Life Sciences Commons^™

Top Down Effects And Resource Selection By Coyotes In South Carolina, Alex Jensen

All Dissertations

Top predators play important roles in functioning ecosystems, including regulating the populations of prey species and competing with other predators. However, in the face of global change, many top terrestrial predators have declined in both range and abundance, making room for some smaller predators to expand into new niches. Coyotes (Canis latrans) in North America are a prime example of this – they have rapidly expanded their range in the last 120 years, raising concerns about their impacts on both domestic and wild species. In eastern North America, research has centered around their effects on white-tailed deer ( …

The Effects Of Floral And Social Information On Bumblebee Forager Learning And Memory, Avery Hume Baker

Theses

Bumblebees rely on information gathered from their environment to make the best choices they can when foraging for pollen and nectar. The type of information gathered should influence how a bee learns and remembers it, but other factors such as the size of the bee’s brain may also play a role in the learning and remembering process. While social information learned from other organisms and information gathered directly from flowers can each be used alone to improve both the efficiency with which a bee learns to forage from a flower and how accurately and how long the bee remembers these …

Competing Behaviors Of Thermoregulation And Ambush Foraging In The Timber Rattlesnake (Crotalus Horridus Horridus): A Mechanistic Assessment Of Thermal Conduction, Larry K. Kamees

Graduate Theses and Dissertations

The interaction between the biophysical environment and ectotherm morphology elicits behaviors designed to maintain internal body temperature (Tb) within a range that promotes physiological functions. The short-term requirements of mass (energy requirements) and heat balance are subject to tradeoffs imposed by the organisms current physiological (heat and mass budgets) and environmental (biophysical, demographic, social, and predation) constraints and available resources. In temperate forests, extreme temperatures are common in summer even with intermittent sun exposure due to dense canopy cover. In Spring and Fall, temperatures can range from below freezing to 35 ℃ in 24 hrs. An ambush predator like the …

Impacts Of Sea Ice Loss On Polar Bear Diet, Prey Availability, Foraging Behaviors, And Human-Bear Interactions In The Arctic, Jasmin Chen

Master's Projects and Capstones

Anthropogenic-induced climate change has warmed the Arctic 2-3 times faster than the rest of the world, causing sea ice declines that introduce challenges for specialist species, such as polar bears, in adapting to rapid environmental changes. Comparative and quantitative analyses of three Hudson Bay polar bear subpopulations were used to determine the impacts of sea ice loss on polar bear diet, prey availability, foraging behaviors, and human-bear interactions in the Arctic. The study reveal that Hudson Bay polar bears experience the most severe impacts from sea ice declines, resulting in a 30% population decline. Due to their smaller body size, …

Pilfering Passerines? Inter-Class Competition: A New Direction In Foraging Ecology, Shannon Gillen

Masters Theses, 2020-current

Life in the epigeal layer below leaf litterfall often goes unexplored. Shrews (Soricidae, 1910) have foraged in this microhabitat for millions of years, carving out an existence in harsh habitats around the world, ranging from the tropics to subarctic boreal tundra. Two shrew species that inhabit the Shenandoah Valley of Virginia, the least shrew (Cryptotis parva) and northern short-tailed shrew (Blarina brevicauda), were the focus of this study. Shrews make epigeal foraging trails while they continually forage for food, and caching is a way to save this food for times of low and sporadic food availability. …

Food Caching Decisions In Canada Jays (Perisoreus Canadensis), Robert J. Martin

Electronic Thesis and Dissertation Repository

Food scarce periods pose serious challenges for birds, particularly when those periods coincide with demanding life history stages such as overwintering. For resident birds in the Northern hemisphere, resource scarcity typically occurs simultaneously with winter conditions. In order to combat these compounded stressors, some species cache food to ensure a reliable supply of resources. Food caching is the storing of food items for subsequent retrieval and consumption after some delay. Canada Jays (Perisoreus canadensis) are year-round residents of the North American boreal forest and some high elevation areas in the United States, and cache food to combat resource …

Avian Attractiveness To Vertically Polarized Light, Aurora Belle Kuczek

Senior Projects Spring 2021

It is well-known that many animal species can detect polarized light cues of water and water-like objects in the visible and ultraviolet range. However, studies investigating if birds can see polarized light in field-based settings are rare. Furthermore, no studies have yet been conducted to understand avian attractiveness to vertically polarized light, nor have studies considered other natural polarizers of light such as tree sap. I designed a choice-field experiment to investigate if birds can detect, and are attracted to vertically polarized light. First, I cut six pieces of clear vinyl into a foot by 54 inches. I painted each …

Defining Bee Pollinator Community Composition In Tennessee Soybean, Andrew L. Lawson

Masters Theses

Two planting dates of various soybean varieties were planted in Jackson and Knoxville, TN during 2018 and 2019 with the overall intent of surveying the diversity bee (Hymenoptera) genera in these agroecosystems and also to assess the potential for using late maturing soybean as a food resource for bees during the dearth of floral resources that often occurs during the fall. We also investigated how manipulating planting dates and soybean variety selection affected the occurrence of insect pests that occurred in the soybean.

Both active (netting) and passive (bee bowls and blue-vane traps) sampling were used to collect the bees, …

Foraging Strategy Plasticity In Fiordland Penguins (Eudyptes Pachyrhynchus): A Stable Isotope Approach, Jeffrey Wayne White

Theses, Dissertations and Capstones

Foraging ecology in the crested penguins (genus: Eudyptes) is an active area of research, with new techniques rapidly increasing our understanding of these charismatic species. The most common techniques to assess foraging ecology include stomach content analysis, fecal DNA analysis, stable isotope analysis, tracking, and video loggers. Here we review dietary research on all 8 taxa within the genus Eudyptes to identify gaps in our current knowledge. However, foraging studies that assess dietary segregation require a method for quickly and accurately sexing penguins in the field. Obvious sexual dimorphism in plumage is largely absent in penguins leaving behavioral cues …

Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning

LSU Master's Theses

I coupled fine-scale environmental data with observed behavior and group composition data to examine overall distribution within the bay system and to characterize the habitat associated with foraging and the presence of calves. Semi-isolated populations of bottlenose dolphins (Tursiops truncatus) along Louisiana’s coast are undergoing increased risks from boat traffic, oil spills, land subsidence, and planned water diversions (CPRA 2017). Characterizing the habitat use of bottlenose dolphins in Terrebonne and Timbalier bays, Louisiana, is important given the likely high site fidelity, small home ranges, and low exchange of individuals with nearby coastal populations (Lane et al. 2015, McDonald …

Population Demographics And Active Foraging Behavior Of Copperheads (Agkistrodon Contortrix) At A Recreational Site In Eastern Kentucky, Jocelyn Hendricks

Online Theses and Dissertations

Recreational areas represent a significant source of human-wildlife interaction, which can have an especially negative effect on organisms, like snakes, that are generally perceived as dangerous by the public. Considering the projected increase in recreation rates in the United States, the threat to this already vulnerable group of organisms deserves attention. While habitat factors associated with recreational areas—fragmentation, decreased canopy cover, altered vegetation composition—have been shown to affect snake thermoregulatory behavior and abundance, detailed studies of wild snake behavior are uncommon due to their cryptic nature. The goal of this study was to reduce human-wildlife conflict at a recreational site …

The Effect Of Shelter Availability On Foraging In Atlantic Salmon (Salmo Salar), Christian A. Therrien

Electronic Thesis and Dissertation Repository

Shelter is an environmental feature that provides protection from danger and its use is an important anti-predator behavior for juvenile Atlantic salmon (Salmo salar). However, how shelter availability influences the foraging of these fish in the wild is not well documented. I predicted that juvenile Atlantic salmon would alter their foraging behavior in a low shelter environment and that this effect would differ between individuals from two populations that are targeted for reintroduction into Lake Ontario. I measured the foraging activity of juvenile Atlantic salmon from the two populations while they were held in pens in a Lake …

Foraging Behavior, Taxonomy, And Morphology Of Bees (Hymenoptera: Apoidea), With An Emphasis On Perdita (Hymenoptera: Andrenidae), Zachary M. Portman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bees are the most important pollinators of flowering plants and are necessary for pollinating both wild plants and many of the crops that produce the food we eat. There are many different species of bees, with about 20,000 species worldwide and 4,000 species in the United States. Even though bees are important pollinators, there is still much we do not know about how many species there are and their biology. In order to better understand the species and their biology, I performed three projects that help fill these gaps by reviewing the species of a poorly known bee group, examining …

The Dynamic Nature Of Forage Preference And Microhistological Atlas, John J. Henderson

Dissertations, Master's Theses and Master's Reports

Moose, Alces alces, are among the most iconic species in the northern circumpolar temperate forests. Multiple factors influence moose density. Winter is a time of severe dietary stress for moose because deciduous trees are leafless and available forage is limited to conifers with high plant secondary metabolites or low-energy deciduous twigs. Forage preference depends on the intrinsic forage properties, abundance of forage and environmental stressors. These stressors include predation risk and severity of climate that affect forage efficiency. We examined forage preference of moose on Isle Royale National Park during winter over a ten-year period. Diet was divided into …

Ecological And Oceanographic Influences On Leatherback Turtle Behavior And Scyphozoan Jellyfish Distributions In The Gulf Of Mexico, Katrina Aleksa

Dissertations

Leatherback turtles (Dermochelys coriacea) are a wide-ranging, oceanic species that feed exclusively on gelatinous zooplankton. Leatherback have been spotted in the Gulf of Mexico (GoM) for several decades and consistently had a high level of interactions with longline fisheries. However, no quantitative studies have been performed to address the spatiotemporal distribution of these turtles in the GoM. This research determines 1) leatherback movements and high-use areas in the GoM, 2) their association with oceanographic features, 3) the distribution and density of two abundant medusae in the northern GoM and any association with biophysical parameters, and 4) the body …

The Evolution Of Fear Ecology: A Fruit Fly (Drosophila Melanogaster) Perspective, Itachi Mills

Theses

Several mechanisms underlie how evolutionary lineages respond to predation pressures or predation risk. Further mechanisms link evolutionary predation responses to how animals forage, or find mates. However, gaps remain in our understanding about how predation and foraging interact in an evolutionary context.

In my first chapter, I elaborate on how predation and foraging relate in to one another in ecological, evolutionary and behavioral contexts. I start out with an overview of fear ecology. Then, I outline how trade-offs influence the evolution of morphological, chemical and behavioral responses to predation. I further elaborate on how these trade-offs influence reproduction. Finally, I …

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 …

Effects Of Roads And Trails On Peaks Of Otter Salamander (Plethodon Hubrichti) And Eastern Red-Backed Salamander (Plethodon Cinereus) Movement Behavior, Cory Benjamin Goff

Theses, Dissertations and Capstones

Habitat fragmentation negatively affects movement and dispersal of wildlife by altering useable space and creating barriers. The objective of this study was to assess impacts of fragmentation by roads and trails on the movement behavior of two terrestrial, woodland salamander species. I evaluated whether proximity to roads and trails affected the movement behavior of two species: the Peaks of Otter Salamander (Plethodon hubrichti), a species of special concern, and the Eastern Red-backed Salamander (Plethodon cinereus). I examined movement behavior in three treatments: paved roads, gravel roads and hiking trails. I compared treatments to controls located at least 200m from treatment …

Context-Dependent Individual Variation In Foraging Behaviour And Parental Care In House Sparrows, David Moldoff

Theses and Dissertations--Biology

Behaviors can exhibit a wide degree of plasticity depending on the environmental context in which they are expressed. Despite this, repeatable differences have been found among and within individuals across a wide range of taxa. For my thesis, I investigated individual differences in foraging and parental care. In the first experiment, I assessed house sparrows (Passer domesticus) for domain-generality among neophobia, habituation and associative learning as they are all responses to novelty. While the results of the study find individual differences in each of these contexts the conclusion supported separate mechanisms for each response (domain-specificity). In the second experiment, I …

The Effects Of Predation Risk And Thermoregulation Cost On The Foraging Behavior Of The Eastern Grey Squirrel (Sciurus Carolinensis), Anne E. Collier

Senior Theses and Projects

In this study, the effects of predation risk and thermoregulation cost on the foraging behavior of the urban eastern gray squirrel (Sciurus carolinensis) were examined. There were two objectives. The first was to determine if either thermoregulation cost or predation risk had a more significant effect on foraging behavior. The second was to find out if foliar cover or distance to refuge was a more important cue of predation risk. To accomplish these goals, giving-up density and temperature data were collected at feeding trays both under the canopy and outside of the canopy at two deciduous trees and …

How Important Is Land-Based Foraging To Polar Bears (Ursus Maritimus) During The Ice-Free Season In Western Hudson Bay? An Examination Of Dietary Shifts, Compositional Patterns, Behavioral Observations And Energetic Contributions, Linda J. Gormezano

Dissertations, Theses, and Capstone Projects

Trophic mismatches between predators and their prey are increasing as climate change causes decoupling of phenological relationships. Predators linked to the life histories of a particular prey will have a more difficult time persisting through environmental change unless they can alter their behavior to maintain the historical match or possess the ability to pursue alternate prey. Arctic predators typically possess flexible foraging strategies to survive in the labile environment, however, quantifying the limits of those strategies can be difficult when life history information is incomplete. In such cases, piecing together different aspects of a predator's foraging behavior, particularly when environmental …

The Foraging Areas Of Attine Ants At The Firestone Reserve, Costa Rica, Elana A. Goldstein

Scripps Senior Theses

In tropical forest systems, attine ants are the dominant herbivores. They construct large nest structures that include foraging trails that extend to multiple plant sources throughout the forest. These foraging areas vary from nest to nest and they are highly dynamic over time and season changes. It was expected that characteristics of both the nest structure and the surrounding environment would affect the size of nest foraging areas. In this study, COMPASS survey software and ArcGIS were used to map the foraging trails and calculate the foraging areas of 12 attine ant nests located on the Firestone Reserve, over the …

Ecology And Flock-Following Behavior Of The Wedge-Billed Woodcreeper In Eastern Ecuador, Abigail Darrah

Graduate Theses and Dissertations

The wedge-billed woodcreeper (Glyphorynchus spirurus) is a common understory suboscine passerine of lowland Neotropical rainforests. It frequently joins mixed-species understory flocks but also regularly forages alone, and thus is an excellent model species on which to conduct comparative behavioral observations to examine the hypothesized costs and benefits of flock-following. Individuals exhibit variable flocking propensities (proportion of time spent with flocks), and thus observing the correlations between flocking propensity and physical and environmental factors can provide further insight into the importance of flock-following to the ecology of this species. Despite its abundance at many sites and its wide geographic range, surprisingly …

Winter Behavior And Ecology Of Eastern Bluebirds (Sialia Sialis): Home Ranges, Habitat Use, And Effect Of Weather On Foraging Behavior, Todd J. Weinkam

Online Theses and Dissertations

Eastern bluebirds (Sialia sialis) are widespread across eastern North America, but populations appear to be susceptible to extreme winter weather. Declines in population following cold winters in states like Kentucky suggest the need to better understand winter-specific habitat requirements and behavioral responses to inclement weather. My objectives were to 1) describe the size and habitat composition of the home ranges of wintering bluebirds, and 2) examine the effects of weather (i.e., temperature, wind speed, and snow presence) on habitat occupancy, group size, and foraging behavior. My study was conducted at the Blue Grass Army Depot in Madison County, …

Stable Isotope Analysis (Delta Nitrogen-15 And Delta Carbon-13) And Bioenergetic Modeling Of Spatial-Temporal Foraging Patterns And Consumption Dynamics In Brown And Rainbow Trout Populations Within Catch-And-Release Areas Of Arkansas Tailwaters, Jon M. Flinders

Graduate Theses and Dissertations

I examined spatial and temporal consumption dynamics using an energy intake model and a bioenergetics model of rainbow trout, Oncorhynchus mykiss, and brown trout, Salmo trutta, within three catch-and-release (C-R) areas in Bull Shoals and Norfork tailwaters to determine whether trout populations were limited by food supply. I also examined the seasonal and ontogenetic shifts in the foraging patterns of brown and rainbow trout within these areas using gut content analysis (GCA) and stable isotope analysis (SIA) of C and N. I examined 605 brown trout and 768 rainbow trout for GCA and SIA at Bull Shoals, Norfork, …

Space Use And Mating Activities In The Speckled Rattlesnake, Xavier Glaudas

UNLV Theses, Dissertations, Professional Papers, and Capstones

Our understanding of space use variation in response to the temporally varying importance of specific resources is poorly understood in reptiles, because spatial studies are rarely placed into an explicit ecological and behavioral context. I examined how space use differed between the mating and post-mating seasons, and how this variation related to three important resources, mating partners, food, and refuge, in an adult population of the speckled rattlesnake Crotalus mitchellii in the Mojave Desert of southwestern North America. During the mating season (late April to early June), Crotalus mitchellii increased distance traveled per unit time, because wide-ranging behavior likely enhances …

Factors Affecting Adult Foraging And Chick Growth Of Adélie Penguins (Pygoscelis Adeliae) Off The Western Antarctic Peninsula: A Modeling Study, Erik W. Chapman

OES Theses and Dissertations

Coupled individual-based models that simulate Adélie penguin ( Pygoscelis adeliae) chick growth and adult foraging behavior during the chick growth period were developed and used to explore factors that influence chick fledging mass and adult foraging energetics off the western Antarctic Peninsula (WAP). Adélie penguin colonies in this region are undergoing changes in population size that have been correlated with climate-driven alteration of the marine and terrestrial environment. Simulations were selected to highlight possible mechanistic linkages between climate variability and chick growth and adult foraging processes. These processes were the focus of this study because chicks that fledge at …

Integrated Responses Of Crustaceans Inhabiting Estuaries To The Challenges Of Feeding And Digestion In Low Salinity, Daniel Luke Curtis

UNLV Theses, Dissertations, Professional Papers, and Capstones

Estuaries are highly productive and serve as vital habitats for numerous decapod crustacean species. However, the environmental conditions within estuaries are often highly dynamic and subject to large changes in salinity and temperature that occur on seasonal and tidal scales. Not all of the species occupying these habitats are adept in coping with changes in these environmental conditions. This dissertation describes the influence of low salinity conditions on the 1) habitat preference, 2) feeding behaviour and 3) digestive physiology of crustaceans inhabiting estuaries. I have primarily focussed on a weak osmoregulator, the Dungeness crab, Cancer magister , but have also …

A Population Survey And Foraging Analysis Of The Double-Crested Cormorant (Phalacrocorax Auritus) On The Santee Lakes, South Carolina, Adam Kelley

All Theses

This study was designed to determine whether Double-crested cormorants (Phalacrocorax auritus) were having an impact on the Santee lakes fishery for Striped bass (Morone saxatilis). I surveyed the lakes' population in the summer of 2007 and winter of 2008 to determine population levels and 76 birds were necropsied in order to determine foraging preferences. Summer populations were estimated at 203 birds and winter at 6000. Clupeids (primarily Gizzard, Threadfin, and American shads) made up the bulk of the diet in both seasons with an overall percentage of 86.19%. No bass of any size or species were found in the stomachs …