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Full-Text Articles in Life Sciences
How Flow Regime Affects Predator-Prey Relationships Of Stream Darter And Shiner Species, Anna E. Richardson
How Flow Regime Affects Predator-Prey Relationships Of Stream Darter And Shiner Species, Anna E. Richardson
Biological Sciences Undergraduate Honors Theses
Analysis of the interactions between abiotic and biotic factors of environments and ecosystems is a highly valued area of research. This study focuses on the interactions between the biotic component of predation and foraging of certain stream fish species and the abiotic component of the flow regime that those species reside in. Gut content analysis followed by statistical calculations in the form of t-tests and chi -quared tests were performed on two fish species who both inhabited a stream with a groundwater flashy flow regime as well as a stream with a runoff flashy flow regime. The research showed that …
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
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
Electronic Theses and 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 …
Bottom-Up Herbivore-Plant Feedbacks Trump Trophic Cascades In A Wolf-Elk-Grassland System, Trevor C. Weeks
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 …
Snowshoe Hare (Lepus Americanus) Abundance In Relation To Habitat And Predator Assemblage Across The Apostle Islands, Jarod Reibel
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 …
Ecosystem Functional Consequences Of Body Size Variation In An Apex Predator (Ambystoma Jeffersonianum), David Samuel Smith
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 …
Population Dynamics Of The Threatened Staghorn Coral, Acropora Cervicornis, And The Development Of A Species-Specific Monitoring Protocol, Elizabeth Goergen
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 …
Predator Presence And Size Variation Alters Community Structure Through Multiple Trophic Cascades, Robin Baker, Howard Whiteman Ph.D.
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 …
Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker
Predicting Suitable Habitat Decline Of Midwestern United States Amphibians And Quantifying The Consequence Of Declines Using Pond-Breeding Salamanders, Brock Struecker
Master's Theses
With current declines of vertebrate taxa meeting or exceeding those of historic mass extinction events, there is a growing need to investigate the main drivers of declines. Amphibians are perhaps at greatest risk of global climate change and land-use changes than most other vertebrate classes and also have significant roles in ecosystem processes – combined, this creates a cause for concern. I designed a study that would investigate the effects of current and predicted climate change and land-use changes on amphibians using species distribution models and a field study to identify the potential consequences of amphibian species declines by investigating …
An Approach For Use Of Dual Frequency Identification Sonar (Didson) To Quantify Behavioral Aspects Of Piscivory At Ecologically Relevant Time And Space Scales, Victoria E. Price
An Approach For Use Of Dual Frequency Identification Sonar (Didson) To Quantify Behavioral Aspects Of Piscivory At Ecologically Relevant Time And Space Scales, Victoria E. Price
Master's Theses
Predator-prey interactions of large vagile fishes are difficult to study in the ocean due to limitations in the space and time requirements for observations. Small-scale direct underwater observations by divers (<10m >radius) and large-scale hydroacoustic surveys (10s - 100s km2) are traditional approaches. However, large piscivorous predators identify and attack prey at the scale of meters to tens of meters. Dual- Frequency Identification Sonar, or DIDSON, is a high-resolution acoustic camera operating in the MHz range that provides detailed continuous video-like imaging of objects out to 30 m range. This technology can be used to observe predator-prey interactions at ecologically …
Vulnerability Of Logfin Inshore Squid (Loligo Pealeii) To Predation: The Influence Of Relative Prey Size And Behavior, Michelle Dana Staudinger
Vulnerability Of Logfin Inshore Squid (Loligo Pealeii) To Predation: The Influence Of Relative Prey Size And Behavior, Michelle Dana Staudinger
Open Access Dissertations
Cephalopods provide forage to a wide range of predators in marine food-webs. Despite their ecological importance, a basic understanding of the mechanisms controlling predation risk and demand is lacking. This is true of one of the most common species of squid found in the northwest Atlantic, the longfin inshore squid (Loligo pealeii). In this dissertation, I address this shortcoming by investigating the role that size and behavior play in influencing squid’s vulnerability to predation. I used long-term food habits, population survey, and commercial landings data, to quantify size-based patterns of predation respective to 25 species of predators. Additionally, I estimated …
The Impact Of Resident And Transient Predators On The Popultation Dynamics Of Juvenile Caribbean Spiny Lobster (Panulirus Argus) In Florida Bay, Florida, Jason Edward Schratwieser
The Impact Of Resident And Transient Predators On The Popultation Dynamics Of Juvenile Caribbean Spiny Lobster (Panulirus Argus) In Florida Bay, Florida, Jason Edward Schratwieser
Biological Sciences Theses & Dissertations
There has been a considerable amount of research devoted to exploring the relationship between predators and prey, but many of these studies fail to address how predation can vary over spatial and temporal scales. The tendency of ecologists to model predation as a static entity often masks its capacity for creating distinctive effects in prey populations and communities. Most predation studies also focus on the effect of a single species of predator on a prey population, an unrealistic situation in nature. In the Florida Keys, juvenile spiny lobsters are subjected to two general classes of predators: i) "resident" predators such …
The Role Of Colonization Predation And Season In Determining Macroinvertebrate Community Structure In A Temperate Lake, Cheryl Lynn Frew
The Role Of Colonization Predation And Season In Determining Macroinvertebrate Community Structure In A Temperate Lake, Cheryl Lynn Frew
Biological Sciences Theses & Dissertations
Field experiments were conducted to examine the effects of distance from shore, vertebrate predation, and season on macroinvertebrate colonization dynamics in a temperate lake in Suffolk, VA. In a year-long colonization study, artificial plants, half of which were caged to exclude vertebrate predators, were deployed in patches at three distances from shore (2m, 15m, 50m). Artificial plant subsamples were removed at weekly intervals over 28 days during four seasons to monitor colonization by macroinvertebrates. Colonization of artificial plants occurred more quickly in the summer and spring than in fall and winter. The interactive effect of distance from shore and cage …