Utah State University DigitalCommons@USU All Graduate Theses and Dissertations Graduate Studies 5-2009 Naive Prey versus Nonnative Predators: A Role for Behavior in Endangered Species Conservation Stephanie A. Kraft Utah State University Follow this and additional works at: https://digitalcommons.usu.edu/etd Part of the Biology Commons Recommended Citation Kraft, Stephanie A., "Naive Prey versus Nonnative Predators: A Role for Behavior in Endangered Species Conservation" (2009). All Graduate Theses and Dissertations. 442. https://digitalcommons.usu.edu/etd/442 This Thesis is brought to you for free and open access by the Graduate Studies at DigitalCommons@USU. It has been accepted for inclusion in All Graduate Theses and Dissertations by an authorized administrator of DigitalCommons@USU. For more information, please contact [email protected]. NAIVE PREY VERSUS NONNATIVE PREDATORS: A ROLE FOR BEHAVIOR IN ENDANGERED SPECIES CONSERVATION by Stephanie A. Kraft A thesis submitted in partial fulfillment Of the requirements for the degree of MASTER OF SCIENCE in Ecology Approved: Todd A. Crowl Charles P. Hawkins Major Professor Committee Member Kimberly Sullivan Byron Burnham Committee Member Dean of Graduate Studies UTAH STATE UNIVERSITY Logan, Utah 2009 ii Copyright © Stephanie Kraft 2009 All Rights Reserved iii ABSTRACT Naive Prey Versus Nonnative Predators: A Role for Behavior in Endangered Species Conservation by Stephanie A. Kraft, Master of Science Utah State University, 2009 Major Professor: Dr. Todd A. Crowl Program: Ecology Fish are one of the most imperiled groups of vertebrates worldwide. Threats to fish fall into one of four general categories: physical habitat loss or degradation, chemical pollution, overfishing, and nonnative species introductions. Nonnative predatory fish often have a devastating impact on native prey, especially with endemic fish, whose restricted distribution and often limited evolutionary history with predators make them particularly susceptible to nonnative predators. One reason nonnative fish are often so efficient predators is that the native fish do not recognize the predator as a threat. Although many studies have examined the role of predator odor recognition, no fish have been shown to possess an innate recognition of the odor of predators unless they share a close co-evolutionary history. Many fish learn to identify novel predators through exposure to a predator’s odor in conjunction with a conspecific alarm cue. Alarm cues are substances that are stored in the epidermis of many fish and are released when skin cells are broken. Exposure to novel predator odor in conjunction with alarm cue does not iv necessarily require a fish to survive a close encounter with a predator to be able to learn to recognize the predator. Here I show that it is possible to train hatchery-raised fish (June sucker, Chasmistes liorus) to recognize a nonnative predator odor (largemouth bass, Micropterus salmoides) through exposure to the odor of a predator that has eaten June sucker. I also show that this training can translate into higher survival in subsequent encounters with predators. I propose that training hatchery-raised fish prior to stocking may increase survival of hatchery-raised fish through anti-predator behavior. (77 pages) v ACKNOWLEDGMENTS I would especially like to thank Dr. Todd A. Crowl and my committee members, Drs. Charles P. Hawkins and Kimberly A. Sullivan, for their support and assistance throughout this process. I would also like to thank the Utah Chapter of the American Fisheries Society and Utah State University’s Ecology Center for financial support of my research. I give special thanks to my husband, Erik Archer, without whose support I would never have completed this document. My family and friends have been particularly helpful as well. Specifically, I would like to thank my parents without whose support I would not have the strength to get here. I would also like to thank the members of the Crowl Aquatic Ecology Lab. I am grateful to the staff of the Utah Department of Wildlife’s Fisheries Experiment Station, especially Doug Routledge, for supplying fish and invaluable advice. Stephanie A. Kraft vi CONTENTS Page ABSTRACT.……………………………………………………………………….…. ii ACKNOWLEDGMENTS……….………………………………………………..….. v LIST OF TABLES......................................................................................................... viii LIST OF FIGURES.….................................................................................................. ix INTRODUCTION…………..……………………….................................................... 1 PREVIOUS WORK—LITERATURE REVIEW….………...………………............ 4 STUDY ORGANISM………………………………………….................................... 15 METHODS……….……….………............................................................................... 19 Preparation of Stimuli…………………………………………………………….. 19 Initial trials………………………………………………………………………... 20 Alarm cue experiment...…………………………………………………………... 20 Behavioral measurements…………....…...………………………..…........ 21 Statistical analysis......................................................................................... 22 Learning experiment................................................................................................ 23 Survivorship experiment.......................................................................................... 24 28 RESULTS…………………………............................................................................... Alarm cue experiment……………………………………....……………..........… 28 Learning experiment................................................................................................ 28 DISCUSSION…………………..………………......................................................... 35 LITERATURE CITED.................................................................................................. 42 APPENDICES………………..…………………......................................................... 60 Appendix A. Data from alarm cue experiment........................................................ 61 Appendix B. Data from learning experiment.......................................................... 64 Appendix C. Data from survivorship experiment.................................................... 67 vii LIST OF TABLES Table Page 1 Species shown to respond to damage-released alarm signals……………………...11 2 Native fish of Utah Lake, Utah…………………………………………………….18 3 Nonnative fish established in Utah Lake, Utah…………………………………….19 4 Experimental treatments for experiment one………………………………………26 A.1. Data from alarm cue experiment..………………………………………………….62 B.1. Data from learning experiment.....…………………………………………………66 C.1. Data from survivorship experiment………………………………………………..69 viii LIST OF FIGURES Figure Page 1 Illustration of the behavioral sequence initiated by the release of alarm cues during a predation event…………………...……………………………………..10 2 Experimental design for experiment two ……………………………………….27 3 Time spent dashing (mean + SE) by treatment in the alarm cue experiment……30 4 Time spent freezing (mean + SE) for control and bass treatments in the alarm cue experiment…………………………………………………………………...31 5 Time spent freezing (mean + SE) by exposure history after two and ten days in the learning experiment………………………...……………………………..32 6 The number of trials with and without predation for both trained and naïve fish………………………………………………………………………...33 7 Distribution of sucker consumed in survivorship experiment experiment trials…………………..………………………………………………………….34 INTRODUCTION The loss of native species is a subject of concern for conservationists and managers worldwide. Fish represent one of the most specios vertebrate groups on the planet (Helfman et al. 1997). Over the last few decades the number of threatened and endangered fish has increased dramatically. The number of fish listed as threatened, endangered or extinct on the International Union for the Conservation of Nature’s (IUCN) Red List has gone from 734 in 1996 to 1275 in 2008. Some estimates suggest 35% of fish native to North America are threatened (Helfman 2007). Of 377 vertebrate species and subspecies on the United States Endangered Species List, 138 are fish (U.S. Fish and Wildlife Service 2008). Freshwater fish are particularly threatened (Bruton 1995). In North America alone, there have been at least 42 documented extinctions of freshwater fish species and subspecies (Dextrase & Mandrak 2006). The decline of freshwater fish can be linked to four general threats: physical habitat degradation and alteration, chemical pollution, overexploitation, and nonnative species introductions (Warren & Burr 1994; Bruton 1995). Nonnative species can affect native fish in many ways, including habitat alteration, competition, introduction of disease, hybridization, and predation (Dextrase & Mandrak 2006). Predation is often the most harmful effect of nonnative fish. Often when nonnative predatory fish become established in freshwater systems, the result is rapid population decline in native fish, sometimes leading to local extinction (McIntosh et al. 1994; Lodge et al. 1998; Mills et al. 2004). The negative effects of nonnative species can be exaggerated in freshwater systems due to isolation and lack of refuge for native species. Nonnative predators are particularly 2 effective in reducing populations of endemic fish (Bruton 1995). Freshwater fish exhibit high levels of endemism due to the difficulty of dispersion within and between watersheds. The isolation that facilitated the evolution of endemic species