INVESTIGATION OF AN INVASIVE CRAYFISH AND ITS RELATION TO TWO IMPERILED NATIVE CRAYFISHES; ANTHROPOGENIC INFLUENCES, MULTI- SCALE HABITAT ASSOCIATIONS, AND CONSERVATION OPTIONS A Dissertation presented to the Faculty of the Graduate School University of Missouri In Partial Fulfillment Of the Requirements for the Degree Doctor of Philosophy by JACOB THOMAS WESTHOFF Dr. Charles F. Rabeni, Dissertation Supervisor July 2011 The undersigned, appointed by the Dean of the Graduate School, have examined the dissertation entitled: INVESTIGATION OF AN INVASIVE CRAYFISH AND ITS RELATION TO TWO IMPERILED NATIVE CRAYFISHES; ANTHROPOGENIC INFLUENCES, MULTI- SCALE HABITAT ASSOCIATIONS, AND CONSERVATION OPTIONS Presented by Jacob T. Westhoff, A candidate for the degree of Doctor of Philosophy And hereby certify that, in their opinion, it is worthy of acceptance. _________________________________________ Dr. Charles Rabeni _________________________________________ Dr. David Galat _________________________________________ Dr. Scott Sowa _________________________________________ Dr. Raymond Semlitsch _________________________________________ Mr. Robert DiStefano ACKNOWLEDGEMENTS This dissertation was born of the collaboration of many people whom contributed time, money, knowledge, patience, compassion, hard work, and dedication. Numerous people deserve to be acknowledged for their roles in this work that are not specifically mentioned below. To those people, know that despite this omission your contributions were greatly appreciated the dissertation was better for your involvement. I want to begin by thanking my advisor, Dr. Charles Rabeni. Your friendship, guidance, patience, and knowledge far exceed any value I could place on them. I will never forget our initial meeting about this project in which I asked if you would be willing to leave the position vacant until I was able to address my obligations in Tennessee and you responded to the effect of ―for the right person, yes‖. I hope I have proven myself the ―right person‖ for the job and that you have enjoyed our interactions at least fraction of the amount I have. I know the freedom you showed me in developing and conducting the project has enabled me to grow as a scientist beyond what I thought possible. I hope that as the last in a long line of graduate students you have mentored, I was able to give you a pleasant (and not too challenging) transition into retirement. I will forever be grateful to you for all you have done for me. My next expression of gratitude goes to Bob DiStefano. Your involvement in my development as a scientist has far exceeded any level of obligation you had as my boss or as a committee member for this degree. You gave me my first job in the field and have since opened many doors that I may never have even known existed. The way in which you mentor students and employees should impress even the most successful faculty and ii professionals in our field. Thanks for not only all the professional guidance you have given me, but also for your friendship and personal guidance. I feel as though I have learned more from you about science and life in general than any school or class could provide. I also want to thank my committee members; Dr. David Galat, Dr. Raymond Semlitsch, and Dr. Scott Sowa for all of their valuable advice and support. The diverse and vast knowledge that each of you shared with me challenged me on many occasions and both my dissertation and my approach to science have benefited. Thanks to all of the people whom I asked for advice on sampling, study design, analysis, and interpretation. This includes many other graduate students at MU; Cathy Bodinfof, Tom Bonno, Jeff Fore, David Jachowski, Josh Lallaman, and Andy Turner. It also include friends and colleges; Gust Annis, Tyler Black, Doug Novinger, Eric Rahm, Craig Scroggins, and Ivan Vining. This project would not have been possible without the hard working technicians that collected data in sometimes unfavorable conditions. So thank you to Jim Baker, Julian Barnes, Tom Boersig, Adam Kern, Courtney Nicks, and Kara Small. I must also include thanks to the Crayfish Crew members that assisted off and on throughout the project. This project was also made possible by the cooperation of many landowners in the St. Francis River drainage. I often felt as though I was a resident of Iron County and will have fond memories of the people and streams of the area for years to come. Financial support for this work was provided by the Missouri Department of Conservation, the Missouri Cooperative Fisheries and Wildlife Research Unit, and the iii MU School of Natural Resources. The staff of the Missouri Resource Assessment Partnership also contributed much time, data, and advice to this project. I must also thank the faculty and staff at Mizzou. I hope I took full advantage of the wonderful classes and other opportunities presented to me while at Mizzou and I appreciate all of the work that it takes to provide those opportunities. Finally I must thank my friends and family. I had many great conversations over the last four years that helped me to stay focused on my work. Perhaps more valuable though was how those that know me best could tell when I needed a break and helped me to enjoy other aspects of my life. My parents deserve special acknowledgement for all they have done for me over the years. Our many family canoeing and camping trips helped to develop my appreciation of the outdoors and the Ozarks specifically. I hope that my impact on this world will be as positive and substantial as what they have contributed. My last ―thank you‖ goes to my wife, Jolyn. Over the years she has supported me, encouraged me, and helped me realize my potential. Not only did she endure my lengthy absences while I was in the field, but she also sacrificed many things so that I could complete this dissertation and degree. I will forever be grateful and am a lucky person for having her in my life. iv INVESTIGATION OF AN INVASIVE CRAYFISH AND ITS RELATION TO TWO IMPERILED NATIVE CRAYFISHES; ANTHROPOGENIC INFLUENCES, MULTI- SCALE HABITAT ASSOCIATIONS, AND CONSERVATION OPTIONS Jacob T. Westhoff Dr. Charles F. Rabeni, Dissertation Supervisor ABSTRACT Introduced crayfishes often pose a threat to native aquatic biodiversity and the natural function of aquatic systems. In the St. Francis River drainage of Missouri the introduced Woodland Crayfish (Orconectes hylas) has become established and is spreading throughout the drainage. The native crayfish fauna is altered at locations where introduced populations of O. hylas become established and often the imperiled Big Creek Crayfish (Orconectes peruncus) and St. Francis River Crayfish (Orconectes quadruncus) are extirpated from those locations within a few years. The goal of this study was to look for evidence that may explain how O. hylas displaces either of the two natives and provide managers with potential conservation actions to ensure the persistence of native crayfishes. The study objectives were to 1) investigate the association of natural environmental factors and anthropogenic alterations at a coarse- spatial scale with the distributions of O. hylas, O. peruncus, and O. quadruncus, 2) investigate habitat use and selection at a fine-spatial scale for O. hylas and O. quadruncus, and 3) develop a monitoring framework to assess the range expansion of O. hylas and the range contractions of O. peruncus and O. quadruncus. Native crayfishes are often extirpated from portions of their range due to interactions with invasive species, anthropogenic alterations to environmental conditions, v or a combination of these factors. Chapter 2 focused on the objective of identifying coarse-scale natural and anthropogenic factors associated with the current distributions of the invasive O. hylas and two endemic crayfishes (O. peruncus and O. quadruncus) in the St. Francis River drainage and provide insight about the potential role of anthropogenic factors in facilitating species displacement. I used classification trees to model coarse-scale natural and anthropogenic environmental factors and their relation to the presence or absence of each species. Model results were further used to predict probability of presence for each species within each stream segment throughout the St. Francis River drainage. Factors related to geology and soils were the best predictors of species distributions and a dichotomy of these factors explained much of the discrete distributions of the two native species. Agricultural-related factors were identified as the most influential anthropogenic activity related to species distributions. All associations between the invasive species and anthropogenic factors were negative which suggested the invasive was not likely to occur in heavily impacted areas. Overall, models had high correct classification rates and reliably predicted the presence of the invasive in the invaded drainage. Given the negative associations of the invasive with anthropogenic alterations at a coarse spatial scale, I believe that other mechanisms are likely to be responsible for the widespread displacement of the two native species. Chapter 2 focuses on how O. hylas and O. quadruncus use and select habitat at a fine-spatial scale. This approach provides two benefits. First, habitat associations of the two species can be compared to look for similarities or differences that suggest competitive exclusion has occurred. Second, learning about the habitat associations of vi both species can improve our understanding of their ecology and may provide information that can be used to manage the species. These methods also allowed for investigation of the space-use of the two species, movement, growth, and select life- history characteristics. Orconectes peruncus was not included in this portion of the study because of logistical constraints. To achieve the objectives of Chapter 3, individual adult crayfish were tagged with passive integrated transponder tags at locations where O. hylas and O. quadruncus are syntopic and where O. quadruncus are not exposed to O. hylas (allopatric). Crayfish were tracked using a portable antenna during summer, fall, and spring seasons along with diel tracking in the summer.