Ecology and Evolutionary Biology Commons^™

Assessing Habitat Suitability Of Ribbed Mussels (Geukensia Demissa) In Georgia Salt Marshes By Examining Predicted Mussel Densities And Mussel Population Parameters, William K. Annis Jr

College of Graduate Studies: Theses & Dissertations

Geukensia demissa (ribbed mussel) is an ecology important bivalve that has the potential to contribute to salt marsh restoration. Understanding the factors that contribute to the distribution of mussels can help inform managers on choosing locations to optimize the survivorship of mussels in restoration projects. This study sought to model mussel densities across the coast of Georgia and to compare predicted mussel densities with mussel population parameters as means to gauge habitat suitability. Mussel densities were collected through field surveys across a range of salt marshes along the coast of Georgia and were compared with spatial data such as distance …

Factors Influencing Survival Rates Of Pronghorn Fawns In Idaho, Brett R. Panting, Eric M. Gese, Mary M. Conner, Scott Bergen

United States Department of Agriculture Wildlife Services: Staff Publications

Pronghorn (Antilocapra americana) occur throughout western North America. In Idaho, USA, following intensive hunting to reduce crop depredations in the late 1980s, pronghorn populations have not rebounded to desired levels. Because neonatal survival in ungulates is one factor limiting population growth, we evaluated cause‐specific mortality and the influence of intrinsic and extrinsic factors on survival rates of 217 radio‐collared pronghorn fawns across 3 study areas in Idaho during 2015–2016. For intrinsic variables, we determined the sex and body mass index (BMI) for each fawn. For extrinsic variables, we determined the abundance of predators and alternate prey, estimated the …

Coyotes, Rick Tischaefer

Wildlife Damage Management Technical Series

The coyote (Canis latrans; Figure 1) is a medium-sized member of the canid family. Once primarily found in western deserts and grasslands, coyotes have expanded their range across North America and into diverse habitats, including urban areas. This expansion occurred during a time of extensive habitat change and efforts by people to suppress coyote populations to prevent damage. Coyotes can cause a variety of conflicts related to agriculture, natural resources, property, and human health and safety. This document highlights a variety of methods for reducing those conflicts. Coyotes are a highly adaptable species and may become habituated to some management …

Distribution And Activity Patterns Of Large Carnivores And Their Implications For Human–Carnivore Conflict Management In Namibia, Summer Fink, Richard Chandler, Michael Chamberlain, Steven Castleberry, Shannon Glosenger-Thrasher

Human–Wildlife Interactions

Human–wildlife conflicts (HWCs) are increasing globally and contributing to the decline of wildlife species. In sub-Saharan African countries such as Namibia, most of the suitable land has been or is currently being converted to crop and livestock production to support income or subsistence agriculture. These changes in land use often incur increased levels of HWCs because of crop and livestock depredation by native species. To quantify livestock predation risks posed by carnivores in Namibia, we deployed 30 trail cameras on a 6,500-ha farm in the Khomas region of Namibia from May to July 2018. We developed occupancy models to make …

Effects Of Freshwater Crayfish On Influenza A Virus Persistence In Water, J. Jeffrey Root, Jeremy W. Ellis, Susan A. Shriner

United States Department of Agriculture Wildlife Services: Staff Publications

Several investigations have recently assessed the ability of some aquatic invertebrates to act as tools for avian influenza A virus (IAV) surveillance as well as their potential role(s) in IAV ecology. Because of this, as well as the high IAV seroprevalence rates noted in select mesocarnivores that commonly inhabit aquatic and semi-aquatic habitats, we evaluated the effects that freshwater crayfish have on IAV in water at three dose levels and monitored for the presence of IAV in crayfish tissues (gill and green gland) and haemolymph at multiple time points. At relatively high, medium 432 and low (approximately 10 , 10 …

Temporal Factors Affecting Foraging Patterns Of A Diurnal Orb-Weaving Spider, Micrathena Gracilis (Araneae: Araneidae), Mitchell Davis Long

Undergraduate Honors Theses

Several studies have investigated the ecological factors that affect behavior in Micrathena gracilis, a diurnal orb-weaving spider that forages on flying insects during the day. However, none yet have considered how the temporal distributions of prey and predator occurrences shape their daily behavioral rhythms, especially web construction, which involves a heavy energetic investment well in advance of potential nutritional benefit. Recently, several orb-weaving spider species have been shown to exhibit a variety of abnormal rhythms, suggesting that circadian clock-controlled rhythms may play an unexpected role in behavioral evolution. Despite the appearance of significant insect abundance in the evenings, M. gracilis …

Spider Prey Of Mud-Dauber Wasps In Southeastern Nebraska, Earl Agpawa, Tyler Corey, Eileen Hebets

UCARE: Research Products

Predator-prey interactions between organisms provide a window into behaviors, adaptions, and evolutionary histories of both groups. One group of organisms of would be female spider-specialist mud-dauber wasps (Hymenoptera: Sphecidae) who seek out and sting spiders to bring back to their nests for their larvae to feed upon. This interaction provides a unique means of quantifying the diversity and abundance of the prey they capture. In this study, we inventoried spiders from within collected nests of mud-dauber wasps Sceliphron caementarium (Drury) and Chalybion californicum (Saussure) from agricultural land and in a forest corridor. It was found that nests collected in agricultural …

Common Ravens, Luke W. Peebles, Jack O. Spencer Jr.

Wildlife Damage Management Technical Series

Damage Management Methods for Common Ravens

Type of Control -- Available Management Options

Exclusion -- Often ineffective or impractical

Fertility Control -- None available

Frightening Devices -- Effigies • Pyrotechnics and propane cannons • Lasers and flashing lights

Habitat Modification -- Bale and bury garbage • Install dumpsters with secure lids • Remove or bury dead livestock • Remove abandoned houses, sheds, and barns to eliminate nesting structures

Nest Treatment -- Allowed with proper Federal and State permits; Egg oiling or addling and nest destruction

Repellents -- Methiocarb (EPA Reg. No. 56228-33) • Methyl anthranilate (food-grade grape flavoring agent)

Shooting …

Bottom-Up Herbivore-Plant Feedbacks Trump Trophic Cascades In A Wolf-Elk-Grassland System, Trevor C. Weeks

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Top-down predator-prey effects that alter the abundance, biomass, or productivity of a population community across more than one link in a food web are referred to as trophic cascades. While these effects have been extensively studied in aquatic environments, fewer studies have examined trophic cascades in terrestrial ecosystems. And fewer still terrestrial studies have tested for trophic cascades between vertebrates and grassland vegetation. Across the globe, grassland plant biomass is driven by both precipitation and non-linear positive feedbacks between grazing and plant productivity, as predicted by the Intermediate Grazing Hypothesis. Yet little is known about the role that apex carnivores …

Trade-Offs Between Morphology And Thermal Niches Mediate Adaptation In Response To Competing Selective Pressures, Stella F. Uiterwaal, Ian T. Lagerstrom, Thomas M. Luhring, Miranda E. Salsbery, John P. Delong

School of Biological Sciences: Faculty Publications

Abstract

The effects of climate change—such as increased temperature variability and novel predators—rarely happen in isolation, but it is unclear how organisms cope with multiple stressors simultaneously. To explore this, we grew replicate Paramecium caudatum populations in either constant or variable temperatures and exposed half to predation. We then fit thermal performance curves (TPCs) of intrinsic growth rate (r_max) for each replicate population (N = 12) across seven temperatures (10°C–38°C). TPCs of P. caudatum exposed to both temperature variability and predation responded only to one or the other (but not both), resulting in unpredictable outcomes. These changes in …

Predator-Based Selection And The Impact Of Edge Sympatry On Components Of Coralsnake Mimicry, Lauren E. Wilson

College of Graduate Studies: Theses & Dissertations

Studying warning coloration and mimicry is an effective way to understand predator-driven selection and phenotypic diversity. The presence (sympatry) or absence (allopatry) of a toxic model plays a role in shaping mimetic phenotypes. However, the impact of edge sympatry and allopatry on predation of mimetic phenotypes is not well understood. We studied coralsnake mimicry to test how edge sympatry and allopatry affect predation on mimetic phenotypes. Specifically, we tested 1) if overall attack rates varied with edge sympatry of coralsnakes 2) which color patterns conferred a fitness advantage 3) which specific mimetic signal components are important in driving predatory attacks …

Estimates Of Calf Survival And Factors Influencing Roosevelt Elk Mortality In Northwestern California, Erin Nigon

Cal Poly Humboldt theses and projects

Survival of juvenile ungulates is known to be highly variable, yet it is fundamental to understanding the dynamics and trends of wildlife populations. Factors influencing calf survival are poorly understood in northwestern California where Roosevelt elk (Cervus canadensis roosevelti) are known to exist. The objectives of this study were 1) to estimate summer and annual survival rates and determine recruitment rates for Roosevelt elk calves in the area, 2) to evaluate differences in calf survival by examining the effects of individual and population level covariates on summer and annual calf survival, 3) to identify factors influencing the timing …

Snowshoe Hare (Lepus Americanus) Abundance In Relation To Habitat And Predator Assemblage Across The Apostle Islands, Jarod Reibel

Masters Theses

Snowshoe hares (Lepus americanus) are a climate sensitive species that have a southern range boundary moving northward. Snowshoe hares are found on the Apostle Islands, Wisconsin which are near their southern boundary and differ by island in vegetative and carnivore communities. The archipelago serves as a natural laboratory to assess how top-down and bottomup forces interact and impact snowshoe hare populations. The objectives of this study were to determine the influence of vegetative characteristics, specifically visual obstruction, and the presence of predators on snowshoe hare abundances across the Apostle Islands. We conducted fecal pellet surveys to estimate hare abundance, measured …

Territorial Behavior Of The Ozark Zigzag Salamander, Plethodon Angusticlavius, Altered By Mode Of Predator Cue And Sex Of Intruder, Sarah E. Heimbach

Graduate Theses/Dissertations

Territorial defense in many species must be balanced with trade-offs in activities such as reproduction and predator avoidance. Adjusting behavior based on current assessments of predation risk and the cost of maintaining or gaining a territory is one way that individuals can balance trade-offs to maximize fitness. I conducted two experiments to determine how Ozark zigzag salamanders, Plethodon angusticlavius, adjust their territorial behavior-based predation risk. First, I tested whether male and female territorial intruders changed their competitive behavior according to whether predation risk is assessed via unimodal (chemical) or multimodal (chemical + physical) cues. Females and males responded differently to …

Using Molecular Diet Analysis To Inform Invasive Species Management: A Case Study Of Introduced Rats Consuming Endemic New Zealand Frogs, Bastian Egeter, Cailín Roe, Sara Peixoto, Pamela Puppo, Luke J. Easton, Joana Pinto, Phillip J. Bishop, Bruce C. Robertson

Biological Sciences Faculty Research

The decline of amphibians has been of international concern for more than two decades, and the global spread of introduced fauna is a major factor in this decline. Conservation management decisions to implement control of introduced fauna are often based on diet studies. One of the most common metrics to report in diet studies is Frequency of Occurrence (FO), but this can be difficult to interpret, as it does not include a temporal perspective. Here, we examine the potential for FO data derived from molecular diet analysis to inform invasive species management, using invasive ship rats (Rattus rattus) …

Comparing Feeding Accuracy Between High And Low Predation Trinidad Guppies, Lydia J. Bonnell

Honors College Theses

Efficient feeding accuracy could increase an organism’s survival. Although local adaptation in Trinidad guppies is common, the effects on accuracy are unknown. Guppies were wild caught in 2015 and 2017, filmed while capturing prey. Accuracy wasn’t different within samples but differed across samples, possibly due to the prey types used.

Ecosystem Functional Consequences Of Body Size Variation In An Apex Predator (Ambystoma Jeffersonianum), David Samuel Smith

Online Theses and Dissertations

Biodiversity is often emphasized at the species level where each species is assigned a mean functional trait value. However, populations within a species, and individuals within a population, often exhibit considerable intraspecific functional variation. Therefore, instead of focusing on species’ mean trait values, we must incorporate intraspecific variation when considering species’ ecological roles and conservation values. The primary objective of this study was to determine the effects of variation in body size (a functional trait in many aquatic taxa) in an apex predator on ecosystem functioning. We sought to characterize trophic cascades initiated by larval populations of Ambystoma jeffersonianum that …

Spatial Associations Of Livestock Guardian Dogs And Domestic Sheep, Julie Young, John P. Draper, Daniel Kinka

Human–Wildlife Interactions

Livestock guardian dogs (Canis lupus familiaris; LGDs) have been used for centuries to protect livestock, primarily domestic sheep (Ovis aries), from depredation by large carnivores. While previous studies have shown their efficacy, the mechanisms in which LGDs protect livestock have largely remained unstudied. Livestock guardian dogs are often considered to be effective only if they remain in spatial proximity to the livestock they are protecting. We determined space use of LGDs relative to domestic sheep on open-range grazing allotments used by working ranches in the Rocky Mountains area of the northwest United States between August 2012 …

Eternal Enemies, Or Incidental Encounters? Structure And Patterns Of Interspecific Killing In Carnivora, Tor G. Bertin

Theses and Dissertations

Lethal interactions between carnivorans (interspecific killing) may influence their population dynamics, behavior, and other important aspects of their ecology. In this study, I expand upon previous research on the broad-scale patterns of interspecific killing in Carnivora (Palomares & Caro 1999, Donadio & Buskirk 2006) with a greatly expanded dataset (inclusion of scat and stomach data and more intensive sampling of the literature), and suggest avenues for future research. While like previous studies, I found a positive effect of relative body size between killer species and killed species on the likelihood of forming a killing interaction, I failed to find evidence …

The Nesting Ecology Of Woodpeckers In The Eastern Cascades And Their Interactions With Nest Competitors And Predators, Samuel D. Cowell

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Woodpeckers create nesting cavities for other birds and animals in forests. This creates dynamic interactions between both woodpeckers and these other animals. Using video cameras, we documented direct behavioral interactions between nesting woodpeckers and other animals in the Eastern Washington Cascades during the 2015 and 2016 breeding seasons. Additionally, we offered 937 students in a General Biology laboratory course to participate in this original research opportunity and described and the impact the experience had on the participants as well as the researchers.

In 2015, Western Blubebirds took over two active Black-backed Woodpecker nests by physically attacking the woodpeckers. In 2016, …

Predators Modify The Temperature Dependence Of Life-History Trade-Offs, Thomas M. Luhring, Janna M. Vavra, Clayton E. Cressler, John Delong

School of Biological Sciences: Faculty Publications

Although life histories are shaped by temperature and predation, their joint influence on the interdependence of life-history traits is poorly understood. Shifts in one life-history trait often necessitate shifts in another—structured in some cases by trade-offs— leading to differing life-history strategies among environments. The offspring size–number trade-off connects three traits whereby a constant reproductive allocation (R) constrains how the number (O) and size (S) of offspring change. Increasing temperature and size-independent predation decrease size at and time to reproduction which can lower R through reduced time for resource accrual or size-constrained fecundity. We investigated how O, S, and R in …

Population Dynamics Of The Threatened Staghorn Coral, Acropora Cervicornis, And The Development Of A Species-Specific Monitoring Protocol, Elizabeth Goergen

HCNSO Student Theses and Dissertations

Historically, Acropora cervicornis was found in high densities on many Caribbean, Florida, and Gulf of Mexico reefs. A disease outbreak in the late 1970s and 80s caused up to 99% loss of A. cervicornis cover at some sites, leaving populations sparsely distributed throughout its range and typically found as isolated colonies. Even though populations are depauperate causing a decrease in sexual reproduction, its fast growth rate and ability to reproduce through asexual fragmentation affords this species the potential for quick recovery and population growth. However, limited to no natural recovery has been documented. Many of these populations are poorly studied …

Competition And Predation: Interactions Between American Eels (Anguilla Rostrata) And Brook Trout (Salvelinus Fontinalis) In Virginia Mountain Streams, Jonathan Studio

Masters Theses, 2010-2019

Competition has played a large role in structuring natural communities, especially with regards to vulnerable organisms. Brook trout and American eel populations have declined in the Mid-Atlantic Region of the United States as a result of anthropogenic development around freshwater ecosystems, and thus, subsequent conservation efforts of both species have included habitat restoration. Conservation efforts have increased the co-occurrence of these predatory fish species that are known to require similar resources. The main objective of this research was to elucidate the potential for competition between brook trout and American eels through analysis of their preferred prey, diet overlap, and supplementary …

An Historical Overview And Update Of Wolf-Moose Interactions In Northeastern Minnesota, L. David Mech, John Fieberg, Shannon M. Barber-Meyer

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Wolf (Canis lupus) and moose (Alces americanus) populations in northeastern Minnesota, USA, have fluctuated for decades and, based on helicopter counts, moose numbers declined to a new low from 2006 to about 2012. Other steep declines were found in 1991 and 1998 during periods when moose counts were done with fixed-wing aircraft; these declines also appeared to be real. Winter wolf numbers, monitored in part of the moose range, had been increasing since about 2002 to the highest population in decades in 2009. However, from 2009 to 2016, wolves decreased precipitously, and the moose- population decline leveled …

Predator Presence And Size Variation Alters Community Structure Through Multiple Trophic Cascades, Robin Baker, Howard Whiteman Ph.D.

Murray State Theses and Dissertations

Predation plays a crucial role in shaping community structure and can initiate trophic cascades that can alter abundances across adjacent trophic levels. Recent research has suggested that variation among individual predators may have stronger effects on ecological dynamics than previously appreciated. Intraspecific variation within predators could lead to differential levels of top-down control with implications for trophic cascade strength. In this experiment, we manipulated the body size variation of predatory mole salamanders (Ambystoma talpoideum) within experimental mesocosms and monitored a suite of abiotic and biotic response variables. We predicted that predator populations with increased body size variation would …

Life On The Edge: Risk Of Predation Drives Selection Of Habitat And Survival Of Neonates In Endangered Sierra Nevada Bighorn Sheep, Shannon Forshee

Graduate Student Theses, Dissertations, & Professional Papers

Long-term viability of endangered populations requires development of effective management strategies that target the population vital rate with the highest potential to influence population trajectories. When adult survival is high and stable, juvenile recruitment is the vital rate with the greatest potential to improve population trajectories. For my thesis I examined how lactating Sierra Nevada Bighorn sheep (Ovis Canadensis sierra) balance forage and predation risk during the neonatal period. I first identified resource selection strategies employed by lactating females to promote survival of neonates and then determined the primary factors affecting survival of neonates. I found lactating females selected for …

Predation On Artificial Turkey Nests At Radford Army Ammunition Plant In Western Virginia, Shane Brandes, Karen E. Powers, Len L. Diioia Jr.

Virginia Journal of Science

Because ground-nesting wild turkeys (Meleagris gallopavo) may sustain high incidences of nest predation in western Virginia, determining their predators is essential to understanding risk and managing the birds.  Our study investigated potential predators of wild turkey nests at the Radford Army Ammunition Plant, New River Unit (RFAAP; Pulaski Co., in western Virginia). Here, we established 8 artificial nests during the breeding season for wild turkey (March-April, 2017), and documented predators via game cameras.  Thirty-one species of mammals and birds visited the nests over the 31-day study. Nest predation was verified 56 times across 6 species, including coyotes ( …

Humans As Prey: Coping With Large Carnivore Attacks Using A Predator-Prey Interaction Perspective, Vincenzo Penteriani, Giulia Bombieri, José María Fedriani, José Vicente López-Bao, Pedro José Garrote, Luca Francesco Russo, María Del Mar Delgado

Human–Wildlife Interactions

The number of attacks on humans by large carnivores in North America is increasing. A better understanding the factors triggering such attacks is critical to mitigating the risk of future encounters in landscape where humans and large carnivore co-exist. Since 1955, of the 632 attacks on humans by large carnivores, 106 (17%) involved predation. We draw on concepts and empirical evidence from the Predator-Prey Interaction Theory to provide insights into how to reduce predatory attacks and, thus, improve human-large carnivore co-existence. Because large carnivore-caused mortality risks for humans are comparable to those shown by other mammal species in response to …

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 …

Nutritional Plasticity In Gray Treefrogs: Interactions Between Competition And Predation Threat, Troy C. Neptune, Sarah S. Bouchard

Undergraduate Honors Thesis Projects

Anurans utilize digestive tradeoffs to best survive in their environment, often in response to competition and predation pressure. In some larval anurans, intraspecific competition induces longer guts, providing a digestive advantage under limiting resources. However, predation threat can induce deeper tails and associated shorter guts in larvae. The purpose of this study was to describe nutritionally plastic responses of larval eastern gray treefrogs, Hyla versicolor, reared with simultaneous environmental stressors: predation and competition. Specifically, we asked if larval guts lengthen to increase digestive efficiency or will tail morphology change to better evade predators? H. versicolor larvae were reared in …