An Evaluation of Coyote Diets on the Rolling Plains Quail Research Ranch, Texas, across La Niña versus El Niño Weather Patterns by Cade B. Bowlin, B.S. A Thesis In Wildlife, Aquatic and Wildlands Science and Management Submitted to the Graduate Faculty of Texas Tech University in Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCES Approved Philip S. Gipson, Ph.D. Chair of Committee Dale Rollins, Ph.D. John Baccus, Ph.D. Mark Sheridan, Ph.D. Dean of the Graduate School December, 2018 ©2018, Cade B. Bowlin Texas Tech University, Cade B. Bowlin, December 2018 ACKNOWLEDGEMENTS This research could not have come to fruition without the Rolling Plains Quail Research Foundation and the Rolling Plains Quail Research Ranch. I thank my committee members Philip S. Gipson PhD, John Baccus PhD, Dale Rollins PhD, and the Department of Natural Resources Management at Texas Tech University. I would like to additionally thank Mark A. Tyson for his previous work on coyote diets on the Rolling Plains Quail Research Ranch. I also thank Lloyd M. Lacoste for his friendship, encouragement, and assistance in a multitude of capacities during this project. Mr. Lacoste was an integral part of the successful completion of this research project. Additionally I thank the many technicians of the Rolling Plains Quail Research Ranch that contributed to this project. Bradley W. Kubecka compiled and synthesized much of the supporting data from the Rolling Plains Quail Research Ranch. I also recognize Mr. Kubecka for his dedication and contributions, not only to this project but also to the research ranch, the foundation, and its countless associates. I thank the Texas Tech Natural Science Research Laboratory for loan of guard hair samples used for species identification. I would also like to thank Hong Seomun and Meghan Mahurin for their assistance in the laboratory. I would be remiss if I didn’t thank J.L.M. Knudsen, the finest naturalist I know, and also Neil Estes, Sean Yancey, and James Morel for their friendships during my time at Texas Tech. Most importantly I would like to thank Rigby, Brutas, and Bailey. It was their courage, resilience, and tireless pursuit that financed my graduate degree. For that I am humbled and forever grateful. As Gene Hill said, “Without them I would have been empty. They have made my life full.” ii Texas Tech University, Cade B. Bowlin, December 2018 TABLE OF CONTENTS ACKNOWLEDGMENTS .............................................................................................ii ABSTRACT ..................................................................................................................iv LIST OF TABLES .....................................................................................................…v LIST OF FIGURES ......................................................................................................vi CHAPTER I. INTRODUCTION ..............................................................................…1 Literature Cited ................................................................................................14 CHAPTER II. DIETS OF COYOTES ON THE ROLLING PLAINS QUAIL RESEARCH RANCH, TEXAS, DURING AN EL NIÑO WEATHER PATTERN ...............................................................................................23 Introduction ......................................................................................................23 Study Area .......................................................................................................25 Methods............................................................................................................32 Results ..............................................................................................................36 Discussion ........................................................................................................53 Management Implications ................................................................................64 Literature Cited ................................................................................................65 CHAPTER III. LONGITUDINAL EVALUATION OF COYOTE DIETS DURING EL NIÑO v LA NIÑA WEATHER PATTERNS .......................................73 Introduction ......................................................................................................73 Study Area .......................................................................................................77 Methods............................................................................................................82 Results ..............................................................................................................86 Discussion ......................................................................................................102 Management Implications ..............................................................................111 Literature Cited ..............................................................................................113 iii Texas Tech University, Cade B. Bowlin, December 2018 ABSTRACT The objective of this study was to evaluate coyote diets on a landscape dedicated exclusively to maximizing production of northern bobwhite (Colinus virginianus) and assess whether coyotes (Canis latrans) are important predators of bobwhites and their nests during El Niño versus La Niña weather cycles. Coyote scats were collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas during a La Niña weather pattern (n=356 scats, 2011) and also during an El Niño weather pattern (n=480 scats, 2015-2017). Abundance of bobwhites varied greatly between the 2 study periods (0.13 bobwhites/ha in 2011 vs. 2.3 bobwhites/ha in 2016). No quail remains or remnants of eggshells were identified in coyote scats collected during the La Niña period. Only 3 scats (<1%) collected during the El Niño period contained quail vestiges and 14 scats (2.9%) contained eggshells. Mast (e.g., Opuntia, Prosopis) was especially important during La Niña, but not El Niño diets. Diets of coyotes during the 2016 period were dominated by cotton rats (Sigmodon hispidus). I conclude that coyotes were not important predators of quail or quail nests on a landscape managed exclusively for quail production. iv Texas Tech University, Cade B. Bowlin, December 2018 LIST OF TABLES Table 2.1 Abundance of coyotes and various species of prey observed during helicopter surveys flown on the Rolling Plains Quail Research Ranch, Fisher County, Texas 2015-2017. .............................................................43 Table 2.2 Frequency of occurrence (freq. occ) and percent occurrence (pct. occ) of all individual food items recovered from coyote scats (n=480) collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, November 2015-February 2017. ......................................44 Table 2.3 Frequency of occurrence (freq. occ) and percent occurrence (pct. occ) of major food categories recovered from coyote scats (n=480) collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, November 2015-February 2017. ....................................................46 Table 2.4 Seasonal percent occurrence of major prey categories recovered from coyote scats (n=480) collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, during 2015-17. .........................47 Table 3.1. Percent occurrence of all individual food items recovered from coyote scats (n=356) collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, January 2011-December 2011 (Tyson 2012). .........................................................................................................94 Table 3.2. Percent of coyote scats containing prey categories collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, during a La Niña weather pattern (2011, n=356) (Tyson 2012). ..........................95 Table 3.3. Percent occurrence of all individual food items recovered from coyote scats (n=360) collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, January 2016-December 2016. .................97 Table 3.4. Percent of coyote scats containing prey categories collected monthly on the Rolling Plains Quail Research Ranch, Fisher County, Texas, during a El Niño weather pattern (2016, n=360). .................................................97 Table 3.5. Percent occurrence of rodents recovered from coyote scats collected on the Rolling Plains Quail Research Ranch, Fisher County, Texas, during La Niña (2011, n=356) and El Niño (2016, n=360) weather patterns. .....................................................................................................98 Table 3.6. Percent occurrence of mast recovered from coyote scats collected on the Rolling Plains Quail Research Ranch, Fisher County, Texas, during La Niña (2011, n=356) and El Niño (2016, n=360) weather patterns. .....................................................................................................99 v Texas Tech University, Cade B. Bowlin, December 2018 LIST OF FIGURES Figure 2.1. Map illustrating the 10 ecoregions in Texas with the Rolling Plains ecoregion shaded. The Rolling Plains Quail Research Ranch (RPQRR), Fisher County, Texas is indicated by the red dot..................27 Figure 2.2. Map of the Rolling Plains Quail Research Ranch with state of Texas inset, Fisher County highlighted