomes and better provide for biodiversity. The promise of effective restoration is often used to justify destructive processes that affect many of the world’s ecosystems. It is therefore imperative that those promises can be met, which comes down to restoration ecologists’ and land managers’ capacity to predict and facilitate desirable ecological changes in a timely and socio-economically responsible manner. As perspectives have changed, and knowledge has been gained over the past few decades there have been several fundamental shifts in how restoration is done. Efforts to ‘beautify’ degraded areas through the planting of fast growing non-native species is no longer thought of as responsible restoration practice. We have a better understanding of ecological thresholds, the creation of novel ecosystems and the ways ecosystems move between stable states through transitional processes. Yet many restoration projects still fail to deliver positive outcomes for certain taxonomic groups. Fauna are an important component of biodiversity, and yet ecological filters and traps remain common in restored habitats. To date, the focus in restoration has been biased towards restoring flora, while fauna have been under-appreciated and under-utilised. This is likely due to a lack of clarity around how fauna can be used to assess restoration success. This study sought to address that issue by exploring ways fauna could be used to assess habitat quality, and evaluate whether they could fit into existing restoration management tools like a state-and-transition model. Variation in habitat quality was assessed using a number of biodiversity measures and behavioural patterns. This study used Rottnest Island in Western Australia, a mosaic landscape with a woodland restoration program that has been running for over 50 years. The Island’s woodland areas support a resident population of red-capped robins Petroica goodenovii, which was the focal species of this study. The robins are typically ground- foraging insectivores that generally have been found to respond negatively to anthropocentric land use changes. The suitability of the Island’s robin population as an indicator for the larger avian community was assessed to determine whether management and monitoring could simply focus on improving conditions for robins. Unfortunately, robins were found to be a poor indicator of the larger avian community. Factors that were positively correlated with estimated robin iii density, like woodland area and time since last fire, were negatively correlated with density of other avian species of conservation significance. Invertebrate assembly was surveyed as a measure of food resource availability. There was a significant difference between woodland and heathland areas and to a lesser, but still significant, extent between restored woodland areas of different ages and remnant woodland. A major finding of this study was that Coleoptera were scarcely encountered in ground samples outside of remnant patches, but were among the most common orders in arboreal samples, specifically in old restoration. Given that this order is a major component of numerous insectivore diets, it is likely that this difference is influencing foraging habitat quality. This conclusion is supported by difference detected in the birds’ foraging behaviour, as birds in remnants foraged predominantly on the ground, while in restored areas birds were frequently observed collecting prey items from vegetation. Aside from changing their foraging behaviour, the birds were also found to rarely display breeding related behaviours while in restored habitat. This mimicked a significant difference in juvenile robin population density between restored and remnant patches during the breeding season. As such, it appears robins readily use restored areas for feeding resources, but remnants remain a crucial component of their functional habitat requirements, providing important breeding habitat. Behaviour was found to be a useful tool in explaining and verifying measured differences in habitat quality, and in this case, could easily be incorporated into pre-existing fauna monitoring programs. Robins weren’t found to be a suitable indicator species for the bird community, and given the small species pool on the island, management may need to consider all species of conservation significance separately. iv Acknowledgements It was a privilege to have the opportunity to undertake this research. Without the assistance of a number of people and institutions, completion would not have been possible. I especially wish to acknowledge the contributions of my family, who have supported and encouraged me through my academic career. I dedicate this thesis to Arthur Davies, who instilled in me a passion for learning, and taught me to strive for excellence in all aspects of life. Academically, I would like to thank my supervisors Dr Rob Davis and Dr Eddie van Etten for their professional advice and assistance. Their patience and confidence in my abilities have allowed me to develop into a more independent, and capable researcher. While I am sure I was at times a frustrating student who was constantly eager to wander off on tangents, their gentle touch approach allowed me to develop into a more capable researcher. And, I would also like to thank Dr Kayt Davies for providing me with crucial assistance with goal setting and time management. I would like to thank Cassyanna Gray and the other personnel of the Rottnest Island Authority (RIA) for their generous support of this project. The in-kind support, provision of advice, and willingness to help out whenever possible was greatly appreciated. It is my hope that this work is of value to the RIA, and I will gladly assist in future avian related research on the Island. I am equally grateful for Sue Mather and Birdlife Australia’s support of this project. Sue provided valuable insight into the history of avian research on the Island, and Birdlife provided a considerable portion of the financial support for this project.