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 …

Winter Diet Of Montezuma Quail In Arizona And New Mexico, Oscar E. López-Bujanda, Alberto Macías-Duarte, Reyna A. Castillo-Gámez, Angel B. Montoya

National Quail Symposium Proceedings

Investigating the diet composition of Montezuma quail (Cyrtonyx montezumae) is fundamental for unveiling how food resources limit the species’ population size and may provide relevant tools for their harvest and habitat management. The objective of this research was to determine the composition and geographic variation of the winter diet of the Montezuma quail in Arizona and New Mexico, USA, from quail crops harvested during the hunting seasons of 2008–2017. In addition, we used beta regression analyses to determine the effect of environmental factors and ecological variables (annual mean precipitation, annual mean temperature, landscape diversity, diet diversity, time of …

Behavioral State-Specific Northern Bobwhite Chick Resource Selection, Justin N. Hill, Theron M. Terhune Ii, James A. Martin

National Quail Symposium Proceedings

Determining resource selection rates for all life stages of a species is critical to enable a holistic management approach that focuses on bolstering populations across all life stages. Moreover, tying these selection rates to specific life history needs (e.g., foraging, roosting, and loafing) can provide valuable information to guide management practices. Northern bobwhite (Colinus virginianus; hereafter, bobwhite), a gallinaceous species of North America, has experienced steady population declines throughout much of its range over the last 50 years. Although the species has been well studied, chick ecology is still relatively unknown. We studied bobwhite chick resource selection on …

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, …

Do Eastern Gray Squirrels (Sciurus Carolinensis) Use Human-Provided Cues To Increase Foraging Success In Urban Landscapes?, Aditya A. Mehta, Jeeva H. Rathnaweera

Undergraduate Arts and Research Showcase

The coexistence of humans with other animals in urban and suburban areas has given rise to a spectrum of agonistic and beneficial interactions. Animals thriving in urban settings are known to exhibit superior foraging and food extraction abilities compared to their wild conspecifics. This has raised the question regarding if non-human animals can form and maintain a similar “theory of mind” to humans based on the actions they observe in their environments (Schloegl et al., 2007). For this experiment, human-made click and gaze cues were used while placing food for eastern gray squirrels (Sciurus carolinensis) located on the …

Risk Assessment And Flight Decisions In Adult Versus Juvenile Squirrels (Sciurus Carolinensis), Alex Haydon, Jeeva Rathnaweera, Perri Eason

Undergraduate Arts and Research Showcase

One way to quantify a prey’s response to a predator is by flight initiation distance (FID), the distance between a predator and prey at the moment the prey flees. As perceived risk from a predator increases, FID increases. Juvenile animals typically flee from approaching threats sooner than do adults because they have less able risk assessment. However, our observations suggested juvenile squirrels might use a different tactic: foraging near refuges. We first tested whether age affected squirrels’ FID in response to an approaching human on the UofL campus, where squirrels experience high levels of interactions with humans from an early …

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 …

Salmonid Species Diversity Predicts Salmon Consumption By Terrestrial Wildlife, Christina N. Service, Andrew N. Bateman, Megan S. Adams, Kyle A. Artelle, Thomas E. Reimchen, Paul C. Paquet, Chris T. Darimont

Chris Darimont, PhD

1. Resource waves—spatial variation in resource phenology that extends feeding opportunities for mobile consumers—can affect the behaviour and productivity of recipient populations. Interspecific diversity among Pacific salmon species (Oncorhynchus spp.) creates staggered spawning events across space and time, thereby prolonging availability to terrestrial wildlife.

2. We sought to understand how such variation might influence consumption by terrestrial predators compared with resource abundance and intra- and interspecific competition.

3. Using stable isotope analysis, we investigated how the proportion of salmon in the annual diet of male black bears (Ursus americanus; n = 405) varies with species diversity and density of spawning …

Salmonid Species Diversity Predicts Salmon Consumption By Terrestrial Wildlife, Christina N. Service, Andrew N. Bateman, Megan S. Adams, Kyle A. Artelle, Thomas E. Reimchen, Paul C. Paquet, Chris T. Darimont

Habitat and Trophic Ecology Collection

1. Resource waves—spatial variation in resource phenology that extends feeding opportunities for mobile consumers—can affect the behaviour and productivity of recipient populations. Interspecific diversity among Pacific salmon species (Oncorhynchus spp.) creates staggered spawning events across space and time, thereby prolonging availability to terrestrial wildlife.

2. We sought to understand how such variation might influence consumption by terrestrial predators compared with resource abundance and intra- and interspecific competition.

3. Using stable isotope analysis, we investigated how the proportion of salmon in the annual diet of male black bears (Ursus americanus; n = 405) varies with species diversity and density of spawning …

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 …

Gravid Tetragnathid Spiders Show An Increased Functional Response, Mary E. Boswell, John P. Delong

School of Biological Sciences: Faculty Publications

Spiders in the genus Tetragnatha feed on emerging aquatic insects, including mosquitoes and midges, but there is little known about the foraging behavior of these spiders. We hypothesized that female spiders actively developing egg sacs would increase food consumption to provide more energy to produce and provision their eggs. We tested this hypothesis by measuring foraging rates of Tetragnatha spiders kept in jars and provisioned with different levels of midges. We then tested for a difference in the functional response of spiders that did or did not lay egg sacs in their jars. Egg-laying and non-egg-laying spiders showed significantly different …

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 …

Stable Isotopes Reveal Opportunistic Foraging In A Spatiotemporally Heterogeneous Environment: Bird Assemblages In Mangrove Forests, Christina Buelow, April Reside, Ronald Baker, Marcus Sheaves

University Faculty and Staff Publications

Environmental heterogeneity can foster opportunistic foraging by mobile species, resulting in generalized resource and habitat use. Determining species’ food web roles is important to fully understand how ecosystems function, and stable isotopes can provide insight into the foraging ecology of bird assemblages. We investigated flexibility of food choice in mangrove bird assemblages of northeast Australia by determining whether species’ carbon and nitrogen isotopic values corresponded to foraging group classification described in the literature, such as groups of species that are omnivorous or insectivorous. Subsequently, we evaluated foraging group isotopic niche size, overlap, degree of individual specialization, and the probable proportions …

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 …

High-Resolution Archival Tags Provide New Insights Into The Underwater Foraging And Echolocation Behavior Of Resident Killer Whales Capturing Pacific Salmon, Brianna Wright

Salish Sea Ecosystem Conference

Dtags contain sensors for recording both high resolution animal movement and underwater sound. They provide a valuable tool for examining the foraging behavior of resident killer whales, a specialist predator that relies on echolocation to find and pursue Pacific salmon, its primary prey. We deployed Dtags on 32 northern residents off Vancouver Island, BC, and compared reconstructed whale dive paths to distributions of different salmonid prey. Foraging whales dove deeper, remained submerged longer, swam faster, increased their dive path tortuosity, and rolled their bodies more than during other activities. Foraging dive structure also reflected the deeper vertical distribution of Chinook …

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 …

Behavioral Plasticity Across Non-Social Contexts In Female Green Swordtails, Xiphophorus Hellerii, 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 …

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 …

Displaying To Females May Lower Male Foraging Time And Vigilance In A Lekking Bird, Sarah A. Cowles, Robert M. Gibson

School of Biological Sciences: Faculty Publications

Males of many species use courtship behavior to attract mates. However, by doing so males may face the associated costs of increased energetic expenditure, reduced foraging time, and elevated predation risk. We investigated the costs of display in lekking male Sharp-tailed Grouse (Tympanuchus phasianellus). We used lek-wide scan sampling to study how males allocated time among courtship display (‘‘dancing’’), agonism, foraging, and inactivity in relation to female numbers both within and across days. We also addressed the limited attention hypothesis and estimated visual attentiveness by videotaping 13 males and scoring head turns during these different activities. We found that the …

Isotopic Discrimination In The Double-Crested Cormorant (Phalacrocorax Auritus), Elizabeth C. Craig, Brian S. Dorr, Katie C. Hanson-Dorr, Jed P. Sparks, Paul D. Curtis

Brian S Dorr

The diet-tissue discrimination factor is the amount by which a consumer’s tissue varies isotopically from its diet, and is therefore a key element in models that use stable isotopes to estimate diet composition. In this study we measured discrimination factors in blood (whole blood, red blood cells and plasma), liver, muscle and feathers of Double- crested Cormorants (Phalacrocorax auritus) for stable isotope ratios of carbon, nitrogen and sulfur. Cormorants exhibited discrimination factors that differed significantly among tissue types (for carbon and nitrogen), and differed substantially (in the context of the isotopic variation among relevant prey species) from those observed in …

Shifts In Attack Behavior Of An Important Kelp Forest Predator Within Marine Reserves, J. S. Berriman, M. C. Kay, D. C. Reed, A. Rassweiler, D. A. Goldstein, William G. Wright

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Marine reserves have become increasingly valuable tools with which to manage ecosystems. These reserves consistently restore populations of top predators, often reducing availability of their favored prey. We hypothesized that such prey reduction in reserves causes protected predators to alter their attack behavior to include less palatable prey, potentially amplifying top-down effects on community structure. To test this hypothesis, we presented the relatively unpalatable sea hare Aplysia californica to freely foraging spiny lobsters Panulirus interruptus in 4 marine no-take reserves, each paired with an adjacent fished area. We found that lobsters only attacked sea hares inside reserves, where lobster density …