Ecology and Evolutionary Biology Commons^™

Assessing Intra-Seasonal Changes In Summer Elk Diet Composition, Ava E. Window

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Elk (Cervus canadensis) require adequate forage to fulfill their seasonal nutritional requirements. Elk undergo their highest nutritional demands during summer to support critical life functions such as late gestation, lactation, and juvenile growth. However, variations in plant phenology significantly influence the quality and quantity of forage available to elk during the summer season. As summer advances and plant communities mature, forage quality often declines, leading to a landscape that imposes greater nutritional constraints on elk. As a result, prior research on elk foraging habits has primarily focused on late summer. This has led to limited knowledge surrounding the …

The Prize Biter Of Modernity? Investigating Killer Whale Bite Mechanics, Daniel Hong

West Chester University Graduate Theses, Dissertations, and Final Projects

Although the killer whale (Orcinus orca) is a cosmopolitan apex predator, very little work has been done on its feeding biomechanics. Here I use finite element analysis to investigate the mandibular stiffness of a juvenile male Bigg’s killer whale, and compare it to that of the false killer whale (Pseudorca crassidens) and the saltwater crocodile (Crocodylus porosus). Full mandibles and left and right halves of mandibles are simulated under FEA. I also estimate the total jaw muscle force produced by the Bigg’s killer whale using the dry skull method. The killer whale lacks an …

Habitat Loss And Its Behavioral Effects On A Female Gray Hawk In The Lower Rio Grande Valley Of Texas, Usa, Michael T. Stewart, Ashley M. Tanner, Brian A. Millsap, William S. Clark

Human–Wildlife Interactions

Habitat loss is a major threat to wildlife worldwide. While habitat loss is commonly associated with the fragmentation, degradation, or destruction of large tracts of suitable space, habitat loss in urban environments can be much more incremental and nuanced. We tracked an adult female gray hawk (Buteo plagiatus) in the Lower Rio Grande Valley of Texas, USA, before and after 70% of the trees (7.6 ha) were cleared from the core of the nesting territory. While the hawk’s overall activity budget between within-patch and exploratory movements was unchanged, the hawk undertook substantially longer exploratory movements after the trees …

Linking Disturbance & Macrophyte Colonization–Extinction Dynamics To Invasion Success & Community Assembly: Integrating Population, Community, & Landscape Perspectives, Joshua T. Armstrong

Theses and Dissertations

Aquatic plants, macrophytes, are foundational components of freshwater ecosystems, influencing abiotic conditions, providing habitat structure, and shaping biodiversity and community assembly processes. Their role is particularly critical in dynamic systems where disturbance regimes and colonization processes interact to shape community patterns and species distributions. Despite their ecological importance, macrophytes remain underrepresented in theoretical and applied studies of metacommunity dynamics and invasion ecology, especially in natural systems experiencing frequent environmental fluctuations. Here we aim to elucidate how macrophytes influence and respond to spatial and temporal variation in aquatic ecosystems, with a particular focus on colonization-extinction dynamics, invasion success, and community assembly. …

Distribution And Ecology Of The Cedar Keys Mole Skink (Plestiodon Egregius Insularis), Kevin M. Enge, Louis A. Somma, Paul E. Moler, Travis M. Thomas, Matthew T. Fedler, John M. Matter, Dennis C. Haney

Papers in Herpetology

We conducted surveys for the Cedar Keys Mole Skink, Plestiodon egregius insularis (Mount), during 1989– 1999 and 2015–2024, examined museum vouchers, and compiled personal observations from others to determine the status and distribution of this subspecies, which has the smallest geographic distribution of the five subspecies and is being considered for federal listing. We observed Cedar Keys Mole Skinks on Airstrip Island, Atsena Otie, Cedar Point, Deer Island, North Key, Scale Key, Seahorse Key, Snake Key, and possibly Dog Island. We have anecdotal reports of Mole Skinks on Way Key, which contains the most potential habitat and is the main …

Roosting Habits Of Male Silver-Haired Bats In The Willard Creek Drainage Of Northeastern California, Alexander Christopher Lewis

Cal Poly Humboldt theses and projects

Silver-haired bats (Lasionycteris noctivagans) are one of the most widely distributed forest bats in North America. Although wildfires have been increasing across their range, how they respond to wildfire is understudied. Previous studies on silver-haired bats and fire focused on roosting behavior in low-severity controlled burns or used acoustics to understand activity levels post-wildfire. Quantifying how silver-haired bats use the physical structures created by high-severity wildfires and the landscape features in which they occur is critical in the face of rapidly shifting fire regimes. During the summer of 2023 and 2024 I radio-tracked male silver-haired bats to 37 roosts …

Investigating Fish Communities As Part Of The Food Web In Artificial Tidal Wetland Ponds Of Humboldt Bay, Ca, Lily M. Olmo

Cal Poly Humboldt theses and projects

In the face of global wetland loss, artificially created wetlands have the potential to restore ecosystem services for humans while also providing habitat for fish and wildlife. This study explored fish communities in three understudied artificial wetland ponds that are connected to Humboldt Bay in northern California and known to be important wildlife foraging areas. The objectives of this research were to 1) Characterize the environmental conditions of each pond, 2) Calculate the relative catch, richness, diversity, and biomass of fish in each pond, 3) Describe the movement of fish into and out of the ponds with the tides, and …

Examining The Effects Of Songbird Nest Boxes And Habitat On Avian And Arthropod Communities In A Vineyard Ecosystem, Eleanor Macdonald

Cal Poly Humboldt theses and projects

Agricultural expansion threatens biodiversity, but integrating insectivorous birds into vineyard ecosystems may support both conservation and ecosystem services. We tested how nest boxes and habitat composition influence avian and arthropod communities in Napa Valley vineyards using a before-after, control-impact experiment across 20 sites. During the 2023-2024 breeding seasons we conducted avian point counts, sampled key pest and beneficial arthropods, and collected fecal samples from adult and nestling tree swallows (Tachycineta bicolor) and western bluebirds (Sialia mexicana) to detect vineyard pest DNA. Nest boxes significantly increased swallow and bluebird abundance within one year; swallow responses were strongest …

Exploring Coastal Plain Fish Ecology Across A Range Of Early-Life-History Traits And River Types, Bridgette Nicolosi

College of Graduate Studies: Theses & Dissertations

The ecological complexity of southeastern Coastal Plain rivers is reflected in the diversity of fish communities they support, yet the processes structuring early life dynamics remain poorly understood. This thesis explores the influence of environmental gradients on larval fish assemblage composition and American Shad (Alosa sapidissima) spawning phenology across two Georgia Coastal Plain river systems.

In the unregulated Ogeechee River, I investigated spatial and temporal variation in larval fish communities by comparing mainstem and tributary habitats to understand the role of tributaries in watershed-wide larval production. Larvae were collected biweekly from May to September 2024 at eight paired mainstem-tributary sites …

Adaptive Evolution Shapes The Transmissibility Of West Nile Virus In New York State, Sean M. Bialosuknia

Electronic Theses & Dissertations (2024 - present)

Arthropod-borne viruses (arboviruses), which are maintained in nature in complex transmission cycles involving hematophagic invertebrates and their vertebrate hosts, are the cause of a significant and expanding global health burden. Defining arbovirus-host interactions is necessary if we are to understand the adaptive and epidemiological potential of arboviruses. The results presented with West Nile virus (WNV Flaviviridae: Orthoflavivirus), are a compilation of such studies. WNV is the most prevalent arboviral pathogen in the U.S. and the most geographically distributed arbovirus in the world. Despite the evolutionary potential of these RNA viruses, WNV and other arboviruses have experienced only limited …

Endocrine Responses To Two Distinct Foraging Contexts In The Bonobo (Pan Paniscus), Lauren Mitchell

Master's Theses

In gregarious animals, a social structure characterized by female dominance is relatively rare. However, bonobos (Pan paniscus), one of the two species most closely related to humans, are characterized by partial female dominance, with females forming close social bonds. In contrast, chimpanzees (Pan troglodytes), a close relative of the bonobo, are characterized by strong male-male bonding and social dominance with female chimpanzees lacking close social bonds. There is a lack of consensus concerning the reasons for these behavioral differences in Pan, specifically, the physiological processes responsible for female dominance in bonobos. The role of hormones …

Mountain Pine Beetle Host Tree Selection And Climate-Growth Dynamics In Whitebark Pine, Hannah Rose Alverson

Graduate Student Theses, Dissertations, & Professional Papers

Recent climate-driven outbreaks of mountain pine beetles (Dendroctonus ponderosae) in whitebark pine (Pinus albicaulis) have raised fears of increasing whitebark pine mortality with increased warming and drought due to climate change. However, little is known about how whitebark pine responds to climate, what characteristics may predict whitebark pine susceptibility to mountain pine beetle outbreaks, or how these may interact. This information is critical in understanding how whitebark pine might persist in a changing climate. My research investigated how whitebark pine growth responds to various climate variables and how these responses may be predictive of attack by …

Exploring Mating Patterns: The Interplay Of Genes, Environment, And Their Evolutionary Outcomes, Sanduni Talagala

Theses and Dissertations (Comprehensive)

There is great variation in the reproductive tactics exhibited both between and within different species, which is reflected in how individuals engage in mate assessment, mate choice and offspring production. It is therefore important to understand general mating patterns of populations, the factors that influence these mating patterns, and the consequences they carry, in order to get a more holistic understanding of mating systems. This doctoral research represents a multi-pronged investigation of the factors shaping mating patterns and their consequences, how environmental factors influence mating patterns, and how both genotypes and the environment interact to influence mate choice decisions and …

A Mystery Of Microecology: Revealing The Ecological Relationship Between Allorhizobium Vitis And Missouri Native Grape Species, Hunter White

Graduate Theses/Dissertations

Crown gall disease can be very detrimental to grape and wine producers around the world by reducing vine vigor and yield. It is caused by the bacteria Allorhizobium vitis (A. Vitis) carrying a tumor inducing (Ti) plasmid. The A. vitis bacteria have been found in soil and cane tissues in vineyards around the world, and infect all cultivated grapes. However, there have been no reports of crown gall on native wild grapevines, and very little is known about the ecology of A. vitis in native ecosystems. I have sampled cambium tissues from three native wild grape species of …

Restoration Of Giant River Cane (Arundinaria Gigantea) In Southwest Missouri, Lyndsey D. Rightnowar

Graduate Theses/Dissertations

Giant river cane (Arundinaria gigantea), a native bamboo species, once dominated riparian landscapes across the southeastern United States but has declined to approximately 2% of its historic range. This study evaluated restoration techniques for giant cane in southwest Missouri by examining the influence of rhizome source (putative genotype), planting type, and restoration site on restoration success. I compared two planting types: greenhouse-to-field (G2F) transplanting, where rhizomes were first propagated in the greenhouse before planting, and field-to-field (F2F) transplanting, where rhizomes were directly transplanted from source canebrakes to restoration sites. Rhizomes were collected from four existing canebrakes in Taney …

Seasonal Occupancy Of The Thermal Plume Of A Spring Tributary To The South Fork Roanoke River, Virginia., Steven L. Powers, Michael M. Calvert, Charlotte M. Spaulding

Southeastern Fishes Council Proceedings

Detection of temperate stream fishes varies widely across seasons as streams teeming with life in summer often appear empty during winter sampling efforts. While much literature documents the disproportionate use of the thermal plumes of spring tributaries by cold water fishes during summer, few studies have investigated occupancy of those habitats by warm water fishes in winter. We conducted quantitative snorkeling observations within the near uniform temperatures (10-14^oC) of the thermal plume of a spring tributary to the South Fork Roanoke River across seasons and compared number of fishes observed and species richness to control observations made just …

Invasion Stress Mitigates Climate Stress In A Brackish Marsh Amphipod, Lorna E. Haworth, Sarah Nancollas, Susie N. Landa, Anne E. Todgham, Richelle L. Tanner

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

1. Organisms in coastal brackish ecosystems face not only highly variable environmental conditions, but the intensity and stochasticity of these environmental conditions are anticipated to increase due to climate change. While environmental changes are often presented unilaterally as stressors, there are some anthropogenic environmental transformations, such as the introduction of habitat forming plant species, that may mitigate physiological stress imposed by warming. In Suisun Marsh in the California Delta, native plant canopies allow light and heat to penetrate to the understory yet the canopies of the introduced Phragmites australis reed block out sunlight and heat for organisms living below.
2. We set …

Identifying Opportunities For Nature-Based Solutions With Geospatialized Life Cycle Assessments And Fine-Scale Socioecological Data, Gabriela Shirkey, Annick Anctil, Ranjeet John, Venkatesh Kolluru, Leah Mungai, Herve Kashongwe, Lauren T. Cooper, Ilke Celik, Joshua B. Fisher, Jiquan Chen

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

As we increasingly understand the impact that land management intensification has on local and global climate, the call for nature-based solutions (NbS) in agroecosystems has expanded. Moreover, the pressing need to determine when and where NbS should be used raises challenges to socioecological data integration as we overcome spatiotemporal resolutions. Natural and working lands is an effort promoting NbS, particularly emissions reduction and carbon stock maintenance in forests. To overcome the spatiotemporal limitation, we integrated life cycle assessments (LCA), an ecological carbon stock model, and a land cover land use change model to synthesize rates of global warming potential (GWP) …

Ecological Niches Applied To Socioeconomic Phenomena: The Case Of The Colombian Internal Conflict, Alexander Alegría, Laura Jiménez, Jhon Jairo Alvarado-Quintero

Peace and Conflict Studies

Recent studies of the Colombian conflict have shown that struggle for resource accumulation and territorial control, in a very competitive and violent environment in which the illegal armed groups are involved, is crucial to their survival and development. Here, we applied a highly successful methodology from ecology (Ecological Niche Modelling) to the problem of identifying the ideal socioeconomic conditions for the presence of a Colombian illegal armed group, named the Revolutionary Armed Forces of Colombia (FARC). We analyzed some determining factors of FARC´s presence and permanence within the Colombian territory that reflect aspects of the socioeconomic dynamics and productive capacity …

Study Of The Brain Anatomy Of Three Extinct Marsupials: Thylacinus Cynocephalus, Thylacoleo Carnifex, And Silvabestius Johnnilandi, Francisco Garcia

Honors Program Theses and Research Projects

Marsupials are pouched mammals that today are mainly found in Australasia and South America. Marsupials have proven to be quite intriguing to evolutionary biologists who note how some marsupials resemble placentals in anatomy due to convergent evolution, with both marsupials and placentals filling similar niches in their respective environments. As of today, studies interested in marsupial brain evolution have published descriptions of cranial endocasts for several species of marsupials, with the number of descriptions seeing a massive boost over the last 20 years with the arrival of CT imaging technology. However, no comprehensive study of brain evolution in marsupials has …

Analyzing Head Morphology Trends With Increasing Population Density In A Jamaican Lizard Species, Lillian Durand

2024 Fall Honors Capstone Projects - Archive

Anolis lizards are model organisms for studying natural selection and evolutionary processes. One trait that is hypothesized to be advantageous for males is head size, as larger heads lead to stronger bite forces and increased likelihood in outcompeting other males for mates. To better understand how linked head size and intraspecific competition are, the head morphology of male A. lineatopus was analyzed among Jamaican populations with varying levels of population density. Population densities were determined using standardized plot surveys and mark resight models. Head dimensions and body condition for individual lizards were measured at each site. My study found that …

Evaluating The Roles Of Pollinators In Shaping The Floral Color Variation Of Phacelia Dubia, Katherine Riddle

All Theses

Floral color variation within a species is a common occurrence and its maintenance has been a long-standing question in evolutionary biology. Differences in flower color between populations can be shaped by pollinator-mediated selection. Pollinators can exhibit innate and learned preferences for color that may influence floral color variation. These preferences may be molded by the visual environment in which pollinators forage. Most current understanding of how pollinators shape floral color variation involves dramatic differences in dominant pollinators between populations (e.g., hawkmoth vs. bee) and most behavioral work utilized model pollinators like honeybee and bumble bee. However, less is known about …

Lateral Dispersal Of Adult Trichoptera: Flight Distance And Traveling Pattern, Peilin Tan

All Theses

Trichoptera species (caddisfly) are usually used as bio-indictors for surface water quality due to their sensitivity to environmental changes, and if assessing water quality with light-trapped adults, knowing their travelling patterns will improve the accuracy of such assessments. To investigate how far a caddisfly will migrate from their emerging stream, three streams in South Carolina with different widths (Wildcat Creek 1.2 m, Brasstown Creek 11.2 m and Chattooga River 26.95 m) were selected for this study with light traps placed at three distances (0 m, 50 m, 100 m) from the streams. How long and when? Both species richness and …

Soil Data From Spring Run Conservation Area, Dayton, Ohio, Madelaine Gregory, Valerie N. Thurston, Michaela J. Woods, Ryan W. Mcewan

Data Files: Ecosystem Restoration Following Industrial Agriculture

This spreadsheet contains soil data from an experiment in the Spring Run Conservation Area in Dayton, Ohio, USA (39° 46 '42.2"N, 84° 20' 52.5"W). Details of the data collection can be found in the master's thesis "The State of Soil Streamlines Secondary Succession: Remediating Degraded Soils in a Post-Agricultural Field."

Bioindicators Of Mercury In Riverine Systems, Kathryn Mudica

All-Inclusive List of Electronic Theses and Dissertations

This study focuses on the bioaccumulation and biomagnification of mercury in freshwater food webs, with emphasis on bioindicators, such as macroinvertebrates, crayfish, and river otters. Despite regulatory efforts and advancements in monitoring, significant gaps remain in understanding mercury dynamics in freshwater systems—especially regarding its transport, methylation, and bioavailability across different ecosystems. To address these knowledge gaps, this study adopts a biocentric approach, emphasizing the role of living organisms in their environment. By utilizing macroinvertebrates, crayfish, and river otters as bioindicators, we aim to assess mercury bioavailability and distribution. These organisms provide varying temporal and spatial scales of mercury accumulation, offering …

Investigation Of Reproductive Inhibition During Chronic Heat Stress In C. Elegans, Macy Makenna Nielander

Theses and Dissertations

Nearly all organisms experience heterogeneity in environmental conditions that can negatively impact fitness. A common adaptive strategy to reduce the impact of this stress is called facultative diapause, where development and reproduction are temporarily arrested to promote survival. Facultative diapause is characterized by three major criteria, the arrest must be (i) induced by an unfavorable environmental condition, (ii) reversible, and (iii) driven by genetically regulated mechanisms. The aim of this thesis was to determine whether chronic heat-induced inhibition of egg laying in Caenorhabditis elegans represents a novel form of facultative diapause. It was found that the inhibition of egg-laying is …

Changing Characteristics Of Land Cover, Landscape Pattern And Ecosystem Services In The Bohai Rim Region Of China, Jiaqi Liu, Wei Chen, Hu Ding, Zhanhang Liu, Min Xu, Ramesh P. Singh, Congqiang Liu

Mathematics, Physics, and Computer Science Faculty Articles and Research

Since the Anthropocene, ecosystems have been continuously deteriorating due to global climate change and human intervention. Exploring the changing characteristics of land use/land cover (LULC), landscape pattern and ecosystem service (ES) and their drivers is crucial for regional ecosystem management and sustainable development. Taking the Bohai Rim region of China as an example, we used the land use transfer matrix, landscape pattern index and InVEST model to analyze the changing characteristics of LULC, landscape pattern and six key ESs [crop production (CP), water yield (WY), carbon storage (CS), soil conservation (SC), habitat quality (HQ), landscape aesthetics (LA)] during 2000–2020. Detailed …

Human Impacts On Mammal Diversity From The Pleistocene To The Present, Carson P. Hedberg

Biology ETDs

Humans have fundamentally altered the planet’s biodiversity. It is critical to characterize these changes, but also to understand how they impact the structure and function of modern ecosystems. This dissertation investigates how anthropogenically mediated species losses and/or introductions influence ecological function and community structure in mammals across multiple temporal and spatial scales. We found that selective loss of large-bodied mammals over the Late Quaternary has led to severe losses in functional diversity in modern ecosystems, suggesting megafaunal mammals contribute distinct ecological functions. These changes to mammal diversity and distribution over millennia have altered both global patterns in functional diversity and …

Mathematically Modeling How Trapping Specific Crayfish Life Stages Impacts Removal Efficacy, Relena Pattison, Courtney L. Davis

Annual Symposium on Biomathematics and Ecology Education and Research

No abstract provided.

Examining Wildfire Dynamics Using Ecostress Data With Machine Learning Approaches: The Case Of South-Eastern Australia's Black Summer, Yuanhui Zhu, Shakthi B. Murugesan, Ivone K. Masara, Soe W. Myint, Joshua B. Fisher

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Wildfires are increasing in risk and prevalence. The most destructive wildfires in decades in Australia occurred in 2019–2020. However, there is still a challenge in developing effective models to understand the likelihood of wildfire spread (susceptibility) and pre-fire vegetation conditions. The recent launch of NASA's ECOSTRESS presents an opportunity to monitor fire dynamics with a high resolution of 70 m by measuring ecosystem stress and drought conditions preceding wildfires. We incorporated ECOSTRESS data, vegetation indices, rainfall, and topographic data as independent variables and fire events as dependent variables into machine learning algorithms applied to the historic Australian wildfires of 2019–2020. …