Committee Chair

Wilson, Thomas P.

Committee Member

Aborn, David A.; Carroll, Andrew


Dept. of Biological and Environmental Sciences


College of Arts and Sciences


University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)


In Tennessee, the Barking Treefrog (Hyla gratiosa) is listed as both rare and vulnerable, and more field data is needed to elucidate its distribution. Predictive modeling using the program MaxEnt provided results for models that guided field sampling to potential presence locations. From April-August 2017, 126 sites (63 historical; 63 predicted) were visited monthly and sampled for frog calls according to a standardized protocol. Field results revealed H. gratiosa’s auditory presence at 23 out of 63 historic sites and at nine out of 63 predicted sites. While other predictive models were also generated, MaxEnt was demonstrated to be most precise in predicting presence likelihood. Weighted regression analysis showed that shrub/scrub and woody wetland coverages were the most positively associated with presence. The results suggest that H. gratiosa is not as relatively abundant as some frog species throughout ecologically relevant landscapes in Tennessee.


There are many people I have to thank, for their unwavering, steadfast support, encouragement, and patience throughout the many obstacles of this project. First, I thank Dr. Wilson for all of his sound advising and keeping me grounded, especially when I became overly ambitious on occasions or needed firm guidance. Even more, he has been as supportive and encouraging as a father to me, helping me to feel assured of my abilities and facilitating my growth as a person. He continues to inspire me as a scientist every day and I am deeply honored to have been a member of his lab. Words can only express so much, but I hope he knows how much he has meant to me as an advisor, father-figure, role model and friend. I thank Andy Carroll for believing in my potential and involving me in amazing opportunities in the GIS lab, which seamlessly complimented the skills needed for this project. As my primary workplace supervisor over the past few years, I’ve learned more than just technical skills from him; he reflected all of the ideal qualities of a caring and loyal supervisor, and I am glad to have held him as a role model as well. I’m ever grateful for his support on my committee and for all of the thoughtful advice he’s given. I thank Dr. Aborn for his encouragement and support on my committee, as he has provided insight for this project and words of wisdom for the field sampling. His sense of humor was also welcome and I appreciated his down to earth perspectives. Other professors I must thank are Drs. DeAnna Beasley, Hope Klug, and Jennifer Boyd, for encouraging writing processes and giving thoughtful feedback. Your willingness to guide and assist with the progress of this thesis meant a great deal to me, and the added encouragement along the way helped to cheer me on! I greatly thank Bob English for his contribution and collaboration with data, because it made a large portion of this project possible! Also, I thank Dr. Joanne Romagni, Dr. Ethan Carver, and the Biology/Geology/Environmental Sciences Department for supplying me with funds to carry out the field portion of my project. All of you helped in a great way to help be accomplish my goal! To the friends at the University of the South at Sewanee, I must thank Saunders Drukker, Nate Wilson, Bran Potter, and Dr. Kristen Cecala for their help and support in advising my arrival at certain sites – you all were a great help! While out in the field, I had a select group of individuals that housed me, and so I give a special heartfelt thanks to Jeremy Hooper, Ashley and Nick Tieman, and Susan and Rusty Tuders. All of you were so wonderful to help me out and I will never forget your compassion. Last, but definitely not least, I want to thank all of my family and friends who supported and encouraged me along the way: my parents, my sisters (Ann, Sara, and Elora), my uncles and aunts, Laura Lee, Rebekah Hildebrandt, Joanna Elmore, Brittany Bird, Paul-Erik Bakland, Elijah Reyes, Kelly Daniels, Tori Roy, Charlie Mix and other graduate colleagues, members of Team Salamander and the IGTLab. You all played a role in helping me get to this point in my life, and I am eternally grateful for each of you.


M. S.; A thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Master of Science.




Hylidae -- Tennessee; Frogs; Barking treefrog


Conservation; Amphibian; Barking treefrog; Predictive modeling; Citizen Science; MaxEnt

Document Type

Masters theses




xiii, 78 leaves