University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations 11-7-2015 Vocal and visual communication in an explosively breeding Neotropical toad Nicolas Rehberg-Besler University of Windsor Follow this and additional works at: http://scholar.uwindsor.ca/etd Recommended Citation Rehberg-Besler, Nicolas, "Vocal and visual communication in an explosively breeding Neotropical toad" (2015). Electronic Theses and Dissertations. Paper 5521. This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). Under this license, works must always be attributed to the copyright holder (original author), cannot be used for any commercial purposes, and may not be altered. Any other use would require the permission of the copyright holder. Students may inquire about withdrawing their dissertation and/or thesis from this database. For additional inquiries, please contact the repository administrator via email ([email protected]) or by telephone at 519-253-3000ext. 3208. VOCAL AND VISUAL COMMUNICATION IN AN EXPLOSIVELY BREEDING NEOTROPICAL TOAD By NICOLAS REHBERG-BESLER A Thesis Submitted to the Faculty oF Graduate Studies through Biological Sciences in Partial FulFillment oF the Requirements For the Degree oF Master oF Science at the University oF Windsor Windsor, Ontario, Canada © 2015 Nicolas Rehberg-Besler Vocal and visual communication in an explosively breeding Neotropical toad by Nicolas Rehberg-Besler APPROVED BY: ______________________________________________ K. Drouillard, External Reader Great Lakes Institute oF Environmental Research ______________________________________________ D. Higgs, Internal Reader Biological Sciences ______________________________________________ S. Doucet, Co-Advisor Biological Sciences ______________________________________________ D. Mennill, Co-Advisor Biological Sciences August 7, 2014 Declaration of Co-Authorship I hereby declare that this thesis incorporates material that is the result oF joint research, as Follows: I am the sole author oF chapter 1 and 5, and the principal author oF chapters 2, 3, and 4. Chapters 2, 3, and 4 were conducted under the supervision oF Dan Mennill and Stéphanie Doucet (University oF Windsor)—both oF whom helped guide the development oF the studies, aided in the analyses and writing oF the manuscripts, and provided Financial and logistical support For all Field research. Dan Mennill and Stéphanie Doucet both share authorship on all three data chapters. 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. I certiFy that, with the above qualiFication, this thesis and the research to which it reFers, is the product oF my own work. I certiFy 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. I declare that this is a true copy oF my thesis, including any Final revisions, as approved by my thesis committee and the oFFice oF Graduate Studies, and that this thesis has not been submitted For a higher degree to any other University or Institution. iii Abstract Frogs and toads use both acoustic and visual signals to communicate within their noisy, competitive breeding aggregations. In this thesis, I studied acoustic and visual signals in the Neotropical yellow toad, Incilius luetkenii, in Costa Rica. I provide the First quantitative description oF this species’ vocal behaviour, and I demonstrate that the spectral properties oF male calls are correlated with body size; thereFore, male calls may be used in size assessment. I experimentally demonstrate that chorus transmission distance is enhanced by the number oF concurrently calling toads as well as the pitch oF their calls; thereFore choruses may attract more conspeciFic animals than a lone signaller. In terms oF visual signals, I show that males respond more strongly to Female- like brown models versus male-like yellow models; thereFore colour Facilitates sex recognition. My research expands our understanding oF communication in a scramble competition mating system oF an explosively breeding anuran. iv Acknowledgements First and Foremost, I would like to thank my supervisors, Dan Mennill and Stéphanie Doucet. Both have given me the opportunity to work with incredible systems in an amazing location For three consecutive years. The helpFul guidance provided by my supervisors has truly shaped me as a scientist. I undoubtedly owe much oF my success, present and Future, to the sharp minds and supportive words oF my supervisors. To my committee members, Dennis Higgs and Ken Drouillard, thank you For serving on my supervisory committee and providing insight to help make this the best thesis it could be. To the members oF the Mennill and Doucet Labs, and various others From the Department oF Biological Sciences and GLIER: thank you For sharing this experience with me both in the lab and out. I highly value your Friendship, and I look Forward to keeping in touch with you after grad school. To everyone that helped me collect my data during the extremely short breeding season oF Yellow Toads: without your assistance this thesis would not be possible— thank you. To my parents: thank you For Fostering in me a desire to learn and create, and For always supporting my decisions to pursue higher education. To my brother: thank you For setting the standard For me to Follow. I appreciate the considerable scholarships From the University oF Windsor and the Government oF Ontario, the research grant awarded to me by Sigma Xi, the support provided to me through graduate teaching assistantships in the Department oF v Biological Sciences, and Financial support For my research through grants From the Natural Sciences and Engineering Research Council oF Canada (NSERC), the Canada Foundation For Innovation (CFI), the Government oF Ontario, and the University oF Windsor to Dan and Stéphanie. I thank the stafF oF the Guanacaste Conservation Area (ACG), especially Roger Blanco and the stafF at Sector Poco Sol, For providing logistical support in the Field. Thank you For creating an excellent research environment. vi Table of Contents Declaration oF Co-Authorship ............................................................................................ iii Abstract ............................................................................................................................. iv Acknowledgements ............................................................................................................ v List oF Tables ...................................................................................................................... ix List oF Figures ...................................................................................................................... x Chapter 1 ............................................................................................................................ 1 General Introduction ......................................................................................................... 1 Introduction .................................................................................................................... 2 Acoustic signalling and properties oF sound ................................................................... 2 Chorus dynamics and prolonged breeding ..................................................................... 4 Vocal and visual signals in explosive breeders ............................................................... 5 Study species .................................................................................................................. 7 Thesis goals ..................................................................................................................... 9 ReFerences .................................................................................................................... 11 Figures .......................................................................................................................... 15 Chapter 2 .......................................................................................................................... 16 Vocal behaviour of the explosively breeding Neotropical Yellow Toad ........................ 16 Chapter Summary ......................................................................................................... 17 Introduction .................................................................................................................. 19 Methods ....................................................................................................................... 20 Study Site and Species .............................................................................................. 21 Data Collection ......................................................................................................... 22 Acoustic QuantiFication ...........................................................................................