Theses and Dissertations

Permanent URI for this collection

https://hdl.handle.net/10217/100425

Of special note are theses cited in James R. Meiman's Little South Poudre Watershed and Pingree Park Campus (Colorado State University, College of Forestry and Natural Resources, 1971).

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Determining the impact of harvest and climate change on the demography of black brant (Branta bernicla nigricans)
(Colorado State University. Libraries, 2024) Blommel, Caroline, author; Koons, David, advisor; Aubry, Lise, committee member; Webb, Colleen, committee member
As a coastal long-distance migrant, black brant (Branta bernicla nigricans) are vulnerable to climate and land-use change while also facing harvest pressure from sport hunting along the Pacific Coast. To examine impacts of harvest pressure and environmental change on brant survival and reproductive components of fitness, I combined band-recovery data with live recapture and resighting data from 1990 to 2023 for the Tutakoke River breeding colony of brant on the Yukon-Kuskokwim Delta in western Alaska. I fit multiple Bayesian multistate mark-recapture models to these data to estimate temporal changes in cause-specific mortality and breeding probabilities over the last 33 years. Harvest rate increased over time and is significantly impacted by bag limit across sex and age groups. Adult non-harvest mortality has remained stable over the study period but is higher in years of extreme El Niño and Aleutian Low Beaufort Sea Anticyclone events. Breeding probability for previous breeders increased over time while breeding probability for previous non-breeders decreased, driven largely by differing responses to spring timing. My work describing brant demographic response to environmental change and harvest provides valuable information on how to manage brant most effectively across their migratory range.
Open Access
Effects of a non-lethal chemical repellent on airport bird communities
(Colorado State University. Libraries, 2024) Urchek, Kathleen, author; Pejchar, Liba, advisor; Werner, Scott, committee member; Kendall, William, committee member; Bright, Alan, committee member
Human-wildlife conflicts are likely to occur wherever the interests and activities of humans and wildlife overlap. Airport environments are a prime example of where such conflict is pervasive because wildlife can view airports as habitat, yet the presence of wildlife increases the risk of collision. As humans increase our reliance on air travel and development encroaches on natural areas, conflicts between humans and wildlife will continue to be prevalent in airport settings, thus creating the need for effective management tools. To assess the effectiveness of one such tool, we evaluated the effect of a non-lethal chemical repellent on bird abundance, species richness, movement, and behavior in airport settings. Following a Before After Control Impact Paired study design we compared the changes among each variable from a period of pre-treatment to a period of active treatment, in both treated and control sites. Using Poisson and zero-inflated mixed effects models we found that the repellent is likely effective in shifting birds from treated to untreated areas within airports, and that the abundance of two common species, Bobolinks and European Starlings, declined following treatment. We also found that the repellent does not change the frequency in which birds move out of treated plots and intersect with runways, but may be altering the within-plot behavior of Eastern Meadowlarks, Red-winged Blackbirds, and Sandhill Cranes. Our mixed findings highlight the need for continued study of the mechanisms behind avian response to chemical repellents in airport settings. Although a diverse set of approaches will always be needed to alleviate the many human-wildlife conflicts associated with airports, here we show that, to promote co-existence with wildlife, this chemical repellent can be a part of that toolset.
Open Access
Occupancy dynamics of barred owls on a spotted owl landscape
(Colorado State University. Libraries, 2024) McGee, Kaitlin R., author; Doherty, Paul, Jr., advisor; Franklin, Alan B., advisor; Bailey, Larissa, committee member; Hart, Sarah, committee member
Invasive barred owls (Strix varia) pose a significant threat to native northern spotted owls (Strix occidentalis caurina) in western North America. Barred owls compete with northern spotted owls for resources and habitat, leading to displacement and subsequent declines in northern spotted owl populations. This impact highlights the need for conservation efforts to mitigate the negative consequences of barred owl presence in spotted owl habitats. In my thesis, I explored barred owl habitat use in northern California using data on both lethal removals of barred owls and barred owl occupancy of non-removal areas from long-term studies. These studies provided a unique opportunity to study associations of barred owl land use both during initial colonization and over time. Barred owl land use was influenced by landscape factors such as topographic water accumulation, forest age, tree composition, and canopy cover as well as interspecific effects of northern spotted owls. I used these results to predict variation in barred owl use of landscapes, which can then focus barred owl management efforts in California.
Open Access
Home range estimates, habitat selection, and nesting behavior of Ferruginous Hawks (Buteo regalis) in western Wyoming
(Colorado State University. Libraries, 2024) Ramirez, Sarah Kathleen, author; Pejchar, Liba, advisor; Koons, David, committee member; Angeloni, Lisa, committee member
Oil and gas development has the potential to negatively impact wildlife, but the consequences for some raptor species are less well understood. Ferruginous Hawks could be particularly susceptible to negative effects due to their large habitat requirements and sensitivity to anthropogenic disturbance. Given the rapid expansion of oil and gas development in many parts of the range of Ferruginous Hawks, it is critical to evaluate habitat use in both a pre-construction and post-construction environment. Understanding selection of habitat resources and nest sites, as well as the factors that contribute to home range estimates, nest success and nest productivity could help inform efforts to mitigate against potential negative effects of land use change. In my first chapter, I aimed to investigate factors associated with breeding Ferruginous Hawk home range estimates and habitat selection in a landscape slated for energy development. In a sagebrush-steppe study site in western Wyoming, I captured breeding hawks and used radio and satellite-telemetry to collect location data, estimate home range estimates, and model habitat selection. Home range estimates were smaller for females and hawks with egg-laying breeding status, and larger with increasing numbers of producing wells. Ferruginous Hawks selected habitat with high terrain ruggedness, low shrub cover, and areas closer to primary prey, and avoided areas with high density of wells. The relationship between lagomorph density and distance to development was dependent on scale. My findings show that home range estimates are smaller in my study relative to other parts of the species' range, and that future energy development is likely to reduce habitat quality and availability for Ferruginous Hawks. In my second chapter, I investigated the factors associated with nest site selection, success, and productivity in the same study site in western Wyoming. I used an existing dataset on nest site locations, nest success, and productivity, and collected new data on these response variables between 2019 and 2023. I used a resource selection function model (RSF) to evaluate nest site selection and used generalized linear mixed models (GLMMs) to evaluate nest success and productivity. Ferruginous Hawks selected nest sites in developed-open space landcover (e.g., areas cleared of vegetation with little or no infrastructure), higher topographic position index (TPI), and in closer proximity to producing wells (km). In contrast, breeding hawks avoided nest sites in areas with higher densities of producing wells (per km2) and more shrub cover (%). Nest success and productivity of egg-laying pairs was positively associated with artificial nesting platforms (ANPs) and negatively associated with anthropogenic structures and rocky outcrops, developed-open space landcover, TPI and year. These findings suggest that Ferruginous Hawks may be subject to an ecological trap when they nest on anthropogenic structures, but that ANPs are a potentially viable tool for mitigation.
Open Access
Assessing the swimming and jumping performance of Wyoming fishes with implications for fishway design
(Colorado State University. Libraries, 2024) Garvey, Chase, author; Myrick, Christopher A., advisor; Kanno, Yoichiro, committee member; Wohl, Ellen, committee member
To successfully begin to solve the complex problems facing native fish conservation efforts, we need to seek a deeper understanding of the fish that inhabit the communities that we hope to conserve. With regards to the issue facing the fragmentation of our lotic ecosystems, and the effects that dams and similar structures can have on fish communities, fishways are a common tool used to restore the connectivity of streams by allowing the uninhibited passage of fish. In these experiments we studied the swimming and jumping abilities of Hornyhead Chub (Nocomis biguttatus), Bigmouth Shiner (Notropis dorsalis), Iowa Darter (Etheostoma exile), and Brook Stickleback (Culaea inconstans) in order to provide fisheries managers with criteria for fishway design that will allow the passage of desirable target species, and potentially block the spread of invasive Brook Stickleback. We did this by testing the jumping abilities of each species at various temperatures using artificial waterfalls. After testing groups of fish at various waterfall heights, we used logistic regression to predict the probability of individual fish passage under various conditions. To test the swimming ability of each species, we used swim tunnels to determine the maximum swimming velocity of each species, and estimate their endurance at various swimming velocities. Our results show that a vertical barrier greater than 15 cm will block the upstream movement of nearly all individual Hornyhead Chub. Heights greater than 8.4 cm will block the upstream passage of Bigmouth Shiner, and barriers taller than 6.0 cm will block the upstream passage of Iowa Darter and Brook Stickleback. Given this information, if vertical drops and pool designs were to be incorporated into fishways designed for these species, drops between fishway pools should remain within these thresholds if successful passage is to be achieved. The results of the swimming performance experiments show that each species' swimming abilities are unique relative to their raw maximum swimming abilities and overall endurance. The problem facing engineers and biologists is that many different species that make up these communities are unique, and have characteristics that pose specific challenges or advantages to assisting their movements. Additionally, fisheries scientists must remain cognizant that fishways that allow native fish movement will likely allow the movement of non-target species (including potential invasives) present in the same systems. Managers must balance the trade-offs between restoring native ecosystems and protecting areas that have not been invaded.
Open Access
Developing rock ramp fishway criteria for fishes of regional conservation concern
(Colorado State University. Libraries, 2024) Paik, Kira, author; Myrick, Christopher A., advisor; Kanno, Yoichiro, committee member; Wohl, Ellen, committee member
Rivers and streams in the United States have been greatly fragmented by the construction of instream structures such as dams, diversions, and culverts to meet the growing needs of human populations. Many of these structures inhibit upstream movement by fish species, negatively affecting abundance as well as overall survival. Conservation efforts are looking at restoring connectivity through the installation of fish passage structures or fishways. To improve effectiveness and functionality of these fish passage structures, the swimming abilities of the target species should be considered when creating the design. Rock ramp fishways are becoming increasingly utilized because they can allow passage of a large assortment of species with variable swimming abilities and are highly customizable. Creating cast concrete fishways in this style can also help to reduce the cost of construction of passage structures. We evaluated the passage success of five fish species of conservation concern using an experimental rock ramp fishway at slopes of 2-10%, in 2% increments. This study focused on species of national or regional conservation concern including Topeka Shiner Notropis topeka, Suckermouth Minnow Phenacobius mirabilis, Rio Grande Chub Gila pandora, Rio Grande Sucker Catostomus plebeius, and Mottled Sculpin Cottus bairdii. Our results showed that decreased slope and distances would lead to higher passage success for the five species. For the entire length of the fishway (6.1 m), all species had very high passage probabilities (> 0.9) at the lowest slopes 2 and 4%, and for all species except the Topeka Shiner, the 6% slope also had high passage probabilities (> 0.8). At 8% and 10% slopes, passage success for these species decreased drastically (< 0.31) and would not be recommended for longer fishways (> 2.03 m between resting areas). Based on these results, managers designing fishways for these species should be able to pick ideal combinations of slope and length to successfully allow passage of an acceptable proportion of the fish to attain management goals.
Open Access
Avian conservation and ecology in northern Vietnam
(Colorado State University. Libraries, 2009) Vu, Thinh Tien, author; Doherty, Paul F., Jr., advisor; Huyvaert, Kathryn, advisor
Due to the rapid rate of biodiversity loss in Vietnam conserving the avian biodiversity is a contemporary issue of concern and my dissertation was aimed at several issues focused on avian conservation. Recently, the number of non-native tree plantations has increased but the conservation potential of such plantations remains unknown. In Chapter 1, I estimated bird species richness to be highest in mature natural forest, lower in second-growth natural forest, and lowest in pine plantation. I suggest that natural forest types should receive priority for conservation in Vietnam. In Chapter 2, I compared bird movement over a paved road (6-8m wide) and within forest interior plots. The probabilities of approaching the playback for ground species at the road site were lower than those in the forest interior. The road seems to moderately affect the ability for ground-feeding bird species to cross gaps. Roads in the natural reserves should be designed to be as narrow as possible. In Chapter 3, to investigate the effects of logging on biodiversity, I modeled the recovery of avian communities following a variety of potential logging schemes. I found that, to conserve 80% of the species pool, logging schemes with either cycle length > 40 years or wood volume left after harvest > 55% should be implemented. Wildlife diseases are raising concerns with respect to human and domestic animal health, as well as the persistence of wildlife populations. Chapter 4 was aimed at characterizing the sample prevalence of avian malaria in wild land birds. The prevalence of avian malaria was 45.85%. However, higher parasite prevalence was observed in flocking species compared to solitary species and higher parasite prevalence was observed in adult birds compared to juvenile birds. In Chapter 5, I focused on surveillance for the presence of avian influenza virus nucleic acids and antibodies in wild land birds. Serum samples from four birds out of 197 birds sampled were antibody positive for the H5 subtype. Sample prevalence for avian influenza virus nucleic acids was 7.25%. This result suggests that attention should be given to land birds in AI surveillance and monitoring programs.
Open Access
Generalized mixed effects models for estimating demographic parameters with mark-resight data
(Colorado State University. Libraries, 2008) McClintock, Brett Thomas, author; White, Gary C., advisor
Mark-resight methods constitute a slightly different type of data than found in traditional mark-recapture, but they are in the same spirit of accounting for imperfect detection towards reliably estimating demographic parameters. Compared to mark-recapture, mark-resight can often be a less expensive and less invasive alternative in long-term population monitoring programs. However, the mark-resight estimators developed to date do not provide a flexible framework allowing the efficient use of covariates in modeling the detection process, information-theoretic model selection and multimodel inference, and the joint estimation of abundance and related demographic parameters. Here I develop a series of mark-relight models for the sampling conditions most often encountered in these studies that address this need for a more generalized framework. In Chapter 1, I introduce the the logit-normal mixed effects model (LNE) for estimating abundance when sampling is without replacement and the number of marked individuals in the population is known exactly. I compare the model to other mark-resight abundance estimators when applied to mainland New Zealand robin (Petroica australis) data recently collected in Eglinton Valley. Fiordland National Park. I also summarize its relative performance in simulation experiments. It can often be difficult to achieve sampling without replacement or to know the exact number of harked individuals in a population. In Chapter 2, I address these limitations of LNE by introducing the (zero-truncated) Poisson-log normal mixed effects abundance model, (Z)PNE. I demonstrate the use and advantages of (Z)PNE using black-tailed prairie dog (Cynomys ludovicianus) data recently collected in Colorado. I also investigate the expected relative performance of the model in simulation experiments. In Chapter 3, I extend (Z)PNE to a full-likelihood robust design model analogous to that used in mark-recapture for the simultaneous estimation of abundance, apparent survival, and transition probabilities between observable and unobservable states. I illustrate the use of the model with additional New Zealand robin data collected in Fiordland National Park, New Zealand. I also report on a series of simulation experiments evaluating the performance of the model under a variety of sampling conditions.
Open Access
Effects of groundwater withdrawal and drought on native fishes and their habitats in the Arikaree River, Colorado
(Colorado State University. Libraries, 2009) Falke, Jeffrey Arron, author; Fausch, Kurt D., advisor
Great Plains streams are harsh environments for fishes, and are increasingly degraded by human-caused impacts, including overuse of groundwater. Plains stream fishes are in decline, due in part to interactions between natural drought and anthropogenic stream drying. To address these issues, in a collaborative study we developed a model of groundwater and surface water that predicted fish habitat quantity within the Arikaree River basin in eastern Colorado into the future, based upon three scenarios of land and water use (e.g., irrigation pumping). We found that under the status quo of pumping, >50% of remaining refuge habitats in the wettest segment of river will be dry in 35 years, and will be isolated in a 1-km fragment along the river. Loss of critical habitats due to stream dewatering, and subsequent negative effects on native fishes, are not unique to eastern Colorado but are in fact widespread across the western Great Plains. Secondly, to set this research in context, I conducted a review of metapopulation and metacommunity research in the stream fish literature. Stream fish populations and communities are spatially structured at multiple scales, and easily fragmented. To date, this spatial structure has not been incorporated into stream fish population and community models. However, recent research in this area should improve our understanding of processes that regulate stream fish assemblages. Next, I developed a spawning phenology for Arikaree River fishes and found that cumulative growing season degree days had the strongest effect on hatching initiation. Occupancy by larvae of most species was related to local scale spawning habitat characteristics (e.g., habitat size and type). Among years, colonization and extinction rates for individual species differed in segments that were fed by groundwater, versus those that were not, and were influenced by climate variability among years. Last, I investigated when and where the threatened brassy minnow, Hybognathus hankinsoni, spawns, and what environmental factors influence growth and survival of this species within and among years. Interannual variability in climate, and the hydrologic context of segments along the riverscape, had a strong influence on habitat availability and recruitment of brassy minnow in the Arikaree River.
Open Access
Cold summer stream temperatures reduce recruitment of native cutthroat trout populations
(Colorado State University. Libraries, 2007) Coleman, Mark Anthony, author; Fausch, Kurt D., advisor
Translocation is a key strategy for conserving subspecies of native cutthroat trout Oncorhynchus clarkii, which have declined markedly throughout their native ranges in North America. Previous research showed that translocation success in high-elevation southern Rocky Mountain streams was more likely in warmer streams, and suggested that cold temperatures could limit juvenile trout recruitment and explain translocation failures. However, the effects of cold temperature on recruitment had not been previously investigated. I studied these effects using an integrated laboratory and field approach. In the lab, age-0 Colorado River cutthroat trout O. c. pleuriticus were subjected to one of three natural temperature regimes during two years, which averaged 7°C, 8.5°C and 10.0°C during the warmest summer month. From hatching to swimup, mean survival was high during both years, ranging from 97% (warm regime) to 85% (cold). After swimup, warm regime fry had much greater survival and grew more than 60% larger, on average, than cold regime fry by the onset of winter in the 2003 experiment. The pattern of lower survival in colder temperature regimes held through mid-winter, with 76% survival (warm regime), 62% (intermediate), and 29% (cold). Likewise, during the 2004 experiment, survival to early winter ranged from 44% (warm regime) to 10% (cold). Most mortality in all treatments occurred during a recruitment bottleneck encompassing a 4- to 6-week period following swimup. A response surface analysis of percent dry weight data indicated that the energy content of fry at swimup was lower in colder regimes, and declined during the recruitment bottleneck in all regimes. In the field, I monitored temperatures and conducted surveys to estimate densities of age-0 fry at peak emergence in six headwater streams that varied in thermal characteristics. Density and growth increased with Celsius degree days during the growing season. My results indicate a strong recruitment bottleneck after swimup, when temperature-related energy deficits probably cause significant mortality. Fisheries managers in the southern Rocky Mountains may increase translocation success of native cutthroat trout by selecting sites with ≥800-900 degree days during the growing season, and fry grow to ≥30-35 mm by the end of the growing season.
Open Access
Bayesian analysis of age-at-harvest data with focus on wildlife monitoring programs
(Colorado State University. Libraries, 2007) Conn, Paul Bayne, author; White, Gary C., advisor
State and federal agencies often collect hunter harvest data at check stations. When age- and sex-classes can be determined at the time of harvest, such data provide a wealth of information about population structure. For instance, such summaries are used extensively in quantitative fisheries stock assessment. However, statistically defensible approaches for using age-at-harvest data to monitor terrestrial wildlife populations have not appeared until quite recently, and are deficient in several respects. The primary focus of this dissertation is on developing better methods for analyzing wildlife age-at-harvest data, and on applying these methods to real and hypothetical populations. Chapter one starts by developing statistical methods necessary for fitting population dynamics models to age-at-harvest data. As an example, I analyze marking and harvest records from female black bears (Ursus americanus) in Pennsylvania. In chapter two, I describe numerical implementation issues, as well as results from several extensive rounds of simulation testing. I show that Markov chains will typically need to be quite long to accurately summarize the posterior distribution of model parameters. Nonetheless, estimators are shown to display little bias, to have satisfactory credible interval coverage, and to have a high degree of precision. I show that abundance estimators are quite robust to aging errors, although using data from marked animals twice may lead to overstated measures of precision. In chapter three, I conduct a power analysis to determine if it would be feasible to monitor black bear in Colorado with age-at-harvest and radio telemetry data. My focus in this chapter is on detecting and estimating population trend for varying levels of effort. I show that five year studies are typically too short for all anticipated levels of marking effort, but that ten year studies can yield meaningful estimates of population trend. In chapter four, I address methods that can be used to correct age-at-harvest data for misclassification errors. When the aging criterion is inexact, it is possible to correct for errors if additional information is available on error rates. I illustrate proposed methodology with a black bear dataset from Pennsylvania.
Open Access
Effect of enhanced nutrition during winter on the Uncompahgre Plateau mule deer population
(Colorado State University. Libraries, 2007) Bishop, Chad Jeffrey, author; White, Gary C., advisor
Mule deer (Odocoileus hemionus) populations declined across much of the West during the 1990s, prompting state wildlife agencies to explore mule deer limiting factors. The greatest concern of agencies and sportsmen was whether declining habitat quality, predation, or both were responsible for the observed declines. In Colorado, the Uncompahgre Plateau mule deer population received the most attention because of a steep population decline from the 1980s through the late 1990s. Biologists hypothesized that poor quality of the pinyon (Pirns edulis) and juniper (Juniperus osteosperma) winter range was the primary cause of the observed decline. In contrast, many of the Colorado Division of Wildlife’s (CDOW) constituents hypothesized that high predation rates were keeping the mule deer herd below nutritional carrying capacity. These hypotheses represented very different paradigms of population limitation. Perhaps more importantly, the competing views suggested that CDOW should pursue one of two very different management strategies: 1) implement habitat improvements in the pinyon-juniper winter range, or 2) implement efforts to reduce predator populations, particularly coyote (Canis latrans) populations. Information was needed to guide the decision process. I therefore evaluated the effect of enhanced nutrition during winter on the Uncompahgre deer population as a way to evaluate the importance of habitat quality versus that of predation.
Open Access
Seasonal trophic niche dynamics of mottled sculpin and juvenile brown trout in a regulated Rocky Mountain river
(Colorado State University. Libraries, 2023) Platis, Nitsa, author; Kanno, Yoichiro, advisor; Johnson, Brett, advisor; Kampf, Stephanie, committee member
In temperate ecosystems, resource availability fluctuates seasonally due to changes in environmental conditions and productivity throughout the year. Intra- and inter-specific trophic niche overlap under resource limitation is a measure of competitive interactions and influences species coexistence and community dynamics, but patterns of this overlap are highly variable among regions and communities. In this study, we analyzed stomach content samples and stable isotope signatures to evaluate seasonal trophic niche dynamics of mottled sculpin Cottus bairdii (80-130 mm total length) and juvenile brown trout Salmo trutta (80-200 mm) in the Blue River, Colorado, USA, where aquatic production varies seasonally and has been reduced due to upstream dams. Prey biomass (i.e., benthic macroinvertebrates) peaked in spring and declined through summer and autumn. Stomach content and stable isotope analysis results revealed diet composition of mottled sculpin and brown trout shifted seasonally in response to changes in resource availability. In autumn, both species exhibited the highest frequency of empty stomachs and expanded population trophic niches due to increased inter-individual diet variation despite decreased individual trophic niche breadth. Interspecific trophic niche overlap was relatively high across all seasons, but the lowest degree of overlap occurred in autumn of both years. Isotopic analysis revealed similar trends of wider isotopic niches and reduced overlap in autumn compared to spring. Taken together, our data indicate that seasonal variation impacts individual and population-level trophic niche dynamics, as well as interspecific niche overlap between mottled sculpin and juvenile brown trout. These two species occur sympatrically in many coldwater streams throughout North America, and our findings indicate trophic segregation under resource limitation may serve as a mechanism that facilitates their coexistence.
Open Access
Provisioning and nest success of an aerial insectivore at a high elevation breeding site
(Colorado State University. Libraries, 2023) Simons, Victoria F., author; Horton, Kyle G., advisor; Doherty, Paul F., Jr., committee member; Ruegg, Kristen C., committee member
Tree Swallows (Tachycineta bicolor) are a model organism in ornithology. However, few studies have been conducted in the western portion of their breeding range, particularly at high elevation. High elevation habitats, like Colorado State University's Mountain Campus, are impacted by climate change. Tree Swallows in these ecosystems face threats due to recent population declines and climate-related changes. These challenges could impact the species' survival in these areas, and for my Master's thesis I investigated two aspects of provisioning behavior, namely weather conditions and insect abundance. My first chapter focused on how daily weather conditions influenced female Tree Swallow's rates of nest visitation and food provisioning. Using radio-frequency identification technology, I compared visitation rates to hourly weather conditions. I found that poor weather, including cooler temperatures and precipitation events, was negatively correlated with the number of visits made to the nest, which subsequently influenced the growth and development of nestlings. In Chapter 2, I addressed the question of how weather affected food availability. Tree Swallows rely on flying insects as their main food source, and inclement weather is known to decrease insect availability in the airspace. To investigate if lowered female provisioning effort matched periods of food unavailability, I deployed a mobile radar unit – the BirdScan MR1 – to quantify insect abundance. I then compared insect activity to nest visitation rates and found that females made significantly more visits to their nestlings when insects were more abundant. Additionally, I found that insect activity was significantly influenced by weather conditions, demonstrating that weather may be used as a proxy for insect abundance at sites where direct monitoring of insects is not possible. Put together, the results of my first and second chapters deepen our understanding of how female Tree Swallows navigate the complexities of aerial conditions – both biotic and abiotic – to forage and provision for their growing nestlings in an ever-changing high elevation environment. As the effects of climate change become more pronounced, high elevation habitats are likely to undergo rapid changes. Consequently, insight into the relationship between weather and food availability becomes increasingly important.
Open Access
Influence of abiotic and biotic factors on the response of benthic macroinvertebrates to metals
(Colorado State University. Libraries, 1995) Kiffney, Peter Michael, author; Clements, Will, advisor; Fausch, Kurt D., committee member; Kondratieff, Boris C., committee member; Chapman, Phillip, committee member
Stream ecologists are well aware that chemical, biological, and physical characteristics of lotic systems vary spatially and temporally. With this in mind, I designed a series of experiments and field studies to examine the role of spatial variation in stream benthic macroinvertebrate communities in response to metals. Specifically, I tested the hypothesis that stream invertebrate communities from pristine streams of different size and altitude varied in their response to metals. To evaluate how metals affected biotic interactions, I manipulated invertebrate density, predation intensity, and metals in stream microcosms. Using stream invertebrate communities, I also designed an experiment and field survey to identify reliable bioindicators of metal contamination in western streams. Results from microcosm experiments and field studies showed that benthic invertebrate populations from high-altitude streams were more sensitive to the effects of metals than invertebrate populations from low-altitude streams. For example, Baetis sp. and Rhithrogena hageni from Little Beaver Creek (LBC), Colorado, (high-altitude stream) were significantly more sensitive to zinc than the same species from the South Fork of the Poudre River (SFP) (low-altitude stream) in stream microcosms. Results from field surveys showed that densities of most groups of aquatic insects (e.g., Ephemeroptera, Plecoptera, Trichoptera) were lower at high-altitude metal contaminated streams than those same groups at low-altitude streams. Other factors, such as variation in water temperature or nutrient concentrations between high- and low-altitude streams, could be lll responsible for these differences. However, because invertebrate responses were similar under controlled and field conditions, I hypothesize that differences in abundances between reference and contaminated locations was a result of metals. To determine if body size contributed to the variation in sensitivity of insects to metals, size measurements were made on species collected from LBC (high-altitude) and SFP (low-altitude). Measurements were also made on species from control and metal-treated stream microcosm. Most species were smaller at LBC (high-altitude stream) than the same species from SFP (low-altitude stream). For example, the mayfly Baetis tricaudatus and the caddisfly Arctopsyche grandis were significantly larger at SFP than LBC. In addition, insect body size was larger in metal-dosed microcosms than in controls. Brachycentrus sp., B. tricaudatus, R. hageni, Eohemerella infrequens, and P. badia were significantly larger in metal-treated microcosms than in controls. Logistic regression indicated survival in metal-dosed microcosms was less for small individuals than for larger individuals of the same species. These results suggest that some insect species from high-altitude streams were smaller than those from low-altitude streams, and that survival was greater for larger lifestages. Thus the variation in response of macroinvertebrates between different altitude streams observed in earlier studies may be due to differences in body size. The effects of low levels of metals (half the chronic levels of Cd, Cu, and Zn) on some species varied in relation to invertebrate density (low and high density) and invertebrate predation (no predators added and predators added). The abundance of Hydropsyche sp. was significantly lower in metal-dosed, high density treatments than in control, high density treatments. Moreover, the effects of an invertebrate predator (Hesperoperla pacifica) on Hydropsyche sp. was significantly greater in metal-dosed microcosms than in controls. These results suggest that metals interact with biotic factors to influence stream invertebrate community structure, and that effects occurred at metal concentrations lower than chronic criteria value. Toxicity experiments in stream microcosms showed that the abundance and species richness of aquatic insects were significantly reduced at 1x, 5x and 10x the United States Environmental Protection Agency chronic levels of cadmium, copper, and zinc (1x=1.1, 5.0, and 110 μg/L Cd, Cu, and Zn, respectively). Mayflies were the most sensitive group, as the abundance of Baetis sp. and Rithrogena hageni were significantly reduced in the Ix treatment. The response of Drunella grandis was size dependent, as small lifestages were significantly more sensitive than large lifestages. Stoneflies were also affected, but their response was more variable with abundances of some species (Pteronarcella badia) being reduced in the Ix treatment, whereas other species were unaffected (Sweltsa sp.). Heptageniid mayflies were consistently less abundant downstream of sources of metal contamination in the Arkansas and Eagle rivers, whereas the response of other measures were more variable. For instance, species richness and total density were greater at a metal-contaminated site on the Arkansas River compared with an upstream reference site. Therefore, results from this experiment and field survey suggest that changes in abundance of heptageniid mayflies may provide a reliable indicator of metal-contamination in western streams.
Open Access
Implications of movement behavior responses of both Asian and African elephants in changing landscapes of the 21st century
(Colorado State University. Libraries, 2023) Chan, Aung Nyein, author; Wittemyer, George, advisor; Leimgruber, Peter, committee member; Noon, Barry, committee member; Aldridge, Cameron, committee member
An organism moves to fulfil its most fundamental survival and reproductive needs. Studying movement behavior can provide insights into both inter- and intra-specific interactions, how a species interacts with its environment and accesses resources, species distribution, etc. Given human presence affects mammalian movement across the globe, animal movement studies are increasingly important to assess and understand the impacts of humans on wildlife. Movement behavior response to human presence is particularly relevant and important to understand in the 21st century since global human population is projected to reach 9.7 billion by the year 2050. The unprecedented level of human presence and associated land use changes will impact all living organisms on the planet, particularly megaherbivores such as Asian and African elephants which have some of the largest space use requirements among terrestrial mammals. My dissertation research focuses on studying and understanding the movement behavior responses of Asian and African elephants to human-related landscape changes. The Asian elephant (Elephas maximus) which is currently listed as endangered under the IUCN red list of threatened species. The population status of the species is unclear but declining. The species is facing habitat loss and fragmentation due to agricultural expansion, heightened human-elephant conflicts related to human encroachment in previous wilderness areas, and illegal killings, including but not limited to, poaching for skin, ivory, and meat. The largest remaining tracts of wildland (i.e., habitat suitable for wild elephant to exist) among the current extant range countries/states occurs in the country of Myanmar. However, the struggling economy and unstable political climate put unusual amount of stress on the remaining elephant populations across the country. Asian elephant numbers are declining across much of their range in Myanmar, driven largely by serious threats from land use change resulting in habitat loss and fragmentation. To effectively manage and conserve the remaining populations of endangered elephants in the country, it is crucial to understand their movement behavior across the country's agricultural gradient. Chapter 1 provided baseline information on elephant spatial requirements and the factors affecting them in Myanmar. This information is important for advancing future land-use planning that considers space-use requirements for elephants. Failing to do so may further endanger already declining elephant populations in Myanmar and across the species' range. We used autocorrelated kernel density estimator (AKDE) based on a continuous-time movement modeling (ctmm) framework to estimate dry season (26 ranges from 22 different individuals), wet season (12 ranges from 10 different individuals), and annual range sizes (8 individuals), and reported the 95%, 50% AKDE, and 95% Minimum Convex Polygon (MCP) range sizes. We assessed how landscape characteristics influenced range size based on a broad array of 48 landscape metrics characterizing aspects of vegetation, water, and human features and their juxtaposition in the study areas. To identify the most relevant landscape metrics and simplify our candidate set of informative metrics, we relied on exploratory factor analysis and Spearman's rank correlation coefficients. Based on this analysis we adopted a final set of metrics into our regression analysis. In a multiple regression framework, we developed candidate models to explain the variation in AKDE dry season range sizes based on the previously identified, salient metrics of landscape composition. Our objectives were to (1) estimate the sizes of dry, wet, and annual ranges of wild elephants in Myanmar; and quantify the relationship between dry season (the period when human-elephant interactions are the most likely to occur) range size and configurations of agriculture and natural vegetation within the range, and (2) evaluate how percentage of agriculture within dry core range (50% AKDE range) of elephants relates to their daily distance traveled. Elephant dry season ranges were highly variable, averaging 792.0 km2 and 184.2 km2 for the 95% and 50% AKDE home ranges, respectively. We found both the shape and spatial configuration of agriculture and natural vegetation patches within an individual elephant's range play a significant role in determining the size of its range. We also found that elephants are moving more (larger energy expenditure) in ranges with higher percentages of agricultural area. Chapter 2 reveals how elephants interact with agriculture and other important environmental variables such as natural vegetation, roads, and water, etc. Habitat loss and fragmentation due to accelerated agriculture expansion is a major threat to existing wildlife populations across Asia. Although it had been shown that Asian elephant space use was correlated with the level of fragmentation on the landscape in Chapter 1, the mechanism underlying this process is not well documented and can serve to help focus conservation efforts. We analyzed selection behavior of wild elephants across three study sites with different levels of agriculture use patterns in Myanmar, assessing the impact of structure in the agriculture- wildlands interface on habitat selection by elephants. Given elephants exhibit heterogeneous spatial behavior, we fitted two types of selection models to gain insight into the diversity of strategies employed at the local- and home-range scale. We used variance partitioning analysis to quantify the explanatory contribution of individual, study site, and sex. We found that the variation in the resource selection behavior was mainly due to individual differences, and the level of agriculture present in an individual's range was the most influential to its selection behavior. Gaining a deeper understanding of habitat selection behavior by elephants across the changing landscapes of Asia can help inform management decisions and conservation actions. As the military coup in 2021 in Myanmar affected my ability to continue working in Myanmar, we decided to transition into assessing the connectivity between Etosha National Park and an adjacent Kunene multi-use conservancies area in Namibia for African elephant (Loxodonta africana) as Chapter 3. This region is of particular importance in African elephant conservation since the population is doing relatively well in the area and could serve as one of the remaining strongholds for the species. The loss of habitat and fragmentation of landscapes could lead to declines in wildlife populations, highlighting the need to identify and preserve critical habitats. Connectivity between populations plays a crucial role in mitigating the risks faced by small populations and ensuring their long-term persistence. As a result, the identification of corridors has become a key objective in wildlife conservation. Various methods have been developed to identify high connectivity locations, including resistance surface modeling and empirical-based approaches using GPS tracking data. We used GPS telemetry data from 66 elephants to empirically quantify connectivity using a graph-theoretic approach and assessed landscape features influencing connectivity. We applied the 'movescape' approach to define and locate different types of corridors and examined how landscape features differed across these corridors. Our results revealed strong variation in connectivity across the landscape, with paths of high connectivity near water sources between the study areas. We found that factors related to water sources and human presence primarily influenced connectivity. The findings of this study provide valuable insights into the connectivity patterns and landscape features influencing connectivity for African elephants in northwestern Namibia. We discussed this findings in the context of future conservation management scenarios. Finally, Chapter 4 assessed the current knowledge on population status of Asian elephants across all 13 range countries or states. We conducted a literature search on Google Scholar using keywords, "Asian elephants", "Population size", "Abundance", and "Density". We found 26 articles and 9 governmental and non-governmental reports from 2000 to 2022 to evaluate the extent of population assessments using statistically robust methods. Our findings indicate that only 4.39% of the current known distribution of Asian elephants had been assessed using robust sampling and statistical approaches. Out of the 13 range states, only 7 had conducted assessments, with only 3 countries performing robust population assessments in the last 5 years. We highlight the urgent need for more comprehensive and up-to-date studies to accurately estimate the population size of Asian elephants. We recommend investing in spatial capture- recapture approaches using fecal-DNA and photographic capture-recapture methods where feasible to improve abundance estimation. The results of this review emphasize the critical role of accurate population knowledge for effective conservation and management actions for endangered species like the Asian elephant. This dissertation provides critical pieces of information regarding movement ecology and conservation of both Asian elephant and African elephant. We present analyses on space use requirements, resource selection behavior and the quantification of sources of variation in the movement behavior for Asian elephant in Myanmar. Chapter 1 and chapter 2 were the first two studies to assess movement behavior in Myanmar using empirical data. Since identifying and conserving corridors is one of the key objectives for African elephant's conservation, chapter 3 provides crucial information for managers on the ground in Etosha National Park and surrounding areas. Finally, we highlighted the research gap in Asian elephant conservation by reviewing studies and reports on population status across the species' range.
Open Access
Breeding waterfowl productivity in a flood-irrigated agricultural landscape
(Colorado State University. Libraries, 2023) Setash, Casey M., author; Koons, David N., advisor; Pejchar, Liba, committee member; Gammonley, James H., committee member; Sueltenfuss, Jeremy P., committee member
Similar to agricultural production, the sustainable management of waterfowl populations across the western United States inherently depends on limited water availability. Both endeavors are increasingly challenged by municipal demands for water, drought, and changes in the seasonality of precipitation. Healthy wetlands for wildlife can be sustained in conjunction with the needs of agricultural producers on working lands, but the multifaceted importance of water management is rarely quantified. Information pertaining to the multiple benefits of water management practices might bring to light the larger societal importance of sound water management. This may allow natural resource managers to allocate resources more efficiently and effectively by directing them towards the practices with demonstrated advantages for both wildlife and agricultural producers. The North Platte Basin in north-central Colorado (hereafter North Park) is a model system to evaluate benefits and trade-offs of hydrological manipulations that benefit both agricultural producers and fish and wildlife. Not only are waterfowl and water management already being conducted by federal and state agencies and NGOs like Ducks Unlimited, but North Park is also representative of many working lands throughout the Intermountain West. Agricultural producers in North Park flood irrigate rather than using center-pivot irrigation, which strongly affects on hydrological regimes, water tables, wetlands, and stream flows. Flood irrigation more closely resembles natural stream and river flood regimes and is thought to be more beneficial for wildlife, water table recharge, and evaporative cooling of return flow water. As water resources become diverted for urban municipal uses and the increasing frequency of drought reduces water availability in the semi-arid West, it is believed that the North Platte Basin may begin to play a significant role in the production of waterfowl on a statewide or even a flyway scale. As private land becomes an increasingly important component of waterfowl habitat and water resources become limiting, a strong foundational knowledge regarding how flood-irrigated systems impact wetland-dependent species will therefore be imperative to properly manage waterfowl populations in coordination with agricultural production. We first sought to evaluate the efficacy of flood-irrigated agricultural lands as nesting habitat for breeding waterfowl in the context of land-use intensity. The debate over the best agricultural practices for biological conservation typically focuses on land sharing and land sparing production strategies. One end of the spectrum posits that high-intensity agriculture and the smaller footprint associated with it allows for other land parcels to be spared for biodiversity and therefore provides more suitable habitat, whereas others argue that agricultural lands should be cultivated at a low intensity and interspersed with wildlife habitat, therefore sharing the land with wildlife. We evaluated the demographic consequences of land-sharing and land-sparing practices on breeding bird nest site selection and nest survival, focusing specifically on waterfowl in a flood-irrigated hay agricultural system. We specifically assessed the habitat features related to both shared and spared lands driving nest site selection at two scales and how those same features scaled up to impact nest survival. Nests were located disproportionately closer to uncut irrigated meadows and farther from harvested hay meadows relative to available points, but closer to irrigation ditches. Nests closer to irrigation ditches, uncut irrigated meadows, and open water also experienced higher nest survival. This system is representative of many agricultural systems around the globe and illustrates the ways agricultural practices can shape habitat selection have reproductive consequences for wildlife. After evaluating the importance of wetlands associated with flood irrigation for nesting, we focused our efforts on elucidating their contributions as foraging habitat. Food availability varies considerably over space and time in wetland systems, and consumers must be able to track those changes during energetically-expensive events like breeding. Resource tracking has been studied frequently among herbivores, but rarely receives attention among consumers of macroinvertebrates. We evaluated the change in resource energy density across habitat types and time, and the ability of waterfowl to track macroinvertebrate resources across wetland types and over the course of the breeding season in a high-elevation, flood-irrigated system. We also assessed whether the density of energy resulting from macroinvertebrates explained more of the variation in waterfowl abundance across habitats, or whether the consistency (i.e., temporal evenness) of the resource played a larger role using a pseudo-R2 metric. Energy density varied widely across wetland types, but was highest in basin wetlands (i.e., ponds) and was higher in wetlands with higher temperatures, specific conductivity, and lower dissolved oxygen. Both breeding pair abundance and duckling abundance were positively associated with energy density and resource consistency (R2 = 0.06 for pair abundance and 0.31 for duckling abundance), but energy density explained more of the variation in both waterfowl responses (R2 = 0.77 for pair abundance and 0.58 for duckling abundance). These results have the potential to not only elucidate mechanisms of habitat selection among waterfowl, but also indicate where and when water resources should be allocated as climate conditions become increasingly arid. The technological tools we used initially to evaluate waterfowl use of flood-irrigated habitats (i.e., Global Positioning System [GPS] tags) have become a common tool in ecological studies of animal behavior and demography despite previous research indicating negative impacts on vital rates across a variety of taxa. We therefore focused next on evaluating the impacts of GPS tags on our focal waterfowl species and others across the life-history spectrum. Researchers face tradeoffs when deciding whether they are an appropriate tool because GPS tags may impact vital rates, but they provide detailed data on movements and behavior that often cannot be obtained in other ways. Using band recovery data from hunter harvests, we evaluated the strength of effects induced by GPS tags on annual mortality of adult females across 13 waterfowl species, and whether species with a slower life-history strategy might be more resilient to GPS tag effects than their fast-lived counterparts. Hazard ratios, indicating the risk of death for individuals wearing GPS tags compared to those wearing only metal bands, ranged from 0.92 - 4.38 and the mean difference in survival between marker types across species was 0.31, but these results are averaged across the study period. The magnitude of tag effects remained constant across life-history tempo, indicating that slower-lived species were not able to buffer the effect of wearing GPS tags. When scaling effect sizes up to a currency of fitness, slower-lived species exhibited a similar handicap of wearing GPS tags compared to species with a faster life-history strategy, and the effects were notable. Our results highlight that even small impacts to important vital rates can affect inference pertaining to survival and mortality as well as fitness from birds affixed with GPS tags. The results of this study revealed considerable survival effects across species, although time trends illustrated decreasing effect sizes for most species over time. Results emphasize the importance of testing for such effects in future research as technology advances. Finally, we used components of each previous chapter to characterize the population of breeding ducks in this system and the demographic consequences of environmental conditions. Waterfowl populations in the Intermountain West rely upon water availability and are not as frequently studied as populations within North American core breeding areas like the Prairie Pothole Region. Different species experience different environmental conditions during peak nest initiation depending on their breeding phenology, especially in variable environments like those associated with high-elevation systems. We fit species-specific integrated population models to evaluate the demographic drivers of mallard and gadwall populations breeding in a high-elevation intermountain basin in Colorado representative of many Intermountain West habitats from 2018-2022. Each species initiated nests at opposite ends of the phenological spectrum, allowing us to assess the effects of environmental conditions on demography. Both mallard and gadwall annual after-hatch-year (AHY) female survival probabilities were comparable to estimates from other regions (hatch-year [HY] mallards = 0.48 [SD = 0.09] to 0.53 [SD = 0.07], AHY mallards = 0.53 [SD = 0.07] to 0.57 [SD = 0.05], HY gadwall = 0.44 [SD = 0.13] to 0.52 [SD = 0.14], AHY gadwall = 0.56 [SD = 0.11] to 0. 66 [SD = 0.12]). Annual recruitment, a metric of the number of females produced per breeding pair, was similar among gadwall (0.62 [SD = 0.80] to 1.04 [SD = 1.04]) and mallards (0.40 [SD = 0.48] to 1.59 [SD = 0.95]), but realized population growth rate (λ) did not vary as much for gadwall (0.93 [SD = 0.56] to 1.21 [SD = 0.59]) as it did for mallards (0.76 [SD = 0.24] to 1.55 [SD = 0.24]). Recruitment of both species exhibited quadratic relationships with spring growing degree days, indicating recruitment was higher during springs with intermediate temperatures, and spring snow-water equivalent metrics in the surrounding mountains positively impacted HY and AHY mallard survival in addition to HY gadwall survival. The results of this study emphasize the need for continued monitoring of waterfowl outside of traditional survey areas and provide insight into water management strategies to target important vital rates as climate and land use change.
Open Access
Forest elephants modulate their behavior to adapt to sounds of danger
(Colorado State University. Libraries, 2023) Verahrami, Anahita K., author; Bombaci, Sara, advisor; Blanchard, Nathaniel, committee member; Wittemyer, George, committee member
The African forest elephant (Loxodonta cyclotis) plays a critical role in upholding the structure and function of the Congo Basin, the world's second largest tropical forest which crucially contributes to global carbon sequestration. Research has demonstrated an 86% decline in forest elephant population numbers between 1990-2021, largely because of hunting for ivory. Due to the species' cryptic nature in their dense rainforest habitat, little is known on how they respond to human disturbances such as gun hunting. The studies that have been completed reveal that forest elephants may respond to disturbance by demonstrating changes in their abundance, distribution, and nocturnal activity. Changes in forest elephant distribution and activity not only have ramifications for the species' activity budgets, which when affected, may influence their foraging and reproductive behaviors and success, but may also impact the species' interspecific interactions with vegetation in certain areas, affecting forest growth and function. However, little is known on how a key population of this critically endangered species in the northern Republic of Congo is responding to disturbance such as hunting in the region. Using acoustic detection models in combination with a landscape-scale acoustic monitoring effort in and around Nouabalé-Ndoki National Park, Republic of Congo, I assess how forest elephant vocal activity is being influenced by gun hunting. Using these data, I examine (1) how forest elephant vocal activity changes across an eight-day period and (2) if forest elephants are shifting to more nighttime vocal activity following a gun hunting event. Results show that, on average, forest elephants are present and vocal at sites without gun events 53% of the time, but at sites with gun events, this value drops to 43%. Results also indicate that this change in activity following a gun hunting event is sustained over the eight-day period examined and does not vary from day-to-day. Results from the analysis exploring how the proportion of nighttime calling activity changes in response to gun hunting show that number of gunshots is an important predictor of nighttime vocal activity. Specifically, as the number of gunshots increase, there is a dramatic increase in the proportion of nighttime calling activity. Understanding the degree at which forest elephants are affected by gun hunting provides a convincing argument to focus limited conservation resources on developing more effective strategies to reduce indirect impacts from hunting on this critically endangered and ecologically important species.
Open Access
The bighorn sheep of Battlement Mesa - a low elevation population
(Colorado State University. Libraries, 1991) Cunningham, Mary Louise, author; Bailey, James A., advisor; Alldredge, A. William, committee member; Lehner, Philip N., committee member
I studied bighorn sheep on Battlement Mesa, Colorado, from 12/88 to 7/90, to determine present and past herd status and distribution, so that 1) management options are clarified and 2) future management activities may be evaluated. I studied the herd by tracking 1 radio-collared ewe and obtaining visual observations and by systematically sampling study area units for sheep, sheep sign, potential competitors, potential predators and sheep carcasses. I recorded water sources that were encountered. I developed an historic perspective of the herd by searching agency files and local newspapers and interviewing local residents. The herd numbered up to 200-250 animals in the early 1900s and declined to an estimated 50 animals by 1970. Minimum herd sizes during 1989 and 1990 were 23 and 26, including lambs, respectively. Since 1961, the herd has abandoned approximately 56 km2 of historic range in the Mamm Peaks area. The herd decline corresponded with probable vegetation changes on Battlement Mesa, intensive livestock grazing through the 1950s, reports of poaching and an increasing elk herd. Sheep remained on the western portion of the range during winter and spring, 1989. Ewe/juvenile groups migrated to Anderson and Durant Gulches between 5/15-7/15/89 for lambing. Rams were more dispersed and in groups of 1-3, except during the rutting season. Ewe/juvenile group size ranged from 1-13. During dry months, (7/89, 8/89, 6/90) sheep concentrated in Anderson and Durant Gulches where a free-flowing spring and a seep were located. Bighorn sheep on Battlement Mesa appear limited by dense mountain shrub stands which separate all productive meadows from escape terrain and cover historic migration routes. A significantly greater use of the shale slope habitat contributed most to rejecting the null hypothesis that sheep use habitat types in proportion to their availabilities on Battlement Mesa. Sheep remained on shale slopes most (75% of all observations) of the time, using scattered grasses, forbs and shrubs for forage and seeps for water. Intensive and long term habitat management for bighorn sheep on Battlement Mesa is required. I suggest a 4-phase management program to improve existing range and later to reestablish and maintain historic migration corridors to productive historic summer range. Without management to improve existing conditions, this small, unique herd will remain static or decline.
Open Access
Demographic consequences of agricultural practices on a long-lived avian predator
(Colorado State University. Libraries, 2022) Vennum, Christopher Ryan, author; Koons, David N., advisor; Pejchar, Liba, committee member; Kendall, Bill, committee member; Boone, Randall, committee member
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