University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 2015 FUNCTION AND EVOLUTION OF PLUMAGE TRAITS IN TROGONS (AVES TROGONIFORMES), AND THE IMPORTANCE OF PARAMETERIZATION IN VISUAL MODELS Pierre-Paul Bitton University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Part of the Biology Commons Recommended Citation Bitton, Pierre-Paul, "FUNCTION AND EVOLUTION OF PLUMAGE TRAITS IN TROGONS (AVES TROGONIFORMES), AND THE IMPORTANCE OF PARAMETERIZATION IN VISUAL MODELS" (2015). Electronic Theses and Dissertations. 5714. https://scholar.uwindsor.ca/etd/5714 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. 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FUNCTION AND EVOLUTION OF PLUMAGE TRAITS IN TROGONS (AVES TROGONIFORMES), AND THE IMPORTANCE OF PARAMETERIZATION IN VISUAL MODELS by PIERRE-PAUL BITTON A Dissertation submitted to the Faculty of Graduate Studies through the Department of Biological Sciences in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy at the University of Windsor Windsor, Ontario, Canada © 2015 Pierre-Paul Bitton Function and evolution of plumage traits in Trogons (Aves Trogoniformes), and the importance of parameterization in visual models by Pierre-Paul Bitton APPROVED BY: ______________________________________________ Dr. Robert Montgomerie, External Examiner Department of Biology, Queen’s University ______________________________________________ Dr. Melania Cristescu, External Departmental Reader Department of Biology, McGill University Adjunct to the Great Lakes Institute of Environmental Research, University of Windsor ______________________________________________ Dr. Trevor Pitcher, Internal Departmental Reader Department of Biological Sciences, University of Windsor ______________________________________________ Dr. Daniel Mennill, Internal Departmental Reader Department of Biological Sciences, University of Windsor ______________________________________________ Dr. Stéphanie Doucet, Advisor Department of Biological Sciences, University of Windsor May 15th, 2015 Declaration of Co-Authorship / Previous Publication I. Co-Authorship Declaration I declare that this thesis incorporates material that is the result of joint research, as follows: I am the sole author of the General Introduction, Chapter 1, and the General Discussion, Chapter 6. I am the principal author of the manuscripts that comprise the four data chapters: Chapters 2 through 5. All six data chapters are co-authored with my supervisor, Dr. Stéphanie M. Doucet. Chapter 4 was co-authored by collaborators Drs. Jeffrey DaCosta and John Klicka, and Chapter 5 was co-authored with Kevyn Janisse who also provided the spectral data for the analyses. For all four data chapters, I conceptualized the research projects and experimental designs, and I am primarily responsible for the experimental execution, data analysis, interpretation, and writing. Dr. Stéphanie Doucet contributed to experimental design, interpretation, and the editing of the manuscripts, as well as providing financial and logistical support. My others collaborators provided data, contributed to the analyses, data interpretation, and/or writing and editing of the manuscripts. I am aware of the University of Windsor Senate Policy on Authorship and I certify that I have properly acknowledged the contribution of other researchers to my thesis, and have obtained written permission from my co-authors to include the above material in my thesis. I certify that, with the above qualification, this thesis, and the research to which it refers, is the product of my own work. Chapter 2 is published in Behavioral Ecology, and is formatted for that journal. Chapters 3, 4, and 5 have been formatted for future submission to Journal of Evolutionary Biology, Evolution, and American Naturalist, respectively. iii II. Declaration of Previous Publication This thesis includes one original paper that has been published in a peer reviewed journal, as follows: Thesis Chapter Publication title/full citation Publication status Chapter 2 Published in A multifunctional visual display in elegant trogons Behavioral Ecology targets conspecifics and heterospecifics Chapter 2 is a pre-copyedited, author-produced copy of an article published in Behavioral Ecology following peer review. The version of record “Bitton P-P., and S. M. Doucet. 2014. A multifunctional visual signal in the Elegant trogon Trogon elegans targets conspecifics and heterospecifics. Behavioral Ecology 25: 27-34.” is available online at: http://beheco.oxfordjournals.org/content/25/1/27.short I certify that the above material describes work completed during my registration as graduate student at the University of Windsor. I declare that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, techniques, quotations, or any other material from the work of other people included in my thesis, published or otherwise, are fully acknowledged in accordance with the standard referencing practices. Furthermore, to the extent that I have included copyrighted material that surpasses the bounds of fair dealing within the meaning of the Canada Copyright Act, I certify that I have obtained a written permission from the copyright owner(s) to include such material(s) in my thesis. I declare that this is a true copy of my thesis, including any final revisions, as approved by my thesis committee and the Graduate Studies office, and that this thesis has not been submitted for a higher degree to any other University or Institution. iv Abstract In this dissertation, I investigated the function and evolution of plumage-based visual signals in trogons (Trogoniformes), and assessed the influence of individual parameters in the receptor- noise model of colour discriminability. In Chapter 2, I investigated the function of tail raising in the elegant trogon. For this purpose, I used observational and experimental data collected in Costa Rica. Results demonstrated that tail raising in the elegant trogon is a multifunctional signal that targets both conspecifics and heterospecifics. Specifically, trogons used this behaviour during intra and intersexual interactions, and the experiment confirmed that tail raising is a pursuit-deterrent signal. In Chapter 3, I experimentally tested which plumage patches are used in species recognition in two species of trogons: the black-headed trogon, which is sympatric with a similar-looking congener, and the elegant trogon, which is not sympatric with a similar- looking congener. The results suggested that while both species use the back and belly colour as specie- recognition traits, the black-headed trogon but not the elegant trogon also assessed the tail banding pattern. In Chapter 4, I investigated the relationship between sympatry and plumage divergence in the genus Trogon. My results demonstrated that Trogon taxa diversified more rapidly, and that plumage trait divergence increased with sympatric overlap in South American but not Central American taxa. Together, my findings suggested that the rapid colonization of South America following the Great American Interchange resulted in reinforcement through character displacement or trait sorting. In Chapter 5, I investigated how dichromatism scores are influenced by individual parameters of the receptor-noise model of chromatic contrast threshold, using an avian-based tetrachromatic approach. I systematically tested parameter values for ambient light environment, photoreceptor sensitivities and densities, transmission properties of the ocular media and oil droplets, and compared the v sensory experience of species for which the visual system has been fully characterized. My results demonstrated that oil droplet characteristics, photoreceptor densities, and the sensitivity of the SWS1 photoreceptor (ultraviolet sensitive or not) had the most influence on dichromatism scores. I encourage the complete characterization of visual systems when possible, and my results will inform researchers when making inferences about tetrachromatic visual models. vi Acknowledgements The research presented in this dissertation would not have been possible without the help and support of amazing people. I have met and developed strong relationships with many individuals who will always be remembered. I’d like to thank my supervisor Stéphanie M. Doucet for all her guidance, financial support, comments on manuscripts and grant applications, and giving me a great opportunity to work in the tropics and in museums. Drs. Daniel Mennill, Trevor Pitcher, and Melania Cristescu provided valuable advice throughout my doctoral studies. Much of the data included in this dissertation was obtained