Geomys Bursarius) Burrow Systems
Total Page:16
File Type:pdf, Size:1020Kb
University of Northern Iowa UNI ScholarWorks Dissertations and Theses @ UNI Student Work 2021 Arthropod fauna of Plains pocket gopher (Geomys bursarius) burrow systems Brett Lyle Gourley University of Northern Iowa Let us know how access to this document benefits ouy Copyright ©2021 Brett Gourley Follow this and additional works at: https://scholarworks.uni.edu/etd Part of the Biology Commons Recommended Citation Gourley, Brett Lyle, "Arthropod fauna of Plains pocket gopher (Geomys bursarius) burrow systems" (2021). Dissertations and Theses @ UNI. 1077. https://scholarworks.uni.edu/etd/1077 This Open Access Thesis is brought to you for free and open access by the Student Work at UNI ScholarWorks. It has been accepted for inclusion in Dissertations and Theses @ UNI by an authorized administrator of UNI ScholarWorks. For more information, please contact [email protected]. Copyright by BRETT GOURLEY 2021 All Rights Reserved ARTHROPOD FAUNA OF PLAINS POCKET GOPHER (GEOMYS BURSARIUS) BURROW SYSTEMS An Abstract of a Thesis Submitted in Partial Fulfillment of the requirements for the Degree Master of Science Brett Lyle Gourley University of Northern Iowa May 2021 ABSTRACT Pocket gophers are among the most asocial mammals, living a solitary existence except for mating and the rearing of offspring. They create expansive burrow systems underground while foraging for food and rarely surfacing above ground. As gophers burrow, excess soil is pushed to the surface or placed in older tunnels. This behavior creates a cave-like ecosystem where pocket gophers and associated arthropods live. Few studies have been done on the arthropod fauna cohabitating with pocket gophers in these burrows. Most of these studies have focused on a family of arthropods over several sites. Many have focused on the southern United States, with few studies done in the Midwest (Minnesota, Nebraska, Wisconsin, Indiana). I examined the arthropods living in Geomys bursarius burrow systems in northeast Iowa. I located a local farm with land in Conservation Reserve Program with a Plains pocket gopher population. There were two prairies with G. bursarius, and samples were taken from burrow systems in both during late July 2015. At each burrow system, I placed a control cup above ground and 3 cups inside the burrow system as a pitfall trap with molasses as bait. In Prairie 1, five G. bursarius burrow systems were sampled, yielding a total of 20 sample cups per day for each of three days. In Prairie 2 three burrow systems were sampled with 12 sample cups per day for three days. In July 2016, more samples were taken from Prairie 1 with a focus on two pocket gopher burrows. The same method was used as the previous year, with samples collected for three days. Through my study, I identified 19 species of macroinvetebrates associated with pocket gopher burrows. An additional eight macroinvertebrates were identified to genus level and nine more were identified to family level. In total, these macroinvertebrates belonged to 24 families, representing a diverse set of cohabitants within the burrows of pocket gophers. Several of the species identified were new local records for Delaware County: Ceuthophilus divergens, Ceuthophilus latens, Anisodactylus ovularis, Harpalus erraticus, Glischrochilus quadrisignatus, Pericompsus ephippiatus, Foxella ignota, Dendrophilus sexstriatus, Geomydoecus geomydus. One species, Stictolinus flavipes, was the first documented in the state. Previously S. flavipes had been identified as far west as Illinois and Wisconsin (Klimaszewski et al. 2005). Twelve species of macroinvertebrates were identified solely within (and not outside) the burrows. While some of these could have entered the opened burrows during the course of this experiment, each of these species may represent specialized burrow inhabitants. ARTHROPOD FAUNA OF PLAINS POCKET GOPHER (GEOMYS BURSARIUS) BURROW SYSTEMS A Thesis Submitted in Partial Fulfillment of the requirements for the Degree Master of Science Brett Lyle Gourley University of Northern Iowa May 2021 ii This Study by: Brett Lyle Gourley Entitled: Arthropod Fauna of Plains Pocket Gopher (Geomys bursarius) Burrow Systems has been approved as meeting the thesis requirement for the Degree of Master of Science ___________ _____________________________________________________ Date Dr. John Ophus, Chair, Thesis Committee ___________ _____________________________________________________ Date Dr. James W. Demastes, Thesis Committee Member ___________ _____________________________________________________ Date Dr. Theresa Spradling, Thesis Committee Member ___________ _____________________________________________________ Date Dr. Jennifer Waldron, Dean, Graduate College iii ACKNOWLEDGEMENTS I would like to thank my advisor Dr. John Ophus and my committee members Dr. James W. Demastes and Dr. Theresa Spradling, for providing support throughout this entire process. I would like to thank Dr. Kenneth Elgersma for his support during this process as well. Also, I want to thank two students who helped me with the preservation and cleaning of specimen: Greg Gustafson and Husein Kurdic. Next, I want to thank my parents, brothers, Monyae Williamson, and friends for encouraging me over the last few years to finish this. Rick and Kerri Linderwell also deserve a thank you for allowing me to conduct this research on their property. Thank you to the University of Northern Iowa Department of Biology and the Graduate College for their financial support. iv TABLE OF CONTENTS PAGE LIST OF TABLES ..................................................................................................................... v LIST OF FIGURES .................................................................................................................. vi CHAPTER 1: INTRODUCTION ................................................................................................1 CHAPTER 2: LITERATURE REVIEW ........................................................................................4 Factors Contributing to Isolation ...................................................................................5 Genetic Effect of Isolation..............................................................................................6 Coevolution ....................................................................................................................7 Arthropods in Pocket Gopher Burrows....................................................................... 10 CHAPTER 3: METHODS ...................................................................................................... 13 Study Site .................................................................................................................... 13 Burrow System Preparation ........................................................................................ 13 Arthropod Collection .................................................................................................. 16 Arthropod Processing and Identification .................................................................... 18 CHAPTER 4: RESULTS......................................................................................................... 19 CHAPTER 5: DISCUSSION ................................................................................................... 25 REFERENCES ...................................................................................................................... 32 APPENDIX .......................................................................................................................... 40 v LIST OF TABLES TABLE PAGE 1. Comparison of parasites identified with pocket gophers........................................9 2. Year 1 pocket gopher mound GPS coordinates .................................................... 16 3. Year 2 pocket gopher mound GPS coordinates .................................................... 16 4. List of identified arthropods collected in control cups and burrow cups year 1 and year 2 ............................................................................................................. 20 5. Total number of specimens, classes, genera, and species found in each burrow system ................................................................................................................... 22 vi LIST OF FIGURES FIGURE PAGE 1. Map of pocket gopher locations year 1, prairie 1 ................................................ 15 2. Map of pocket gopher locations year 1, prairie 2 ................................................ 15 3. Map of pocket gopher locations year 2 ................................................................ 16 4. C. divergens ........................................................................................................... 26 5. C. latens ................................................................................................................. 26 6. H. erraticus ............................................................................................................ 26 7. A. ovularis .............................................................................................................. 26 8. D. sexstriatus ......................................................................................................... 26 9. F. ignota ................................................................................................................ 26 10. G. geomydis ..........................................................................................................