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Environmental Factors, Not Plants, Contribute To Functional Diversity Of Soil Bacteria In The Dunes Of Lake Michigan., Andrea Stark Howes

Electronic Theses and Dissertations

Soil bacteria play important roles in nutrient cycling and other ecosystem functions, and many biotic and abiotic factors can influence bacterial functional diversity. The goal of this field study was to examine differences among bacterial communities in sand dunes of Lake Michigan. I used Biolog Ecoplates™ to compare bacteria functional diversity associated with four different plant species: the native dune-building grass Ammophila breviligulata, invasive species Leymus arenarius and Gypsophila paniculata, and native legume Lathyrus japonicus across 13 sites in Michigan, representing a gradient in abiotic factors such as precipitation and temperature. I found no differences in bacterial function associated with …

Heterogeneity Of Avian Breeding Habitat On Grazing Lands Of The Northern Great Plains, Maggi S. Sliwinski

School of Natural Resources: Dissertations, Theses, and Student Research

Native rangelands in the Great Plains are largely privately owned and used for beef production. Vegetation heterogeneity is important for maintaining biodiversity, but private land may be more homogenous than desired. My research had two components: 1) to examine whether a variety of grazing strategies created vegetation heterogeneity in a large, intact rangeland, and 2) to understand beef producers’ attitudes about vegetation heterogeneity.

First, I sampled vegetation structure, composition, and bird abundance at multiple plots on eleven management units in Cherry County, Nebraska. Units were managed with commonly used grazing strategies (e.g., short-duration grazing and season-long continuous grazing). I examined …

The Effect Of Boat Type On Bottlenose Dolphin (Tursiops Trucatus) Behavior In The Mississippi Sound, Maria Zapetis

Master's Theses

Increases in oceanic shipping are a global phenomenon, and a leading cause of concern for marine animal welfare. While it may be difficult to assess the effect of boat traffic on all species in all contexts, it is vital to report anthropogenic impacts where longitudinal data is available, and doubly so where a dearth of information exists. The purpose of this study is to describe how dolphin behavior changed in the presence of boats in the Mississippi Sound between 2006 and 2012, and more specifically, to detail how different boat types impacted dolphins’ behavioral states. This study is unique in …

Effects Of Temperature Gradient, Substrate Composition, And Canopy Cover On The Spatial Distribution Of Topminnow Species: Fundulus Notatus And Fundulus Olivaceus, Austin M. King

Honors Theses

Hybrid zones are locations where two interbreeding species coexist and hybridize. The spatial distribution of ecologically similar species is of primary interest in understanding the formation and stability of hybrid zones. These hybrid zones are of significance as they allow for insight into how speciation occurs naturally within the environment. A variety of factors may play a role in determining the spatial distributions of species within hybrid zones. Examples of these factors include variations in temperature gradients, substrate composition, and changes in canopy cover. Fundulus olivaceus and Fundulus notatus are generally found within upstream and downstream habitats respectfully. These habitats …

Range-Wide Prevalence And Impacts Of Pseudocercosporella Inconspicua On Lilium Grayi And An Assessment Of L. Superbum And L. Michauxii As Reservoirs, Cindy L. Barrett

Electronic Theses and Dissertations

Lilium grayi (Gray’s Lily), a southern Appalachian endemic species, is threatened by a Lilium-specific fungal pathogen, Pseudocercosporella inconspicua. The disease is characterized by tan lesions that can cause early senescence, while also lowering seed production and viability. This project tested for P. inconspicua conidia and accessed health at nine locations. The disease was present and ubiquitous across the range of L. grayi. Through identification of P. inconspicua conidia in the field, L. superbum (Turk’s Cap Lily) was identified as an additional host, while L. michauxii (Michaux’s Lily) was disease-free. However, infection was inducible in both species. With …

Niche Modeling For The Giant Panda, Ailuropoda Melanoleuca, And The Original Panda, Ailurus Fulgens: Habitat Preferences And Evolutionary Consequences, Lauren M. Lyon

Electronic Theses and Dissertations

The well-known symbol for conservation, the giant panda bear, and the original red panda have been forced into remote habitats due to anthropogenic disturbance, making ecological study difficult. Therefore the first known species distribution model was created to predict the most likely areas of occurrence within the known range of these elusive animals. These models were then projected onto North America and evaluated against existing breeding programs. Additionally, the close proximity of the Gray Fossil Site and the discovery of the most complete fossil red panda specimens in the world allowed ecomorphological comparisons between the modern red panda, Ailurus fulgens …

Cranial Morphological Distinctiveness Between Ursus Arctos And U. Americanus, Benjamin James Hillesheim

Electronic Theses and Dissertations

Despite being separated by millions of years of evolution, black bears (Ursus americanus) and brown bears (Ursus arctos) can be difficult to distinguish based on skeletal and dental material alone. Complicating matters, some Late Pleistocene U. americanus are significantly larger in size than their modern relatives, obscuring the identification of the two bears. In the past, fossil bears have been identified based on differences in dental morphology or size. This study used geometric morphometrics to look at overall differences in cranial shape and used step-wise discriminant analysis to identify specific characters that distinguish cranial morphology between …

Behavioral Plasticity Across Non-Social Contexts In Female Green Swordtails, Xiphophorus Helleri, Lindsey M. Coit

School of Biological Sciences: Dissertations, Theses, and Student Research

Phenotypic plasticity is the ability of an individual to alter its phenotype in response to environmental change. Individuals that express plasticity in behavior can quickly respond to changes that occur in the environment. Therefore, individuals that exhibit behavioral plasticity can alter their behavioral expression to best match current environmental conditions. The degree and direction of behavioral plasticity may be influenced by variation in individual characteristics. Understanding how variation in individual traits affects behavioral plasticity, and, whether patterns of behavioral plasticity are consistent across behavioral contexts are important topics to explore as we try to better understand how plasticity evolves and …

Ecological Consequences Of Water Loss Under Climate Change In Small Ectotherms, Eric Alexander Riddell

All Dissertations

Warming climates threaten to reduce biodiversity across the planet, yet the capacity of organisms to minimize the effects of climate change are rarely considered in current ecological predictions of climate change. Organisms can minimize the effect of warming through behavioral, physiological, and morphological processes that limit exposure to lethal conditions or improve performance. Therefore, integrating these mechanisms into ecological models might improve predictions on the loss of biodiversity under climate change. For my dissertation, I focus on the physiological processes that influence habitat suitability in a group of terrestrial, lungless salamanders (Plethodon spp.) found in the core of the global …

Living On The Edge: Assessing The Effects Of Catastrophic Fire On Plants Utilized By Two Endemic Subspecies Of Spring Mountains Butterflies, Charles Ryan Herrmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

In the past few decades there has been an increase in catastrophic, high-intensity, large-scale wildfires globally due to the combination of climate warming with more than a century of fire suppression policy. One region that has been drastically affected is the Western United States, as there has been an increase in ‘mega-fires’ in the past few decades. The 2013 Carpenter 1 Fire in the Spring Mountains, Nevada was the largest fire in recorded history in these mountains, spreading out over 11,137 hectares. Catastrophic fire like the Carpenter 1 Fire can have potentially devastating effects on endemic species inhabiting refugia on …

Behavioral Paleoecology Of Lower Cambrian Deposit Foragers: Reinterpreting Looping And Meandering Traces Using Optimal Foraging Theory And Quantitative Analysis, Zachary Andrew Jensen

UNLV Theses, Dissertations, Professional Papers, and Capstones

The early Cambrian was a period of transition during which the seafloor environment was changing from a microbial-mat-dominated environment to a bioturbation-dominated environment. The result was a patchy landscape of variable food resources for foraging burrowers to exploit. Looping trace fossils, such Psammichnites gigas and Taphrhelminthopsis nelsoni, appear in strata worldwide during this transitional period, and the ecological niche they filled is a subject of debate among ichnologists. The objectives of this study are (1) to determine the foraging strategies preserved by looping traces through the application of optimal foraging theory and quantitative analysis, and (2) use those results to …

Replicability And Reproducibility In Comparative Psychology, Jeffrey R. Stevens

Jeffrey Stevens Publications

Psychology faces a replication crisis. The Reproducibility Project: Psychology sought to replicate the effects of 100 psychology studies. Though 97% of the original studies produced statistically significant results, only 36% of the replication studies did so (Open Science Collaboration, 2015). This inability to replicate previously published results, however, is not limited to psychology (Ioannidis, 2005). Replication projects in medicine (Prinz et al., 2011) and behavioral economics (Camerer et al., 2016) resulted in replication rates of 25 and 61%, respectively, and analyses in genetics (Munafò, 2009) and neuroscience (Button et al., 2013) question the validity of studies in those fields. Science, …

Spring Field Report, March-May 2017, W. Ross Silcock

Nebraska Bird Review

In general, this was a routine spring, except for remarkable numbers reported of several species, and a notable paucity of most species of wood-warblers. A huge Snow Goose flock in the east was estimated to contain 500,000- 1,000,000 birds; other notable numbers were 2000 Tree Swallows and 5000 Cliff Swallows, both record counts, 44 Black-capped Chickadees, 300 House Wrens, 62 Fox and 76 Song Sparrows on the same day at a single location, 168 Dark-eyed (Slate-colored) Juncos, and 10,000 Common Grackles. Perhaps the most notable phenomenon this spring was the dearth of migrant wood-warblers. Joel Jorgensen constructed graphics based on …

Influence Of Stream Permanence, Predation, And Invasive Species On Crayfish In The Ozark Highlands With An Emphasis On Species Of Greatest Conservation Need (Orconectes Marchandi, Orconectes Eupunctus And Cambarus Hubbsi), Allyson Noelle Yarra

Graduate Theses and Dissertations

Due to the ecological importance of crayfish and the increasing vulnerability of freshwater systems due to habitat loss, invasive species, and hydrologic alteration, understanding crayfish-environment relationships is crucial in the context of aquatic species conservation. I sought to examine the influence of hydrologic variation among intermittent and permanent streams on crayfish occupancy, abundance, predation risk, and potential vulnerability to invasive species effects. I conducted crayfish and environmental data sampling during two consecutive summers across 20 Ozark streams of differing permanence levels (10 intermittent, 10 permanent). In these same streams, I conducted fish and scat surveys over the course of four …

Flight Activity, Oviposition Pit Distribution, And Emergence Densities Of Monochamus Titillator And M. Carolinensis In The Ozark-St. Francis National Forest In Arkansas, Jake Bodart

Graduate Theses and Dissertations

Monochamus (Coleoptera: Cerambycidae) are a genus of longhorn beetles commonly known as pine sawyers. They have a worldwide distribution coincident with pines (Pinaceae) and are vectors of the pinewood nematode (Bursaphelenchus xylophilus). In the United States, there are eight known Monochamus species and they have a sympatric distribution with at least one other Monochamus species throughout their range. Monochamus are known to attack stressed, dead, and dying conifers especially pines. In the Ozark- St. Francis National Forest in Arkansas, there are two species of pine sawyers and they share this sympatric distribution observed throughout the United States, M. titillator (southern …

Where In The World Are Pallas's Fish Eagles? Migration And Ecology Of Haliaeetus Leucoryphus In Asia, Marla Lynn Steele

Graduate Theses and Dissertations

Pallas’s Fish Eagle (Haliaeetus leucoryphus) is the Northern Hemisphere’s least understood eagle species. Virtually nothing is known concerning the species’ ecology. Historically, Pallas’s Fish Eagles were expected to breed in three separate populations in Mongolia, China, and India and was considered one of the most common raptors in Asia prior to the 1900’s. However, by 1960’s major declines were observed. The species is currently listed as “globally vulnerable” by the International Union for the Conservation of Nature (IUCN) Red List. The current study examined over a century of Pallas’s Fish Eagle observation data to determine occupancy and detection rates throughout …

Phenology, Habitat Use, And The Impacts Of Wetland Management On Autumn Migrating Rails In Missouri, Auriel M.V. Fournier

Graduate Theses and Dissertations

Rails (Family: Rallidae) are among the least studied birds in North America, in large part due to their elusive nature. As a wetland-dependent species, understanding the timing of their migration and their habitat needs during migration is especially important since management needs to be timed to balance the needs of many species. I developed and verified a new distance sampling based nocturnal ATV spotlight survey because traditional call-broadcast surveys are not effective during autumn migration because of the drop off in call rate after the breeding season. These surveys allow us to ask point-level questions about what habitats rails select …

Plant-Microbial Interactions Are Strong Determinants Of Plant Population And Community Dynamics, Yan-Yi Anny Chung 9485698

Biology ETDs

Plant-microbial interactions are ubiquitous and yet the consequences of these interactions on plant population and community dynamics are relatively unknown. Here, we used two different classes of plant-microbial interactions to examine their effects on key plant population and community characteristics such as commonness and rarity, competition and coexistence, as well as community stability.

Vertically-transmitted endophytes had stage-dependent effects on the population growth of two grass species Poa sylvestris and Poa alsodes, and generally increased host population growth rates. However, it was the intrinsic demographic advantage of P. sylvestris that allowed its population to grow at a much faster rate …

The Influence Of Aspen Chemistry And The Nutritional Context On Aspen Herbivory, Kristen Y. Heroy

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Consumption of aspen by herbivores is one major force causing aspen decline in North America. In this Dissertation, I aimed to determine why herbivores prefer browsing on certain aspen stands over others, and why they prefer consuming aspen that contains chemical defenses over understory forages like grasses, forbs, and shrubs. I explored the influence of nutrients and chemical defenses within aspen on aspen intake and preference by lambs in pen experiments. I also explored drivers of aspen preference on the landscape by looking at relationships between aspen herbivory, indicators of aspen health, amount of nutrients available in the understory, and …

Direct And Indirect Effects Of Climate Change On Plant Populations And Communities In Sagebrush Steppe, Andrew R. Kleinhesselink

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Rapid climate change presents humanity with a number of big problems. Foremost among these is the sad fact that the climate we will pass on to our children will likely be nothing like the climate that we inherited from our parents. Ecologists have collected solid evidence that climate change has already begun to affect the living things around us and the ecosystems humans depend on. Unfortunately, predicting the future effects of climate change on life on earth is not easy. We focused on three research goals as part of an effort to improve our ability to predict how plants and …

Effects Of Variable And Changing Environments On Demography: Inferences From A Lesser Snow Goose Colony, David T. Iles

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The mean and variability of environmental conditions have changed as a result of human activity, and continued changes are predicted. The strongest effects on natural populations will often be channeled through species interactions, as shifts in species range limits and life cycle schedules will shift in relation to each other. These changes will often impact rates of survival, growth, and reproduction simultaneously, and these effects will likely differ across habitats.

In chapter 2, I used mathematical modeling and computer simulations to investigate the evolutionary significance of increasingly variable environments, and examine how evolutionary pressures change when multiple vital rates are …

The Behavior And Ecology Of Cursorial Predators And Dangerous Prey: Integrating Behavioral Mechanisms With Population-Level Patterns In Large Mammal Systems, Aimee Tallian

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Driving into Yellowstone National Park for the first time is a moving experience. Gazing over the sweeping landscapes, seeing a geyser erupt 80 feet into the air, and having your first ‘wildlife encounter’, whether that be a 2 ton bull bison aggressively wallowing on his dirt mound, snorting and kicking up dust, or watching a pack of 6 wolves move through a valley off in the distance, pausing to howl in search of their companions. Yellowstone staff wishes to manage our park in a way that preserves these remarkable experiences. In order to effectively manage this dynamic ecosystem, it is …

Spatial Ecology Of Coyotes And Cougars: Understanding The Influence Of Multiple Prey On The Spatial Interactions Of Two Predators, Peter J. Mahoney

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The coyote (Canis latrans) has expanded throughout much of North America over the past century following the regional extirpation of apex predators. These highly adaptable canids can occupy a variety of landscapes from the rainforests of Central America to the dense, human-dominated urban centers of the United States. As a generalist predator, coyotes can capitalize on a variety of food resources, including anthropogenic subsidies such as domestic livestock and food tailings at landfills. These tendencies often bring coyotes in direct conflict with humans, forcing managers to consider mitigation strategies ranging from the targeted removal of problem individuals to …

Predicting The Impact Of A Northern Pike (Esox Lucius) Invasion On Endangered June Sucker (Chasmistes Liorus) And Sport Fishes In Utah Lake, Ut, Jamie Reynolds

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Invasive species introductions are associated with negative economic and environmental impacts, including reductions in native species populations. Successful invasive species populations often grow rapidly and a new food web structure is established. The ability of invasive species to outcompete and prey upon native species are two characteristics that make them a leading cause of fish extinctions in North America.

Northern pike (Esox lucius; hereafter pike) are voracious ambush top predators \native to the upper Midwest and Mid-Atlantic regions of the lower 48 United States, Alaska, and southern Canada. Pike have been spreading across the Intermountain West and Pacific …

Spatial And Behavioral Patterns Of Captive Coyotes, Jeffrey T. Schultz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Environmental enrichment is a technique used at many captive animal facilities that can improve the well-being of their animals. It seeks to enhance habitat features and promote natural behavior by providing a variety of practical ways for captive animals to control their environmental settings, especially during stressful circumstances. Enclosure features, such as shelter structures, are one tool that promotes wild behavior by adding complexity to an enclosure’s physical environment. Enrichment efforts for captive wildlife are most effective when they are specialized to the biological needs of the animals. Human activity may alter captive animal behavior and utility of enclosure features, …

First Record Of Myrmarachne Formicaria (De Geer) (Araneae: Salticidae) In Pennsylvania, Lawrence Barringer

Insecta Mundi

Myrmarachne formicaria (De Geer) (Araneae: Salticidae) is reported from Pennsylvania for the first time, new state record. Seventeen specimens were collected in Lindgren funnel and bucket traps during 2016. This connects the two reported ranges of this species in Ohio and New York.

Bruchidae Of Chile (Insecta: Coleoptera), John M. Kingsolver, Juan E. Barriga Tuñón, Jesús Romero Nápoles, Michael C. Thomas

Insecta Mundi

Species descriptions, keys to genera and species, and geographical distributions are presented for 43 species of the family Bruchidae (Coleoptera: Chrysomeloidea) for Chile. Of these species, seven are described as new: Acanthoscelides aricae sp. nov., Lithraeus chillan sp. nov., L. comptus sp. nov., L. elguetai sp. nov., L. limari sp. nov., L. lonquimay sp. nov., and L. penai sp. nov. Eight species are endemic to Chile. A list of true host plants and floral records for those with known host associations is presented. Habitus photographs and drawings of pertinent body parts, including male genitalia, are provided. References pertaining to the …

Psychobiology Of Ingestive Behavior Of Herbivores, Juan J. Villalba

Wildland Resources Faculty Publications

This article describes the process of food selection and consumption in herbivores based on smell, taste, and touch.

Disease Introduction By Aboriginal Humans In North America And The Pleistocene Extinction, Zachary D. Nickell, Matthew D. Moran

Journal of Ecological Anthropology

While overhunting and climate change have been the major hypotheses to explain the late-Pleistocene New World megafaunal extinctions, the role of introduced disease has only received brief attention. Here, we review pre-Columbian diseases endemic to aboriginal Americans and evaluate their potential to cause large-scale mortality in Pleistocene mammals. Of the probable communicable diseases present in pre-Columbian times, we regard anthrax and tuberculosis as viable candidates. These two diseases demonstrate characteristics that could have made them deadly to immunologically naïve populations. Introduced disease, as a primary cause or interacting with overhunting and climate change, could have contributed to the decline and …

Gregariousness Does Not Vary With Geography, Developmental Stage, Or Group Relatedness In Feeding Redheaded Pine Sawfly Larvae, John W. Terbot Ii, Ryan L. Gaynor, Catherine R. Linnen

Biology Faculty Publications

Aggregations are widespread across the animal kingdom, yet the underlying proximate and ultimate causes are still largely unknown. An ideal system to investigate this simple, social behavior is the pine sawfly genus Neodiprion, which is experimentally tractable and exhibits interspecific variation in larval gregariousness. To assess intraspecific variation in this trait, we characterized aggregative tendency within a single widespread species, the redheaded pine sawfly (N. lecontei). To do so, we developed a quantitative assay in which we measured interindividual distances over a 90-min video. This assay revealed minimal behavioral differences: (1) between early-feeding and late-feeding larval instars, …