Theses and Dissertations at Montana State University (MSU)
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Item Evaluating habitat suitability for lesser prairie-chicken conservation in the mixed-grass prairie ecoregion(Montana State University - Bozeman, College of Agriculture, 2022) Solomon, Morgan Jean; Chairperson, Graduate Committee: Lance McNewPopulations of lesser prairie-chickens (Tympanuchus pallidicinctus; hereafter "prairie-chicken") in the southern Great Plains have declined by an estimated 85% and the species is currently being reconsidered for protections under the federal Endangered Species Act. Despite efforts to increase the quantity, quality, and connectivity of available habitat, prairie-chicken populations in the mixed-grass prairie ecoregion have remained relatively stable-to-declining. To provide information that will assist in providing more appropriate qualifications of available prairie-chicken habitat, I used ensemble modeling approaches and a least-cost path analysis to develop spatially-explicit predictions of prairie-chicken habitat and assess connectivity of identified habitat within the mixed-grass prairie ecoregion. In addition, I provided a critical comparison of the Western Association of Fish & Wildlife Agencies (WAFWA) Habitat Evaluation Guide and research-based field indices used to quantify the amount and quality of habitat for prairie-chicken conservation on a proprety participating in an incentive-based conservation program. I also explored the potential for using ecological site descriptions and relative condition (similarity index) to monitor reproductive habitat for prairie-chickens. Predictions from our ensembled model identified ~4,576 km 2 of potentially suitable prairie-chicken habitat both occupied and unoccupied. Least-cost path analyses revealed a low degree of connectivity between areas of occupied and unoccupied habitat indicating a low probability of natural recolonization. Managers should consider focusing conservation efforts on targeting habitat restoration between, within and around areas of identified occupied and unoccupied habitat. Habitat quality under the HEG habitat assessment protocol showed the property had excellent prairie-chicken habitat quality while research-based estimates showed the property only had marginal habitat quality for prairie-chickens. Differences in habitat quality assessments were in areas that had low percent cover of vegetation species preferred by prairie-chickens and in areas that had recently experienced fire. Thus, managers should consider using components of both habitat assessments protocols when quantifying habitat for prairie-chicken conservation to reduce the probability of producing erroneous estimates of habitat quality. Limited sample size within moderate categories of similarity index across ecological sites prevented us from reliably executing further analyses exploring the utility of using a similarity index as a tool for monitoring prairie-chicken habitat.Item Movement ecology of female sage-grouse informs space use, resource selection, and demography in southern Valley County, MT(Montana State University - Bozeman, College of Agriculture, 2023) Haynam, Robert Thomas, III; Chairperson, Graduate Committee: Lance McNew; This is a manuscript style paper that includes co-authored chapters.The greater sage-grouse (Centrocercus urophasianus) is a focal species in the effort to conserve imperiled sagebrush ecosystems and associated organisms. Sage-grouse uses of landscapes are modulated by their multilevel movement processes. Understanding the relative contributions of hard-wired and environmental influences on movement processes is necessary for a comprehensive understanding of sage-grouse ecology. Correlates between fitness components and measurable landscape conditions may be of limited value if other influences such as sage-grouse movement and behavior are not accounted for. Movement behaviors may be risky in certain contexts and adaptive in other contexts, and differences in the characteristics of movement and therefore space-use among individuals can have implications for survival and reproductive performance. We collected detailed records of sage-grouse movements for up to 4 years per individual to investigate daily behavioral strategies of sage-grouse and therefore mechanisms driving habitat use and individual performance. During April-May, 2018-2019, we captured 86 (45 in 2018, 41 in 2019) female sage-grouse and outfitted them with GPS transmitters. We collected 192,640 geographic coordinates of 86 female sage-grouse during 2018-04-24 - 2022-04-14 which encompassed 4 complete annual cycles of sage-grouse. We confirmed 185 nest attempts of 76 individuals during the nesting seasons of 2018-2021. Hard-wired or learned seasonal behavior modes appeared to be more influential than vegetation conditions. Sage-grouse can exhibit reactive responses to landscape conditions but also use the landscape as a function of high-level endogenous constraints likely due to memory mechanisms, high temporal predictability of some resources, and moderate spatial heterogeneity of resources. Management prescriptions may ignore important ecological levels such as those responsible for learned-heuristic movement and space use modes. Relationship and magnitude of associations among sage-grouse use-intensity and landscape conditions varied among 7 behavior modes which indicates that behavioral and temporal context is important for understanding habitat and space use by sage-grouse. Our findings also support a fundamental demographic importance of area affinity, fidelity, and familiarity to sage-grouse ecology which has been overlooked in most research on sage-grouse or other birds.Item The water quality impacts of critical habitat designation for endangered species(Montana State University - Bozeman, College of Agriculture, 2023) Carr, Taurey Rosenhahn; Chairperson, Graduate Committee: Melissa C. LoPaloThe Endangered Species Act of 1973 [ESA] is well-known by environmental economists for its extensive provisions that create a variety of impacts on housing, land development, timber harvesting, etc. However, the ESA's impact on water quality has not been formally studied despite being discussed extensively by federal agencies that administer the Act. I estimate the causal effect of critical habitat designation, an ESA provision that regulates land use, on a range of water quality outcomes. Using administrative data on water quality from 1970-2018, I employ event study and difference-in-differences [DiD] empirical models to evaluate temporal and spatial changes in water quality resulting from plausibly exogenous variation in critical habitat designations. I find null results for most water quality outcomes and mixed evidence of a decrease in pH after designations occur. However, pooled DiD results find no evidence of average declines in pH in the years following designation. Slight declines in pH from the event-study results are concentrated partially in urban areas and primarily around critical habitat designations involving fish species. Results provide some evidence that fish designations may result in more significant water quality impacts after designation across pH and additional outcomes than all designations on average. These results add to a body of research that questions if other species conservation provisions may lead to more efficient outcomes than critical habitat designation.Item Reproductive and juvenile ecology of mountain whitefish in the upper Green River, Wyoming(Montana State University - Bozeman, College of Letters & Science, 2022) Brown, Colter Davis; Chairperson, Graduate Committee: Christopher S. GuyMountain Whitefish Prosopium williamsoni are a salmonid native to the northern Rocky Mountains that has experienced declines in population abundance in rivers throughout Idaho, Colorado, Wyoming, and Montana. Problems with recruitment are suspected, but often the specific mechanisms causing population declines are unknown. Our approach to better understand the mechanisms that influence Mountain Whitefish population dynamics was to compare population characteristics between the Green River, Wyoming and the Madison River, Montana populations. Boyer et al. (2017a) conducted an extensive study on the movement and reproductive ecology of Mountain Whitefish in the Madison River, and we used this study as a template to make direct comparisons between the populations. Our primary research questions were 1) what is the age and length at first maturity, spawning periodicity, fecundity, and age structure of Mountain Whitefish, 2) what is the spatial and temporal distribution of Mountain Whitefish through their spawning period, and what influence do abiotic factors have on spawning and movement, and 3) what is the spatial distribution and habitat use of age-0 Mountain Whitefish? We collected otoliths and gonadal samples from 127 Mountain Whitefish in the Green River, implanted 100 fish with radio transmitters and tracked them from September 1 to early November in 2019 and 2020, determined spawning period and locations using egg mats, kick netting, and angling, and sampled age-0 Mountain Whitefish using a beach seine in slow-water habitats. The geographic separation and difference in hydrogeomorphic conditions between the systems allowed us to form generalizations about Mountain Whitefish in the Intermountain West. We found Mountain Whitefish in both systems mature between ages 2 and 4, primarily spawn annually, have a similar relative fecundity, spawning movements vary, males begin movement prior to females, and age-0 fish drift downstream of spawning locations and use slow-water silt-laden habitats after hatching. The main disparities between systems were that in the Green River water temperature was more suitable for embryo development, and age structure was more uniform and older. This research enhanced our understanding of Mountain Whitefish reproductive and juvenile ecology and provided evidence for factors that may influence recruitment of Mountain Whitefish.Item Retrospective analysis of a declining trumpeter swan (Cygnus buccinator) population in Yellowstone National Park(Montana State University - Bozeman, College of Letters & Science, 2021) Shields, Evan Michael; Chairperson, Graduate Committee: Jay J. RotellaBy 1933, the number of trumpeter swans (Cygnus buccinator) in the continental United States was reduced to roughly 70 individuals that nested and wintered in Yellowstone National Park (YNP) and the surrounding Greater Yellowstone area. While conservation measures saved the trumpeter swan, and their numbers have increased greatly across North America, abundance and productivity of YNP's resident trumpeter swan population declined from the 1960's through about 2010. Many hypotheses for the initial decline in YNP trumpeter swans exist, including human disturbance at nesting areas, changes in habitat quality, predation, and management of trumpeter swans outside of YNP. To improve knowledge and take advantage of long-term monitoring of trumpeter swans, this retrospective study was designed to evaluate the various competing hypotheses about possible factors associated with temporal and spatial variation in swan abundance and reproductive success in YNP for 1931-2019. Two different types of analyses were used: (1) analysis of annual park-wide counts of trumpeter swan territories with swans Absent, Present but unsuccessful (Present), and Successful, and (2) Bayesian reversible jump Markov chain Monte Carlo analysis that evaluated the utility of covariates representing swan decline hypotheses for explaining variation in annual, territory-level patterns of where swans were Absent, Present, and Successful each year. My results provide novel information on temporal patterns in the annual number of Absent, Present, and Successful territories, and analysis of covariates that are useful to explain variation in territory statuses identified several interesting covariate relationships. Swan territories within YNP were more likely to have trumpeter swans Present as opposed to Absent during 1931-2011 in years when total abundance of trumpeter swans in the broader geographic area around YNP was greater. Because several covariates have values that trend through time, it is difficult to distinguish between several alternative interpretations for the underlying causes of temporal trends. Identification of swan territories most likely to have swans Present and Successful can be a useful tool to help YNP staff manage important swan habitat or justify targeted management actions. Future work that utilizes satellite imagery to reconstruct lake/wetland hydrology is likely to be useful to describe potential changes in habitat quality.Item Small scale denil development for use in headwater streams in southwest Montana(Montana State University - Bozeman, College of Engineering, 2021) Conley, Megan Elizabeth; Chairperson, Graduate Committee: Kathryn Plymesser; Katey Plymesser, Kevin Kappenman, Matt Blank and Joel Cahoon were co-authors of the article, 'Arctic grayling (Thymallus arcticus) passage through a scaled denil fishway' submitted to the journal 'Journal of fish and wildlife management' which is contained within this thesis.The Big Hole River is located in an agricultural valley in Southwest Montana and is home to the last fluvial (river dwelling) population of Arctic grayling (Thymallus arcticus) in the contiguous United States. Grayling mostly populate the tributary streams in the upper portion of the watershed, where there are many irrigation diversions, which greatly fragments grayling's natural habitat. While many of these irrigation diversions have fish ladders installed at them to assist with habitat reconnection, these ladder become impassable when the water levels get too low in the system or irrigators chose to block the fish ladders in order to divert more water. This study investigated and characterized a smaller scale Denil fish ladder that would use less water while providing adequate fish passage. Three different flow rate calculations were applied to a series of scaled Denils to compare to the expected flow rates of the full scale Denil to determine the scaled sizes to construct. A 0.6 scale and a 0.75 scale Denil were selected and hydraulic lab testing confirmed that 25.4 cm baffle spacing was the best for both scaled models. The fish swimming study, conducted at the outdoor flume at the Bozeman Fish Technology Center, used eight hatchery-raised grayling in each of the eight treatments. Each treatment was repeated 3 times using the 0.6-scale model for a total of 24 trials with 192 fish. Each treatment used a different combination of headwater depth (between 30.5 cm and 61.0 cm) and tailwater depth (between 15.2 cm and 61.0 cm). The grayling passed with near perfect success at all headwater and tailwater combinations except when the head difference between the headwater and tailwater was at its greatest (61.0 cm headwater and 15.2 cm tailwater). This preliminary study showed that grayling are willing to pass smaller-scale structures at a variety of flow rates but did not test a wide range of slopes, age classes or fish sizes. These results should be useful to water managers when looking to modify or install new Denil fishways in the Big Hole River Basin and around the western United States.Item Combination of acoustic telemetry and side-scan sonar provides insight for lake trout Salvelinus namaycush suppression in a submontane lake(Montana State University - Bozeman, College of Letters & Science, 2021) Siemiantkowski, Michael James; Chairperson, Graduate Committee: Christopher S. GuyExpansion of an invasive Lake Trout Salvelinus namaycush population in Swan Lake, Montana threatens a core area population of Bull Trout Salvelinus confluentus in Montana. Given the increased efficacy of suppression using novel embryo suppression methods, there is renewed interest in Lake Trout suppression in Swan Lake. The specific questions of this study were: 1) where are Lake Trout spawning, 2) where are the most used spawning sites, 3) what is the amount of spawning habitat, 4) does the estimated spawning area differ between estimates from telemetry locations and side-scan sonar imagery of suitable spawning substrate, and 5) how much phosphorous and nitrogen would be added to Swan Lake if carcass-analog pellet treatments were implemented? Acoustic tags were implanted in 85 Lake Trout in July and August of 2018 and 2019. Nightly tracking efforts during September, October, and November of 2018 and 2019 resulted in 1,744 relocations for 49 individual Lake Trout. Kernel-density analysis was used to evaluate Lake Trout aggregation locations identifying 10 distinct spawning sites -- corroborating previous studies. Visual observation of Lake Trout embryos confirmed spawning at three sites with the remaining seven sites considered to be unconfirmed spawning sites. All confirmed spawning sites were located in the littoral zone along areas of steep bathymetric relief and were the most used across both spawning seasons. In 2019, side-scan sonar imaging was used to classify and quantify the total area of suitable spawning substrate, which comprised 12.8% of the total surface area estimated for confirmed sites and 11.4% for unconfirmed spawning sites. Simultaneous treatment of all confirmed and unconfirmed spawning sites would require 205,709 + or - 86 kg of carcass-analog pellet material, resulting in 370.4 + or - 0.2 kg of phosphorous and 7,487.9 + or - 3.1 kg of nitrogen inputs to Swan Lake. Thus, pellet treatment would increase the Carlson's trophic state index (TSI) values from 20.8 to 27.7 for total phosphorous, and from 22.1 to 26.2 for total nitrogen. Based on a TSI threshold value of < 40 for an oligotrophic lake, the use of carcass-analog pellets could be a feasible addition to renewed Lake Trout suppression efforts in Swan Lake.Item Fish assemblage response to habitat restoration in Elk Springs Creek, Montana: implications for arctic grayling (Thymallus arcticus) restoration(Montana State University - Bozeman, College of Letters & Science, 2021) Marsh, Jason William; Chairperson, Graduate Committee: Alexander V. ZaleThe abundance and distribution of Arctic Grayling Thymallus arcticus in Montana have declined substantially during the past century as a result of habitat degradation and loss. Biologists tasked with conserving Arctic Grayling populations in the Centennial Valley of southwestern Montana implemented two habitat restoration projects to reclaim historical Arctic Grayling migration corridors and spawning habitats in Elk Springs Creek. I used before-after and before-after control-impact (BACI) study designs to evaluate the effects of these habitat restoration projects on physical habitat, water quality, and Arctic Grayling in Elk Springs and Picnic creeks. Because Arctic Grayling were rare in Elk Springs and Picnic creeks, I also examined the effects of restoration on two additional species (Brook Trout Salvelinus fontinalis and White Suckers Catostomus commersonii) with habitat requirements and life history characteristics similar to those of Arctic Grayling. I used electrofishing to monitor the abundance, biomass, and size distribution of each species before the restoration in 2016, and after the restoration during 2017 and 2018. A PIT-tag detection network monitored the seasonal movements of Arctic Grayling, Brook Trout, and White Suckers from spring 2016 through autumn 2018. In situ data loggers measured summer stream temperatures and dissolved oxygen concentration in expected fish migration corridors both before and after restoration. The abundances and biomasses of Arctic Grayling and White Suckers were similar before and after restoration. However, Brook Trout abundance and biomass increased significantly in the restored (impacted) reaches relative to the unrestored (control) reaches two years after habitat restoration. The size-class distributions of Arctic Grayling and Brook Trout broadened after restoration. Movements of Arctic Grayling, Brook Trout, and White Suckers among unique habitat segments in Elk Springs and Picnic creeks increased after restoration, but pre-restoration movement data was sparse and limited inference. Following channel restoration, summer stream temperatures decreased, and dissolved oxygen concentration increased and equilibrated. Physical habitat improved (i.e., fine sediments decreased, and depth, percentage of pools, and gravels increased) in restored historical Arctic Grayling spawning areas. I thereby showed that channel reconnection and spawning habitat restoration can substantially improve water quality and physical habitat. However, the restoration measures implemented in Elk Springs Creek affected my target species disproportionately.Item Is habitat constraining bighorn sheep distribution and restoration: a case study in the Greater Yellowstone Ecosystem(Montana State University - Bozeman, College of Letters & Science, 2019) Lula, Ethan Shawn; Chairperson, Graduate Committee: Robert A. GarrottRocky Mountain Bighorn Sheep (Ovis canadensis) restoration continues to be a challenge throughout western North America despite nearly a century of efforts dedicated to the species' recovery. A persistent problem for restoration is populations failing to expand into surrounding areas of habitat even during years of population growth. While populations can be constrained by several environmental factors and behavioral tendencies, we contend habitat availability is not the primary limiting factor. This study incorporated GPS data from bighorn sheep within the Taylor-Hilgard population in the Madison Mountain Range, located in the northwestern extent of the Greater Yellowstone Ecosystem (GYE), to develop summer and winter resource selection function (RSF) habitat models. The objective of this study was to evaluate a hypothesis that habitat was not the primary factor limiting distributions of bighorn sheep within the Madison Range by developing biologically-plausible RSF models and using covariates expected to influence selection. Multiple functional forms and spatial grains for covariates were considered and sets of summer and winter resource selection models compared using AIC subscript c. Results indicated that bighorn sheep resource selection was grain dependent, with bighorn sheep generally selecting covariates at the larger 500 m and 1,000 m spatial grains. Summer selection was characterized by rugged terrain, steep slopes, reduced canopy cover, southwestern aspects and ridgelines. Winter selection was characterized by low elevations, southwestern aspects, steep slopes, reduced canopy cover, ridgelines, high summer NDVI amplitude, and areas close to steep terrain (slopes > or = 45°). Predicted winter habitat occurred in a non-contiguous distribution primarily along low-elevation, southwest-facing aspects within the Madison Valley, and predicted summer habitat was concentrated along high elevation ridgelines. Model results were successfully validated using independent GPS data. Potential abundance for the Madison Range was estimated by linking the winter RSF to population estimates for the Taylor Hilgard and results suggested that the Range may be capable of supporting 2 to 4 times the number of bighorn sheep currently estimated. Study results supported the hypothesis that habitat was not the primary factor limiting extant bighorn sheep populations, suggesting that broader distributions within the Range are possible if novel restoration strategies are considered.Item Recent and historical water use strategies of western U.S. conifers(Montana State University - Bozeman, College of Letters & Science, 2017) Clute, Timothy; Chairperson, Graduate Committee: David Roberts; Jia Hu (co-chair); Jia Hu was a co-author of the article, 'Investigating the variation in inter- and intraspecific physiological plant hydraulic traits across an elevation gradient' which is contained within this thesis.; Jia Hu was a co-author of the article, 'Historic influence of climate on conifer water status in northwestern Montana' which is contained within this thesis.Understanding the physiological traits that trees utilize to manage water use can reveal important insights into how and why they occur in their realized habitat. Among the tools to investigate these traits include measuring trees' seasonal water status, deciphering trees' rooting depth, and measuring the trees' vulnerability to cavitation. However, it is equally important to understand how complex landscape heterogeneity will affect both the inter- and intraspecific variation of these physiological traits. This thesis seeks to quantify the variation of the physiological traits used to manage water status among three common Rocky Mountain conifers; Pseudotsuga menziesii (a plastic species occurring across xeric and mesic sites), Pinus ponderosa (a xeric species), and Picea engelmannii (a mesic species), occurring across an elevation gradient. Furthermore, it aims to link tree maintenance of water status to source water, and understand how the importance of source water is reflected in the tree ring record. In the first chapter, I sought to quantify inter- and intraspecific variation of these three species by measuring diurnal and seasonal water status, seasonal water use, and xylem vulnerability to cavitation at a low elevation xeric site, composed of P. ponderosa and P. menziesii, and a high elevation mesic site, composed of P. engelmannii and P. menziesii. We found good evidence for interspecific variation in the physiological traits to manage water status at both sites. However, we did not find strong evidence for intraspecific variation in these same traits within our plastic species (P. menziesii). In the second chapter, we investigated how stable isotopes in tree rings reflected seasonal source water use as well as the atmospheric conditions the trees were growing under. At the low elevation site, we found evidence that the tree ring isotopes were likely reflecting both seasonal precipitation inputs as well as the atmospheric growing conditions. At the high elevation site, trees likely only reflected the atmospheric growing conditions and did not reflect seasonal water use.