Theses and Dissertations at Montana State University (MSU)
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Item Forecasting vertebrate species habitat suitability and ecoregion types under future climate change scenarios using Species Distribution Modeling (SDM)(Montana State University - Bozeman, College of Letters & Science, 2023) Veneros Guevara, Jaris Emmanuel; Chairperson, Graduate Committee: Andrew J. Hansen; This is a manuscript style paper that includes co-authored chapters.Peru, Ecuador, and Colombia have identified a total of 23 threatened species, including mammals, birds, and plants, which are also a part of their reports for SDG 15. These countries are keen to monitor the risk of extinction of these species and ensure their protection. As part of the Life on Land Project, we aim to assist these countries in approximating the IUCN Red List index using species occurrence data, climatic data, and variables such as Human Footprint (HFP) in different climate change scenario. To achieve this, we conducted a general review of climate drivers and climate change for the three countries and explored climate data to estimate the variation of temperature (°C) and annual precipitation (mm) change under current climate conditions and in RCPs-2050 climate change scenarios (2.6, 4.5, and 8.5). Our results indicated that the average annual temperature for 2050, using a baseline of 1970-2000, is expected to increase by over 1 °C in some areas and over 4 °C in others. For annual precipitation, an increase is also predicted, although few global circulation models show a reduction. We also conducted a median comparison to see the differences between the baseline and the RCPs in 2050, indicating that the medians are different. Density plots were used to illustrate the shift to the right for the temperature case, confirming the anticipated temperature increase by 2050 in the three RCPs. Finally, we used the R package (SDM) to estimate habitat suitability probability for the spectacled bear and the paramo ecoregion. Our findings indicated that climate change impacts their areas with high probability of occurrence to a great extent, and their habitats are also affected by HFP. These methods for exploring climate data and assessing habitat suitability are replicable and can be used with other environmental variables.Item Dynamics of native desert shrubs at restoration plots in the southern San Joaquin Valley, California(Montana State University - Bozeman, College of Agriculture, 2019) Peppel, Landon Charles; Chairperson, Graduate Committee: Scott PowellMy study relied on data accumulated over multiple recent years for shrub restoration at Wind Wolves Preserve, a 37,635 ha nature preserve located in the Southern San Joaquin Valley, California. Shrub species selected for the restoration project focused on creating habitat for threatened and endangered species such as San Joaquin kit fox (Vulpes macrotis mutica), Western burrowing owl (Athene cunicularia hypugea), and blunt-nosed leopard lizard (Gambelia sila). Monitoring data from 541 individual plants across 8 different species and different height classes were examined for survival after the initial planting date. Analysis of variance (ANOVA) was used to compare the relationship to survival and individual shrub species and their heights at planting. Results indicate that certain shrub species survived more frequently than others (p < 0.0001). Plants also varied by height at the original planting date (p = 0.001); however, plant height did not significantly affect dead or alive status (p = 0.76). The results of this study have implications for management decisions for San Joaquin Valley shrub restoration on retired agricultural lands suitable for threatened and endangered species habitat restoration. Future studies might examine more closely the significance of planting date, and the use of other restoration techniques, such as inoculation of arbuscular mycorrhizal fungi.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 An expansion of nonlethal tools for use on juvenile pallid sturgeon in the upper basin of the Missouri River(Montana State University - Bozeman, College of Letters & Science, 2020) Djokic, Matea Asahi; Chairperson, Graduate Committee: Christine Verhille; Kevin Kappenman, Joshua Heishman, Kezia Manlove and Christine Verhille were co-authors of the article, 'Investigations and implications of blood biochemistry, energetic reserves, and visual assessments to assess hatchery-reared juvenile pallid sturgeon health' which is contained within this thesis.; Kevin Kappenman, Joshua Heishman, T. Gibson Gaylord and Christine Verhille were co-authors of the article, 'An assessment of the distell fatmeter for use in juvenile pallid sturgeon (Scaphirhynchus albus)' submitted to the journal 'Transactions of the American Fisheries Society' which is contained within this thesis.Pallid sturgeon (Scaphirhynchus albus) are an endangered species endemic to the Missouri and Mississippi drainages in North America. Mitigation activities including conservation spawning and stocking programs were implemented to prevent extinction of the species. Monitoring of growth, survival, and condition are conducted annually to determine efficacy of managerial efforts to recover pallid sturgeon. My thesis aimed to establish a knowledge base of juvenile pallid sturgeon physiological bioindicators that can supplement field monitoring of growth, size, and condition measurements. Ultimately, I aimed to resolve mechanisms underlying population fluctuations (e.g. growth rate) caused by environmental changes or management actions. Fisheries managers have observed reduced growth rates of recently stocked hatchery origin pallid sturgeon (HOPS) relative to earlier cohorts. Based on high survival rates of historic stocked HOPS, some fisheries biologists hypothesize that growth rates of recent HOPS cohorts reflect compensatory density dependence in growth caused by overstocking. However, size, growth, and condition metrics commonly tracked on wild-captured sturgeon cannot assess underlying mechanisms driving trends in population growth rate. The purpose of this hatchery-based research was to explore nonlethal physiological measurements to expand the toolset available to managers to assess the status of physiological processes within HOPS that may reflect ecosystem effects on these fish. I investigated a suite of physiological bioindicators that could reflect key physiological processes (nutrition, tissue damage, and chronic stress) expected to respond to common ecosystem stressors. I determined reference intervals for 13 blood biochemical analytes on a population of healthy hatchery-reared juvenile pallid sturgeon (n = 41). Inter-individual variation in blood biochemical analytes and five additional physiological variables were analyzed to determine composite variables predictive of growth. To investigate nonlethal tools to quantify whole-body energetic reserves of juvenile pallid sturgeon, I determined best-fit predictive models to estimate whole-body energy (df = 33; R 2 = 0.40; p < 0.001) and lipid (df = 33, R 2 = 0.45, p < 0.001) content using Distell Fatmeter and mass measurements. Research presented in this thesis aims to provide a preliminary understanding of expected ranges of various physiological bioindicators and methods for nonlethally measuring these bioindicators in hatchery-reared juvenile pallid sturgeon.Item Assessing the impacts of protection gradients on large African carnivore density and survival : an example with African lion and leopard in the Luangwa Valley, Zambia(Montana State University - Bozeman, College of Letters & Science, 2016) Rosenblatt, Elias Goldsmith; Chairperson, Graduate Committee: Scott Creel; Matthew S. Becker, Scott Creel, Egil Droge, Thandiwe Mweetwa, Paul A.Schuette, Fred Watson, Johnathan Merkle and Henry Mwape were co-authors of the article, 'Detecting declines of apex carnivores and evaluating their causes: an example with Zambian lions' in the journal 'Biological conservation' which is contained within this thesis.; Scott Creel, Matthew S. Becker, Johnathan Merkle, Henry Mwape, Paul Schuette, Twakundine Simpamba were co-authors of the article, 'Effects of a protection gradient on carnivore density and survival: an example with leopards in the Luangwa Valley, Zambia' in the journal 'Ecology and evolution' which is contained within this thesis.; Elias Rosenblatt was a co-author of the article, 'Using pedigree reconstruction to estimate population size: genotypes are more than individually unique marks' in the journal 'Ecology and evolution' which is contained within this thesis.Large carnivores are in rapid global decline, primarily due to anthropogenic pressures. Human activities on the periphery of protected areas can limit carnivore populations, but measurements of the strength of such effects are limited. Both African lion (Panthera leo) and leopard (Panthera pardus) are declining throughout their ranges, and thus accurate monitoring of key populations is critical. Both of these species face pressure from encroaching human populations, particularly from trophy hunting, illegal bushmeat harvest, and human-carnivore conflict. In Zambia, South Luangwa National Park and its buffer areas are thought to contain the country's largest lion and leopard populations. However, this protection gradient is experiencing rapid human population growth and activities that are known to threaten large carnivore populations elsewhere. Here we examined the status and major anthropogenic drivers of the South Luangwa lion and leopard populations. First, we estimated population size, trends, survival rates and demography for the South Luangwa lion population from 2008 to 2012. These data indicated that trophy hunting was impacting the South Luangwa lion population, and potential management actions exist and should be implemented to mitigate impacts from trophy hunting. Second, we measured how the density and survival rates of South Luangwa's leopard population varied across this gradient of protection using remote camera trap surveys from 2012-2014 during a ban on trophy hunting. We estimated that leopard density was higher inside South Luangwa National Park as compared to an adjacent buffer area with lower levels of protection, but could not detect differences in leopard survival across these two areas. This difference in density was most likely driven by prey depletion in the buffer areas, and this limitation is likely an issue for other sympatric large carnivore species. Finally, we developed a rapid survey method based on pedigree reconstruction to estimate population size, with validation based on a simulated population. This method shows promise for surveying unstudied large carnivore populations. Overall, large carnivore populations face growing anthropogenic pressures worldwide, and management action to mitigate population declines must be informed by intensive monitoring of key large carnivore populations to identify the drivers and dynamics of such declines.Item Analysis of the listing of species as endangered or threatened under the Endangered Species Act(Montana State University - Bozeman, College of Letters & Science, 1993) Easter-Pilcher, Andrea L.Item A multistate mark recapture analysis to estimate reproductive rate in the Steller sea lion (Eumetopias jubatus), an endangered species(Montana State University - Bozeman, College of Letters & Science, 2009) Taylor, Rebecca Lynn; Chairperson, Graduate Committee: Daniel GoodmanThe Steller sea lion is an endangered species whose reproductive rate estimates need to be updated. The species is divided into two populations: the endangered western population has declined over 80% from historical levels, while the threatened eastern population has been increasing at approximately 3% for the past three decades. The statistically most compelling reproductive rate estimates for this species are based on now out of date population dynamics, and hence are not applicable to current concerns. Extensive recent branding and resighting efforts by the Alaska Department of Fish and Game in Southeast Alaska make possible an updated estimation of eastern population Steller sea lion reproductive rates. However, the complexity of these data required a different statistical approach than is typically used to estimate reproduction in marked and resighted animals. I developed a novel statistical analysis, based upon a multistate mark recapture likelihood function, specifically to analyze the Southeast Alaska Steller sea lion data. The likelihood function estimates a reproductive rate when only adult females (not pups) are marked, female sightability is correlated with reproductive status, state classification uncertainty is present and the population is open to births during many of the resighting intervals. I apply this analysis to the Southeast Alaska Steller sea lion data and estimate a reproductive rate of 0.66 (0.55, 0.77). Not only does this provide a reproductive rate estimate for the eastern population, which is important for monitoring its health, but it also provides a basis for comparison to the endangered western population. Furthermore, the Alaska Department of Fish and Game continues to have an active branding and resighting program. The methods developed here can be applied to future data collected in either population.Item The influence of riparian-canopy structure and coverage on the breeding distribution of the southwestern willow flycatcher(Montana State University - Bozeman, College of Letters & Science, 2005) Brodhead, Katherine May; Chairperson, Graduate Committee: Richard J. AspinallThere is a long history of relating bird species diversity and distributions to heterogeneity in foliage structure as seen from within the habitat and measured from the ground up. There is also an overwhelming contribution in the literature promoting and justifying a broad-scale approach to characterizing spatial patterns, especially for the purpose of relating to, and predicting, species distributions. This study draws from the relationship between birds and habitat structure but assesses heterogeneity in structure from a broader perspective. For this analysis, I compared the spatial distribution of a breeding population of the southwestern willow flycatcher (Empidonax extimus traillii) to the structure of a riparian zone with an emphasis on capturing patterns that are measured horizontally across the zone. Riparian zones are dynamic by nature and are structurally diverse in a natural, healthy system, and support a high density of breeding birds. The flycatcher prefers dense riparian habitat in close proximity to lentic water. The structural characteristics of the riparian zone where dense vegetation and water are present were hypothesized to be more structurally heterogeneous and to support a broader riparian zone. Riparian zone structure was mapped and stand characteristics were extracted, with the intent of relating spatial patterns in stand heterogeneity and riparian extent to the spatial distribution of the southwestern willow flycatcher. A moving window function in a GIS assessed the stand characteristics, which were imported as attributes to presence/absence data points. The extent of the analysis window was varied to determine the scale at which the habitat characteristics were most highly correlated with flycatcher presence. Correlation between the structural characteristics of the stand and the presence/absence of the flycatcher was modeled with logistic regression. Results show the flycatcher is more likely to occupy habitat that is structurally heterogeneous and has more riparian vegetation. The results also show that selection is most sensitive to habitat characteristics within a relatively close proximity.