Theses and Dissertations at Montana State University (MSU)
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Item Investigating the role of dispersal on the genetic structure of wild populations(Montana State University - Bozeman, College of Letters & Science, 2014) Powell, John Henry, III; Chairperson, Graduate Committee: Steven Kalinowski; Steven T. Kalinowski, Mark L. Taper, Jay J. Rotella, and R. A. Garrott were co-authors of the article, 'Estimating inbreeding depression in a non-pedigreed population of Weddell seals Leptonychotes weddellii' submitted to the journal 'Evolution' which is contained within this thesis.; Steven T. Kalinowski, Megan D. Higgs, Michael R. Ebinger, Ninh V. Vu, and Paul C. Cross were co-authors of the article, 'Microsatellites indicate minimal barriers to mule deer Odocoileus hemionus dispersal across Montana, USA' in the journal 'Wildlife biology' which is contained within this thesis.; Steven T. Kalinowski, Megan D. Higgs, and Clint C. Muhlfeld were co-authors of the article, 'Hybridization did not appear to increase dispersal in a westslope cutthroat trout Oncorhynchus clarkii lewisi metapopulation' submitted to the journal 'Canadian journal of fisheries and aquatic sciences' which is contained within this thesis.The movement of individuals among populations (dispersal) is an ecological process that can affect the genes of populations. Identifying the role this process plays in the wild can be difficult due to uncertainty caused by other genetic and ecological processes. Here, I present three studies investigating the role of dispersal in wild populations of Weddell seals (Leptonychotes weddellii), mule deer (Odocoileus hemionus) and westslope cutthroat trout (Oncorhynchus clarkii lewisi). Each of these studies presents, to my knowledge, novel statistical approaches within this discipline that account for the uncertainty caused by other genetic and ecological processes when investigating the role of dispersal. In the second chapter I present a study that uses a two-step maximum likelihood analysis, fit with the data cloning algorithm, to incorporate uncertainty in estimating the probability that an individual has multiple copies of the same gene from a given ancestor into estimates of the association between this probability and the number of pups a female Weddell seal will produce in her life. This study did not find strong support for the hypothesis that increased similarity of an individual's genes reduced the number of pups she would produce across her lifetime. In the third chapter I use individual based genetic distance measures to investigate the association between features of the landscape and the genetic similarity of mule deer. This study found no detectable barriers to dispersal of mule deer across Montana. The fourth chapter presents a study comparing the dispersal rate between samples of westslope cutthroat trout from Glacier National Park that have interbred with introduced rainbow trout (Oncorhynchus mykiss) to samples that have not. There was no detectable difference in the dispersal rate of westslope cutthroat trout that have interbred with introduced rainbow trout relative to those that have not. In conclusion, dispersal is an important ecological process affecting the genes of populations, but understanding the role it plays across a landscape requires adequately accounting for the uncertainty due to other genetic and ecological processes. The three studies presented highlight different ways of addressing this problem when investigating the role of dispersal in the wild.Item Thermal adaptation of westslope cutthroat trout Oncorhynchus clarkii lewisi(Montana State University - Bozeman, College of Letters & Science, 2010) Drinan, Daniel P.; Chairperson, Graduate Committee: Alexander V. Zale; Molly A. H. Webb (co-chair)Understanding local adaptations is a fundamental goal of evolutionary biology and would provide managers information necessary to better protect and conserve species. Salmonids are a particularly useful system for studying local adaptations as they often persist in disparate and isolated environments. In addition, their sensitivity to temperature provides a likely candidate for natural selection to act. I studied thermal adaptation in four wild populations and one hatchery stock of westslope cutthroat trout. Native stream mean summer temperatures ranged from 6.7° to 11.2°C. Embryos were collected from the wild and differences in embryonic development, embryonic survival, and juvenile growth were measured. I found a significant relationship between median embryonic survival and native stream temperatures at warm incubation temperatures (Rank test; P = 0.04). The change in embryonic survival across incubation temperatures was consistent for populations from warm streams, but changed drastically for populations from cool streams. This difference suggests that populations from warmer streams may be thermal generalists, and populations from cooler streams may be thermal specialists. Results have both short- and long-term implications. In the short-term, managers should use these data to support the consideration of local adaptations when performing translocation projects. In the long-term, these data suggest that global climate change may be detrimental for westslope cutthroat trout.Item Entrainment losses of westslope cutthroat trout into screened and unscreened irrigation canals on Skalkaho Creek, Montana(Montana State University - Bozeman, College of Letters & Science, 2005) Gale, Steven Burton; Chairperson, Graduate Committee: Alexander V. ZaleIrrigation canals are known to entrain anadromous and potamodromous salmonids of all life stages during their annual migrations. Fish screens may reduce or eliminate entrainment, but few studies exist on their benefits and these have evaluated effects on anadromous populations only. Prior to my study, none existed on the benefits of fish screens for non-anadromous salmonids. Large numbers of post-spawn adult and downstream migrant juvenile westslope cutthroat trout (Oncorhynchus clarkii lewisi) are potentially entrained into the seven irrigation canals on Skalkaho Creek, a tributary of the Bitterroot River. I quantified entrainment rates into the canals using telemetry and trapping before (2003) and after (2004) installation of three fish screens. I also examined the efficacy of the screens in returning downstream migrants to the stream. No telemetered adults were entrained in 2003, but most were residents and therefore did not migrate past the canals. In 2004, 79% of the telemetered adult migratory fish were entrained at either screened or unscreened canals, but all adults entrained in screened canals were successfully bypassed back to Skalkaho Creek. Only eight of 117 telemetered age-1 juveniles were entrained, whereas the others were residents and did not migrate. Only one of three age-1 juveniles entrained in 2004 was bypassed. The low number of migratory adult fish and age-1 juveniles I was able to telemeter suggests that the non-migratory, resident life history is now being selected for in this system, but screens should reverse this process. Downstream movement of age-0 westslope cutthroat trout in Skalkaho Creek increased their risk of entrainment. The Highline Canal entrained about 71% of age-0 westslope cutthroat trout moving downstream in 2003. If not for the screen to bypass them in 2004, 38% would have been entrained in the Highline Canal. A total of 6,049 age-0 westslope cutthroat trout were bypassed by all three screens. Most age-0 westslope cutthroat trout entrained at screened canals were successfully bypassed, whereas those entrained at unscreened canals were lost to the population. Fish screens were an effective management tool to reduce or eliminate entrainment at Skalkaho Creek and may be useful elsewhere to eliminate entrainment of inland salmonids.Item Effects of temperature on survival and growth of westslope cutthroat trout and rainbow trout : implications for conservation and restoration(Montana State University - Bozeman, College of Letters & Science, 2005) Bear, Elizabeth Ann; Chairperson, Graduate Committee: Thomas E. McMahonWestslope cutthroat trout Oncorhynchus clarkii lewisi have declined throughout their native range in the Northern Rockies and were considered for listing under the federal Endangered Species Act. Water temperature is widely regarded as playing a key role in determining their persistence, but specific lethal levels and thermal optima for this cutthroat trout subspecies had not been precisely defined. This laboratory study used the acclimated chronic exposure method to determine tolerances and thermal optima of westslope cutthroat trout and rainbow trout Oncorhynchus mykiss, a potential nonnative competitor now occupying much of the former range of westslope cutthroat trout. Rainbow trout had a distinct survival advantage over westslope cutthroat trout at warmer temperatures. The ultimate upper incipient lethal temperature (temperature at which 50% of the population survives for 60-d) of rainbow trout (24.3°C; 95% CI, 24.0 - 24.7°C) was 4.7°C higher than that of westslope cutthroat trout (19.6°C; 95% CI, 19.1 - 19.9°C). In contrast, the optimum growth temperature for westslope cutthroat trout (13.6°C; 95% CI, 10.3 - 17.0°C) over the 60-d test period was very similar to that of rainbow trout (13.1°C; 95% CI, 6.8 - 18.2°C), although rainbow trout grew better over a wider range and at higher temperatures than did westslope cutthroat trout. The upper lethal and optimum growth temperatures for westslope cutthroat trout are in the lower range among most salmonids. The higher upper temperature tolerance of rainbow trout and its greater ability for growth at warmer temperatures may account for its increased occurrence at lower elevations than cutthroat trout. Water quality standards setting maximum daily temperatures from 13-15°C, near the optimum growth temperature, would ensure suitable thermal habitat to maintain the persistence of westslope cutthroat trout populations. In addition, survival and growth parameters indicated in this study can be used with stream temperature modeling to predict suitable habitat for westslope cutthroat trout, as they may be particularly susceptible to increases in stream temperature associated with climate change. Such predictions of habitat suitability will be vital in prioritizing conservation efforts with respect to reintroduction and translocation of westslope cutthroat trout.Item Natural selection in the field and the classroom(Montana State University - Bozeman, College of Letters & Science, 2012) Andrews, Tessa Marie; Chairperson, Graduate Committee: Steven Kalinowski; Bradley B. Shepard, Andrea R. Litt, Carter G. Kruse, Lee M. Nelson, Patrick Clancey, Alexander V. Zale, Mark L Taper, and Steven T. Kalinowski were co-authors of the article, 'Performance of cutthroat trout from five populations translocated as embryos into a fishless common habitat in Montana' in the journal 'Canadian journal of fisheries and aquatic sciences' which is contained within this thesis.; Bradley B. Shepard, Andrea R. Litt, Carter G. Kruse, Alexander V. Zale, and Steven T. Kalinowski were co-authors of the article, 'Juvenile dispersal among cutthroat trout introduced as embryos to vacant habitat' in the journal 'North American journal of fisheries management' which is contained within this thesis.; Mary J. Leonard, Clinton A. Colgrove, and Steven T. Kalinowski were co-authors of the article, 'Active learning not associated with student learning in a random sample of college biology courses' in the journal 'Cell biology education-life sciences education' which is contained within this thesis.; Steven T. Kalinowski and Mary J. Leonard were co-authors of the article, 'Are humans evolving? : a classroom discussion to change student misconceptions regarding natural selection' in the journal 'Evolution education and outreach' which is contained within this thesis.This dissertation examined natural selection in westslope cutthroat trout (Oncorhynchus clarkii lewisi) and undergraduate learning in the subject area natural selection. Translocation-moving individuals to a new habitat to establish, re-establish or supplement a population-is a crucial management strategy for cutthroat trout. One of the major questions managers face in a translocation is which population(s) should contribute individuals? Unfortunately, we often know little about the differences among potential contributing population. The goal of the first half of this dissertation was to look for differences in performance among individuals from five populations of westslope cutthroat trout. I assessed survival, growth, and condition (Chapter 2) and dispersal (Chapter 3) following the translocation of embryos from these five populations to six introduction sites in Cherry Creek. No differences existed among these populations in relative survival, growth, or condition at age 1 or 2. In contrast, statistically significant differences existed in dispersal distance among these populations. These differences were consistent across some, but not all, introduction locations. As our knowledge of evolutionary biology has continued to grow, so too has our knowledge of how students learn evolution. Students taught using active learning strategies can learn substantially more about complex scientific concepts than students taught using primarily lectures. The goal of the second half of this dissertation was to further examine how students learn natural selection and how instructors facilitate that learning. I conducted a national survey of the relationship between an instructor's use of active learning strategies and how much students learned about natural selection (Chapter 4). I used a random sample of instructors from the largest and most prestigious universities in the country so that my results could be inferred to this large population of instructors. The degree to which instructors used active learning was NOT associated with student learning in this population of typical biology instructors. However, I found that a discussion of contemporary human evolution that used active learning strategies could effectively facilitate student learning of natural selection (Chapter 5).Item An assessment of losses of native fish to irrigation diversions on selected tributaries of the Bitterroot River, Montana(Montana State University - Bozeman, College of Letters & Science, 2007) Bahn, Leslie; Chairperson, Graduate Committee: Alexander V. ZaleWithdrawals of surface water for irrigation and stock water leave the Bitterroot River and its tributaries chronically dewatered during the irrigation season. These water withdrawals affect local trout populations by entraining migratory trout into irrigation diversion canals at multiple life stages, and through the loss and degradation of available habitat for aquatic species. Irrigation losses may be responsible in part for the low abundances and restricted distributions of migratory native westslope cutthroat trout Onchorhyncus clarkii lewisi and bull trout Salvelinus confluentus in this system. My objectives were to quantify entrainment of fish into irrigation diversions on Lost Horse and Tin Cup Creeks, two tributaries of the Bitterroot River used by migratory adult westslope cutthroat trout for spawning, and to identify characteristics of these diversions that correlate with entrainment. I sampled fish species by snorkeling, electrofishing, fry trapping, and reconnaissance at 60 sites in 2005 and 54 sites in 2006. Annual entrainment estimates for age-0 salmonids were 18,061 and 8,972 in 2005 and 2006 in Lost Horse Creek diversions. Concurrent entrainment estimates for Tin Cup Creek were 2,995 and 2,312. Annual entrainment estimates for juvenile and adult trout (>40 mm TL) were 7,947 and 7,877 in 2005 and 2006 in Lost Horse Creek diversions.Item Fish screen efficiency and effects of screened and unscreened irrigation canals on the downstream movement of westslope cutthroat trout juveniles in Skalkaho Creek, Montana(Montana State University - Bozeman, College of Letters & Science, 2007) Harnish, Ryan Alexander; Chairperson, Graduate Committee: Alexander V. ZaleFish screens were installed in three of seven irrigation canals that divert water from Skalkaho Creek, a tributary of the Bitterroot River, in 2003 to prevent the loss of fluvial-adfluvial westslope cutthroat trout to irrigation canal entrainment. A study conducted in 2003 and 2004 established that fish screens were effective at reducing the loss of adult and age-0 westslope cutthroat trout. The efficiency of fish screens at preventing the loss of age 1-4 juveniles, the effect of screening on age-0 westslope cutthroat trout downstream movements, and the magnitude of entrainment at unscreened canals remained unclear after this initial study. The goal of my study was to address these information gaps. Fish screens prevented the loss of about 82% of entrained juvenile westslope cutthroat trout and bull trout. About 69% of entrained juveniles exited the screened canals through the headgates, 14% were bypassed, 12% remained in the canals, and the fate of 5% remained unknown. Entrained fish took about 7 days to exit the screened canals. Fish screen efficiency, the route used by fish to exit, and the amount of time taken by fish to exit varied by canal.Item Behavioral, ecological, and fitness consequences of hybridization between native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and nonnative rainbow trout (O. mykiss)(Montana State University - Bozeman, College of Letters & Science, 2008) Muhlfeld, Clint Cain; Chairperson, Graduate Committee: Thomas E. McMahonAnthropogenic hybridization is one of the greatest threats to global biodiversity. Hybridization and introgression may lead to a loss of locally adapted gene complexes and ecological adaptations in native populations, yet these potential consequences have not been fully evaluated in nature. I investigated factors influencing the spread of hybridization between native westslope cutthroat trout (Oncorhynchus clarkii lewisi) and nonnative rainbow trout (O. mykiss) in the upper Flathead River system, Montana (USA) and British Columbia (Canada). The fundamental questions of my dissertation were: what are the behavioral, ecological, and fitness consequences of hybridization and what factors influence successful invasion of hybrids? First, I assessed the patterns of spawning between parental species and their hybrids and found that hybridization alters the spawning behavior of migratory westslope cutthroat trout, and is spreading via long distance dispersal of hybrids from downstream sources and some temporal overlap during spawning. Second, I describe for the first time how a wide range of levels of nonnative admixture affect fitness of cutthroat trout in the wild by estimating reproductive success in a recently invaded stream using parentage analysis with multilocus microsatellite markers. Small amounts of hybridization markedly reduced reproductive success, with fitness exponentially declining by ~50% with 20% nonnative genetic admixture. Finally, I evaluated the association of local-habitat features, landscape characteristics, and biotic factors with the spread of hybridization in the system, and found that hybridization increases in streams with warmer water temperatures, high land use disturbance and close proximity to the source of hybridization; however, none of these factors appeared sufficient to prevent further spread. These combined results suggest that hybrids are not only genetically different than westslope cutthroat trout but also have reduced fitness and are ecologically different, and that hybridization is likely to continue to spread if hybrid populations with high amounts of rainbow trout admixture are not reduced or eliminated. I conclude that extant aboriginal cutthroat trout are at greater conservation risk due to hybridization than previously thought and policies that protect hybridized populations need reconsideration.