ABSTRACT HESS, BENJAMIN MATTHEW. Distribution and Taxonomic Status of the Short-Tailed Shrew
Total Page:16
File Type:pdf, Size:1020Kb
ABSTRACT HESS, BENJAMIN MATTHEW. Distribution and Taxonomic Status of the Short-tailed Shrew (Genus Blarina) in North Carolina. (Under the direction of Roger A. Powell). Identifying and describing species is a key component in the study of biology. Species concepts are used to define species based on a specific set of criteria. The phenetic or morphological species concept uses measured characters to create clusters that represent the separation of species or subspecies. The genetic species concept investigates differences in genetic material to separate species or subspecies with a common gene pool. I examined the taxonomic status of the short-tailed shrew (Genus Blarina) in North Carolina using both the morphological and genetic species concepts. Short-tailed shrews have gone through several taxonomic revisions in North Carolina and throughout their ranges in North America. In North Carolina, the northern short-tailed shrew (Blarina brevicauda) with multiple subspecies and the Dismal Swamp short-tailed shrew (B. telmalestes) were recognized in the state. Currently, B. brevicauda knoxjonesi and B. b. talpoides are recognized as the northern short-tailed shrew subspecics, and B. carolinensis carolinensis is recognized as the northern-most subspecies of the southern short-tailed shrew in North Carolina. B. b. talpoides populations are found in the mountains and the northeast part of North Carolina, where these populations are connected with B. b. talpoides populations in Virginia. B. b. knoxjonesi was identified as a disjunct population in the southeast part of North Carolina. Morphological analyses done with the measurements on skulls and mandibles from museum specimens in North Carolina confirmed that B. brevicauda and B. carolinensis are distinct species. B. b. knoxjonesi and B. b. talpoides have substantial overlap in multivariate analyses (principal components analysis, linear discriminant function analysis and classification tree analysis), and exhibit core-edge population size variation in eastern North Carolina based on the classification tree analysis with localities. Genetic analyses done with the cytochrome-b gene extracted from liver tissue from museum specimens also confirm B. brevicauda and B. carolinensis as distinct species. A small samples size (n=1) for B. b. knoxjonesi does not provide substantial evidence for subspecies status, but this sample grouped with all samples of B. b. talpoides in the phylogram created with the cytochrome-b sequence data in Bayesian and maximum likelihood analyses. Both morphological and genetic analyses showed little variation within B. b. carolinensis confirming one subspecies is in North Carolina. My results confirm that two species of the short-tailed shrew (genus Blarina) exist in North Carolina. The subspecies status for the northern short-tailed shrew is questionable based on morphological analyses, but requires more research with genetic analyses. More B. b. knoxjonesi specimens should be analyzed with additional mitochondrial DNA genes sequenced to verify if the status based on genetic analyses is in congruence with the morphological analyses. © Copyright 2016 Benjamin Matthew Hess All Rights Reserved Distribution and Taxonomic Status of the Short-tailed Shrew (Genus Blarina) in North Carolina by Benjamin Matthew Hess A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the Requirements for the Degree of Master of Science ZOOLOGY Raleigh, North Carolina 2016 APPROVED BY: Dr. Jaime A. Collazo Dr. Kevin Gross Minor Representative Dr. Bryan L. Stuart Dr. W. David Webster Dr. Roger A. Powell Chair of Advisory Committee DEDICATION To my family: Jonathan, Georgia, Missy and Tim. This dissertation would not have been possible without all the early times shared in the woods to drive my curiosity. To the late Dr. Gordon L. Kirkland Jr., who took a chance with me and introduced me to museums after my initial field work with Jim Hart – thank you Shippensburg University Vertebrate Museum (“There’s no business like shrew business!”). And to my wife, Shelora, for providing continual love and support during this journey. ii BIOGRAPHY I, Benjamin Matthew Hess, was born and grew up in York, Pennsylvania. I began camping and hiking when I was young, which fostered a great interest in the natural world. While attending Shippensburg University in Pennsylvania, I started my education as a math major with the prospects of becoming a teacher. Knowing that I also wanted to do field work, I ended with a Bachelor of Science (with what is now a designated concentration in Ecology and Environmental Biology) as a major and a minor in mathematics. During this undergraduate work, a summer position as a temporary game farm worker with the Pennsylvania Game Commission led to a position with the Shippensburg University Vertebrate Museum that allowed me the opportunity for extensive field and museum work. I maintained this position until graduation, which sparked a profound interest in the ecology, differences and similarities, and the relationships of mammals. After completion of my undergraduate degree from Shippensburg in 1999, I took non-degree graduate courses and worked various jobs that made me realize that I truly missed biology. I began taking graduate class again in 2004 with the thought of attaining a master’s degree from Shippensburg University. After one year, however, I took on a new job opportunity as the Mammal Collections Manager at the North Carolina State Museum of Natural Sciences in 2005. I started this position with the prospects of continuing my education and after three years, I began my master’s degree at North Carolina State University. Upon graduation with a Master of Science in Zoology, I hope to continue my education with new endeavors. My work and education in North Carolina forged a desire to answer new questions and rekindled my love of teaching. I look forward to my next challenge. iii ACKNOWLEDGEMENTS I would like to first thank my wife Shelora, whose patience and support make this degree more meaningful. Thank you for persevering with me. I thank my committee chair, Dr. Roger Powell, for taking me on as a prospective student and giving me guidance during this degree. I also thank the remainder of my committee, Dr. Jaime Collazo, Dr. Kevin Gross, Dr. Bryan Stuart and Dr. W. David Webster. A special thank you goes to Dr. W. David Webster for the early conversations about shrews and access to the University of North Carolina at Wilmington (UNCW) to begin my work at the mammal collection there. Additional access to the UNCW Mammal Collection was provided by Dr. Brian Chapman, Dr. Sentiel “Butch” Rommel, Amy Cherry Millis and Sarah Hutchinson-Karfas including many late evenings and weekends. Thank you to the “unofficial Powell” lab of Roger Powell, Alana Sullivan, Aimee Rockhill, Scott Robertson, Aaron Facka, Rob Sweirs and others for great conversations during our meetings. Additional work done for specimens and the data associated with the specimens was a group effort at the North Carolina State Museum of Natural Sciences (NCSM – now called the North Carolina Museum of Natural Sciences). Thank you to Lisa Gatens, Bryan McLean, Matt Owen, Bronson Curry, Lydia Fraser, Alexandra Mash, Adrianna Cardinal De Casas, Dawn Keyser, Sam Freeze and others within the Mammal Unit. Early thanks to Jonathan Raine and recent help from M. Ben Norton for GIS mapping of localities at the NCSM. Skull illustrations and layout would not have been possible without the assistance of Liz Bradford and Brenda Wynne. iv Funding for genomics research was made possible by the NCSM Research and Collections Grant 2013-2014. Thank you to Dr. Bryan Stuart for my initial genetics training, and Dr. Julie Horvath and Dr. Julie Urban for allowing me access and use of the NCSM Genomics Lab. I would also like to thank Dr. Heather Farrington, Dr. Olivia Evangelista and Russell Wisser for additional assistance and guidance during my lab work and sequence analysis. Lastly, a special thank you to Dr. Julie Urban for the extra help and trouble-shooting to increase my sample size and final analysis help. v TABLE OF CONTENTS List of Tables ....................................................................................................................... viii List of Figures ...................................................................................................................... x Chapter 1: Introduction: Defining and Designating Species, and the Taxonomic History of the Short-tailed Shrew (Genus Blarina) with an Emphasis on North Carolina ................................................................................................................ 1 Literature Cited .......................................................................................................... 7 Tables and Figures ..................................................................................................... 12 Chapter 2: Morphological Variation in Short-tailed Shrews (Genus Blarina) in North Carolina ............................................................................................................ 15 Abstract ..................................................................................................................... 15 Introduction ............................................................................................................... 16 Materials and Methods .............................................................................................