Terrestrial and Aquatic Ecology Commons^™

Role Of Reptile-Invertebrate Interactions In Enigmatic Reptile Declines, Meredith Swartwout

Graduate Theses and Dissertations

Reptile populations are declining world-wide and the mechanisms behind many of these declines remain enigmatic. Food web interactions (i.e., reduced prey availability or increased predation) have been implicated behind some reptile declines. However, relatively little is known about predation on lizard and snake eggs, despite egg survival being important for population dynamics of some species. Ants are important predators of squamate reptile eggs in tropical and temperate systems. In Costa Rica, long-term declines in terrestrial anole lizards were linked with reduced leaf litter depth, a factor that could influence egg vulnerability to ant predation. Fire ants (genus Solenopsis) are aggressive …

Gray Wolves, Eric Gese, John P. Hart, Patricia Terletzky

Wildlife Damage Management Technical Series

Wolf conflicts are primarily related to predation on livestock, pets and other domestic animals, as well as their direct and indirect impacts on native ungulates (i.e., big game). Economic losses vary widely with some livestock producers facing high levels of depredation in some areas. This publication focuses on wolf ecology, damage, and management, particularly as it relates to wolf depredation on livestock and other conflicts with people.

Wolves and people share the same environments more than people realize. In the U.S., wolves are not confined to wilderness areas. Though curious, wolves generally fear people and rarely pose a threat to …

Climate-Driven Impacts On Himalayan Aquatic Biodiversity: A Case Study Involving Snowtrout (Cyprinidae: Schizothorax), Riri Wiyanti Retnaningtyas

Graduate Theses and Dissertations

Monitoring biodiversity, to include its relative dispersal and contraction, has become a conservation task of great importance, particularly given the catastrophic and ongoing loss of habitat due to climate change. However, the timing, direction, and magnitude of these rates vary across taxa and ecosystems. Predicting specific impacts of climate change can thus be difficult and this, in turn, hampers management action. Metrics are needed to not only quantify contemporary requirements of species, but also predict potential distributions that fluctuate in lockstep with climate.

Montane ecosystems in the Himalayas are highly impacted by climate change, yet remain largely understudied due to …

Troglofauna Of Van Buren And White County: A Survey Of Four Caves In The Mideastern Cumberland Plateau, Gavin Page

Honors Theses

The Cumberland Plateau in Tennessee has the highest cave-obligate biodiversity in North America. Cave-obligate species are entirely restricted to subterranean habitat and demonstrate unique troglomorphy. These species are categorized as troglobionts. However, because of their isolated occurrences, theses species are vulnerable to a variety of disturbances. This issue is furthered in the fact that only approximately 7% of the caves in this region have been surveyed. Of these caves that have been surveyed, only a small portion were professional entomological surveys, while almost no cave has ever been extensively repeat sampled. This study involved newly sampling one cave and repeat …

Population Connectivity Of The Eastern Collared Lizard Crotaphytus Collaris In Arkansas, Whitney Allison Murchison-Kastner

Graduate Theses and Dissertations

Habitat reduction and fragmentation can isolate populations and decrease genetic diversity, making them susceptible to local extirpation. Additionally, geographic barriers can further impede dispersal among populations thus reducing gene flow. Field studies suggest these factors may be responsible for the decline in Eastern Collared Lizard (Crotaphytus collaris) populations in Arkansas. To address the impacts of habitat loss and fragmentation on the Eastern Collared Lizard (C. collaris) in Arkansas, I used DNA fragment analysis to examine genetic diversity, population structure and connectivity among C. collaris populations. I do so herein by employing microsatellite data from 138 adults across 11 loci to …

Results Of The Non-Lethal Smart Drumline Trial In South-Western Australia Between 21 February 2019 And 20 February 2021, Department Of Fisheries

Fisheries Occasional Publications

No abstract provided.

Stoichiometry And Parasitism: Changes In Nutrient Concentrations In The Three-Spined Stickleback-Schistocephalus Solidus System, Megan Braat

Honors Scholar Theses

Ecological stoichiometry is a rapidly growing field of study that assesses the elemental composition of organisms in ecosystems and the impact that changes in these elemental compositions have on populations. Parasitism is widely studied for its role in altering the physiology and behavior of hosts within a population. However, the interaction between parasitism and the stoichiometry of the host-parasite system has not been well-established. To determine the impact of parasitism on stoichiometry of host, we measured the elemental composition (%C, %N, and %P) and ratios (C:N, C:P, and N:P) of a population of parasitized and unparasitized Gasterosteus aculeatus (three-spined stickleback) …

Population Genomics Of Invasive Rodents On Islands: Genetic Consequences Of Colonization And Prospects For Localized Synthetic Gene Drive, Kevin P. Oh, Aaron B. Shiels, Laura Shiels, Dimitri V. Blondel, Karl J. Campbell, J. Royden Saah, Alun L. Lloyd, Paul Q. Thomas, Fred Gould, Zaid Abdo, John R. Godwin, Antoinette J. Piaggio

United States Department of Agriculture Wildlife Services: Staff Publications

Introduced rodent populations pose significant threats worldwide, with particularly severe impacts on islands. Advancements in genome editing have motivated interest in synthetic gene drives that could potentially provide efficient and localized suppression of invasive rodent populations. Application of such technologies will require rigorous population genomic surveys to evaluate population connectivity, taxonomic identification, and to inform design of gene drive localization mechanisms. One proposed approach leverages the predicted shifts in genetic variation that accompany island colonization, wherein founder effects, genetic drift, and island-specific selection are expected to result in locally fixed alleles (LFA) that are variable in neighboring nontarget populations. Engineering …

Juvenile Conifer Growth And Regeneration Across Diverse Climatic And Environmental Conditions In The Southwestern United States, Nikki L. Pirtel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Juvenile conifer germination, growth, and survival will play important roles in the persistence of coniferous forests and woodlands in the southwestern United States (SWUS), yet it is unclear how juvenile conifers allocate aboveground and belowground early growth and if growth differs between conifer and ecosystem types. Descriptions of growth characteristics may allude to the types of stress juveniles experience in their environments, how they morphologically respond to stress, and how they may be able to survive stress to persist in their current locations or expand into new areas. In Chapter 1, I described the growth characteristics of 4 juvenile conifer …

Distributions And Habitat Associations Of Blue Point Pyrgulopsis And Blue Point Tryonia, Chenoa Janine Wilcox

UNLV Theses, Dissertations, Professional Papers, and Capstones

Springsnails and other crenophilic species are often of conservation concern due to endemism, narrow habitat requirements, and susceptibility to habitat degradation. Because there is a distinct lack of natural history information for many of these organisms, management of species that are of concern is often based on data from non-target species related to the species of interest. In this thesis, I provide background information regarding springsnails in western North America (Chapter 1), describe a study investigating the distribution and habitat associations of two springsnails endemic to a single spring (Chapter 2), and provide supplemental information on habitat characteristics associated with …

Influence Of Local- And Landscape-Scale Factors On Avian Assemblage In Fragmented Tallgrass Prairie Landscape, Pooja Panwar

Graduate Theses and Dissertations

Agricultural expansion and increasing urbanization are driving rapid landscape modification in the Tallgrass prairies ecosystem and are affecting biodiversity at multiple spatial scales. Thus, the conservation of fragmented grassland and steeply declining grassland avifauna is dependent on the relationship between local- and landscape-scale factors and avian assemblage. We also need to understand how these factors, operating at different spatial scales, drive the occupancy of different guilds in the assemblage. We conducted repeated point count surveys during the breeding season of 2019 at 66 grassland sites across Arkansas and Missouri, USA. We developed a multi-species occupancy model to estimate species richness, …

Characterizing The Relationship Between Species Richness And The Seasonal Phenomenon Of Tropical Fish Dispersal In New England Waters, Michael E. O'Neill

Graduate Masters Theses

The Gulf Stream exerts tremendous influence over oceanographic conditions in the Northwest Atlantic as it transports tropical water to higher latitudes. As the Gulf Stream’s path traverses the east coast of North America, there are implications for the biogeography of marine ecosystems within this range and beyond. While the meandering eddies and warm core rings generated by the Gulf Stream persist year-round, the seasonal warming of New England’s coastal waters afford many tropical species transported by the current temporary residence through the summer and fall. Many aspects that shape this phenomenon and its impact on coastal ecosystems remain a mystery. …

Climate And Soil Moisture Dynamics Inform Potential Climate Change Impacts On Available Moisture And Juvenile Tree Survival In Semiarid Forests, Carolyn R. Koehn

UNLV Theses, Dissertations, Professional Papers, and Capstones

Trees in semiarid forests and woodlands of the western United States need soil moisture to transpire and function. Juvenile trees are especially vulnerable during periods of low soil moisture as their rooting zones are smaller and shallower than those of adult trees. This thesis focuses on two soil moisture-driven aspects of semiarid forests that may be modified by climate change: seasonal soil moisture patterns and juvenile tree survival.

In chapter 1, I investigated the influence of precipitation on soil moisture across seasons, elevations, soil layers, and periods of low and high precipitation. I developed time-varying definitions of winter (snow accumulation), …

Linking Extreme High Air Temperature Events To Wildfire And Environmental Variation To Water Balance Partitioning In The Western Us, Neil Savage

UNLV Theses, Dissertations, Professional Papers, and Capstones

Chapter 1

Wildfire activity has increased across the western United States in recent decades, causing significant damage to ecosystem services and human communities. The Sierra Nevada region, in particular, has experienced substantial increases in the ignition frequency, severity, and extent of large wildfires. To partly disentangle the complex processes underlying wildfire risk, I developed a simple approach to link natural wildfire ignition patterns to changing seasonal temperatures and extreme high and low air temperature events across the Sierra Nevada region from 1992—2015. Extreme event analyses focused on the association between the magnitude and frequency of occurrence of extreme temperature events …

Soil Salinity And The Occurrence Of Invasive Phragmites Australis In Scarborough Marsh, Anthony Devecchis

Thinking Matters Symposium

In North America, Phragmites australis (Cav.) Trin. is a common invasive reed that competes well in wetland ecosystems and wet ditches. According to the Maine Department of Agriculture, Conservation and Forestry’s Natural Areas Program, P. australis is disruptive to both tidal and freshwater marshes throughout Maine, including Scarborough Marsh, the state’s largest salt marsh covering an area of 3100 acres (≈ 1,254 hectares). Like many tidal marshes, Scarborough Marsh plays an important role buffering against high tides and flood waters, whilst providing key habitat for numerous species of fishes, birds, and insects. Previous research suggests that changes in soil …

Feeding Ecology Of Elusive Caribbean Killer Whales Inferred From Bayesian Stable Isotope Mixing Models And Whalers’ Ecological Knowledge, Jeremy J. Kiszka, Michelle Caputo, Paula Méndez-Fernandez, Russell Fielding

Honors College Faculty Publications

Investigating the feeding ecology of marine predators is critical for understanding their roles and functional importance in ecosystems. However, assessing the diet of large and wide-ranging predators can be challenging, particularly in the case of rare and elusive species. Killer whales (Orcinus orca) are large apex predators in global oceans, but very little is known about their feeding ecology in tropical ecosystems, particularly in the Caribbean Sea. Killer whales are distributed throughout the Caribbean, and are a regular target of artisanal whalers in St. Vincent and the Grenadines (West Indies). Here we investigate the feeding ecology of Caribbean killer whales …

Too Little Ph: How Freshwater Acidification Impacts The Abundance Of Macrophytes Consumed By Rusty Crayfish, Lauren Tucker, Paul Moore Dr., Jay Jones Mr.

Honors Projects

Anthropogenic activities such as the burning of fossil fuels result in increased atmospheric carbon dioxide (CO₂) concentration. High levels of atmospheric CO₂ cause chemical shifts in the carbon cycle. Changes in the carbon cycle due to increased CO₂ levels lead to ocean and freshwater acidification. Freshwater acidification is problematic for species that synthesize their own shells as well as species that use olfaction for decision-making. Rusty crayfish (Faxonius rusticus) were subject to simulated freshwater acidification and fed two types of macrophyte, Chara (Chara braunii) and Myriopyllum (Myriophyllum sibiricum). A series …

Decline In Amphibian Health In Local Stream, Elyse Vetter, Elise Dearment, Colton Russell, Audrey Fontes, Lee Kats

Seaver College Research And Scholarly Achievement Symposium

Many local streams of the Santa Monica Mountains are populated by the native California Newt, Taricha torosa, a species of special concern. Arroyo Sequit is one of these streams, the upper and lower portions of which are split by a culvert and the Mulholland Highway. This stream and the surrounding areas burned during the Woolsey fire of 2018. Since the fire, construction has been ongoing in and around the stream. Two years post-fire (during the summer of 2020) significantly more newts were found in the stream than years prior. A large proportion of these newts were unhealthy in appearance, …

Conspecific Aggression Of Invasive Crayfish, P. Clarkii, In Response To Chemical Cues, Elyse Vetter, Elise Dearment, Audrey Fontes, Gary Bucciarelli, Lee Kats

Seaver College Research And Scholarly Achievement Symposium

Red Swamp Crayfish, Procambarus clarkii, have caused vast damage to the stream ecosystem of the Santa Monica Mountains, following their invasive introduction. Through their extensive eating habits, high levels of aggression, and responsiveness to environmental stimuli, P. clarkii have a tremendous impact on the success of native species in the Santa Monica Mountains. With exposure to chemical cues, crayfish are able to perceive threats and react accordingly. To determine the extent of such chemoreception, pairs of P. clarkii were tested in the laboratory for conspecific aggression in the presence of native newt, native frog, and conspecific alarm cues. The …

The Effects Of Symbiote Ostracods On Invasive Crayfish Behavior, Audrey Fontes, Elyse Vetter, Gary Bucciarelli, Lee Kats

Seaver College Research And Scholarly Achievement Symposium

Invasive crayfish, Procambarus clarkii, are known to negatively impact the biodiversity of Santa Monica Mountain streams. Small symbiotes, ostracods, live on Procambarus clarkii in some local streams. However, their effect on the behaviour of invasive crayfish is unknown. We used an aqueous chlorobutanol solution to remove ostracods from crayfish. We paired control crayfish with those that had ostracods removed and scored aggressive interactions. Crayfish without ostracods were found to be significantly more aggressive towards crayfish with ostracods. When we compared feeding behavior, we found that crayfish without ostracods consumed food more quickly than control crayfish. We again subjected crayfish …