Edith Cowan University Research Online Theses: Doctorates and Masters Theses 2003 Foraging Ecology And Habitat Selection Of The Western Yellow Robin (Eopsaltria Griseogularis) In A Wandoo Woodland, Western Australia : Conservation Ecology Of A Declining Species Jarrad A. Cousin Edith Cowan University Follow this and additional works at: https://ro.ecu.edu.au/theses Part of the Animal Sciences Commons Recommended Citation Cousin, J. A. (2003). Foraging Ecology And Habitat Selection Of The Western Yellow Robin (Eopsaltria Griseogularis) In A Wandoo Woodland, Western Australia : Conservation Ecology Of A Declining Species. https://ro.ecu.edu.au/theses/1484 This Thesis is posted at Research Online. https://ro.ecu.edu.au/theses/1484 Edith Cowan University Copyright Warning You may print or download ONE copy of this document for the purpose of your own research or study. 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Higher penalties may apply, and higher damages may be awarded, for offences and infringements involving the conversion of material into digital or electronic form. USE OF THESIS The Use of Thesis statement is not included in this version of the thesis. Foraging Ecology and Habitat Selection of the Western Yellow Robin (Eopsaltria griseogularis) in a W andoo Woodland, W estem Australia: Conservation Ecology of a Declining Species. Jarrad A. Cousin BSc (Zoology) (Botany) University of Western Australia February 2003 A thesis submitted in partial fulfilment of the requirements for the degree of Master of Science in Environmental Management. Centre for Ecosystem Management School of Natural Sciences Faculty of Communications, Health and Sciences Edith Cowan University Joondalup WA 6027 EDITH COWAN UNIVERSITY · LIBRARY ABSTRACT This study examined the foraging ecology and habitat selection of the Western Yellow Robin in Wandoo Woodland at Dryandra Woodland, Western Australia. The foraging ecology component was comprised of an examination of foraging behaviour, perch-use selection and pounce-site characteristics. The habitat selection component was comprised of an examination of habitat characteristics of site occupancy and general nesting ecology. The implications of current management at Dryandra Woodland to the ecology of the Western Yellow Robin are discussed in reference to the findings of the present study. Ground-pouncing was the dominant foraging behaviour throughout all seasons, with dead branches of live subcanopy Wandoo trees (Eucalyptus wandoo) and dead fallen timber as the dominant perch substrate throughout all seasons. However, interseasonal shifts were detected, exemplified by a decrease in proportion of ground pouncing, and an increase in foraging height and perching height during the wanner months. These results reflect seasonal changes in foraging behaviour influenced by the seasonality of invertebrate prey abundance, with lower abundance of leaf litter invertebrates and increased abundance of flying invertebrates in wanner months. Intraseasonal shifts in foraging behaviour reflect climatic differences between years. Pounce site characteristics showed selection at multiple spatial scales. At the microhabitat scale, pounce sites had significantly more leaf litter and log material, and Jess bare ground than random points. At the rnacrohabitat scale, the distance ofpo'mce sites to logs was significantly less than expected. Associations between foraging sites and logs represents selection for sites with a greater abundance of invertebrate prey associated with dead fallen timber. This pattern of selection is consistent throughout the year, indicating characteristics of ground pounce foraging locations remain the same year round regardless of the shift in foraging behaviours. The habitat selection component of the study showed that sites occupied by Western Yellow Robins had higher canopy density, higher leaf litter and log density, higher proportions of Wandoo trees and Gastrolobium plants and higher fragment coefficients (indicating occupation of sites away from the woodland/agricultural ecotone). These results reflect selection of variables at multiple spatial scales; namely, selection for sites with abundant invertebrate prey habitat (microhabitat scale), selection Jll for highly productive habitat (macrohabitat scale), and selection for sites with a reduced edge effect (landscape scale). Nest site characteristics showed selection at specific spatial scales. Although nest sites were located at a variety of heights, they were largely associated with the basal crown height of trees, affording them relatively unobstructed views of the ground to spot potentjal predators. Nesting trees were similar in height to sunvunding trees, although nesting trees were almost always shorter than the highest of the surrounding trees. At a macrohabitat scale, habitat surrounding nest sites was no different to habitat at non-ne.;t si_tes, indicating no selection for nest site habitat measured. Territory boundaries varied spatially and temporally, with a contraction of territory boundaries during the breeding season. Nests were normally located with the vicinity of the centre of the breeding territory. The present study indicates the strong association of the Western Yellow Robin with the ground environment, with selection for dense leaf litter and logs at numerous spatial ::-:ales. The current Dryandra Management Plan strategies have the potential to detrimentally alter the ground environment on which the resource requirements of the Western Yellow Robins revolve. The impact of the proposed changes in land tenure of Dryandra Woodland to National Park would result in additional human pressure on the environment. The impact of an influx in weed invasion, introduction of the Phytophthora dieback fungus and vehicle disturbance by an increase in visitors, has the potential to detrimentally alter the ecology of the habitats occupied by Western Yellow Robins. Furthennore, the implementation of the current fire rr.anagement plan and the push for tourism development has the potential to internally fragment Dryandra Woodland to the detriment oft he Western Yellow Robin. Future research ne~ds to examine reasons for the continued decline in the distribution and abundance of the Western Yellow Robin in the wheatbelt. Such research should be undertaken at the landscape scale, by examining the effects of agricultural practices on the ecology of the species, such as the effect of remnant area, habitat loss, habitat fragmentation and isolation, grazing, weed invasion, altered ecosystem processes and inappropriate fire regimes. Research should also be undertaken on the impact of agricultural practices on the ground invertebrates of remnant native vegetation of the wheatl.Jelt, as many of the above effects of agricultural practices has the potential to great!y disturb the ground environment. Such disturbance has the iv potential to alter the abundance of ground invertebrates; an important foraging resource of the Western Yellow Robin. v 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. Signed J arrad A. Cousin 'l\ vi ACKNOWLEDGEMENTS A postgraduate degree is a long and arduous journey. It is a journey that begins with ideas, progresses with tears, and takes many years! It is however a journey that is complemented with an enonnous support crew, without whom the journey could never have progressed. Professor Harry Recher was my supervisor throughout my research. I want to thank him for providing me with the supervision and guidance he has over the length of my research. I also want to thank him for helping me to become more mature over the course of my re)earch, both academically and personally. Apart from assisting me directly in the research, he has also educr:.ted me on public spee.king, presentation skills, and more elementary skills such as grammar and author impact. I also want to thank Harry's secretary, Lynn Barton, for providing a link when Harry was away over east. She was also always a happy character with whom I could talk. Although not one of my supervisors, I would like to express my gratitude to Professor Stephen Davies for his unrelenting support for my study and the development of my career. He provided me with opportunities to band birds in the Murchison, the wheatbelt and on the south coast at Eyre. He also passed on my name to a variety of individuals and organisations whom I subsequently was contracted