Ecology and Evolutionary Biology Commons^™

Rangewide Migratory Connectivity And Migration Ecology In Swainson's Warblers (Limnothlypis Swainsonii) Derived From Multisensor Geolocators, Garrett Rhyne

LSU Master's Theses

Successful conservation of Neotropical migratory passerines requires a detailed understanding of their annual cycle ecology, including wintering and breeding distributions, migratory pathways and stopovers, and migratory phenology. It is also important to evaluate the extent of geographic isolation between separate breeding populations during the nonbreeding season, known as migratory connectivity. Swainson’s Warbler (Limnothlypis swainsonii) is a species of conservation concern that, due to their secretive nature and selection of dense forest habitats, is poorly studied and lacks migratory information. Our objective was to track Swainson’s Warblers across their breeding populations (Mississippi Valley, Coastal Plains, and Appalachian) to detail …

Assessing The Effects Of Live Oysters And Sampling Gear On Biodiversity Metrics Of Reef-Associated Benthic And Nekton Assemblages, Finella Campanino

LSU Master's Theses

Oysters are declining globally, resulting in an increase in oyster reef restoration, with many efforts prioritizing maintenance of reef-associated biodiversity. Understanding the role that reef-specific characteristics play in supporting biodiversity and how sampling gear influences measurements of biodiversity can inform design and management of restoration projects. I examined the relationship between live oyster volume and reef-associated benthic and nekton assemblages (hereafter reef assemblages) and how sampling gears influence our understanding of biodiversity on intertidal Crassostrea virginica reefs near Cocodrie, Louisiana. I quantified substrate characteristics, assemblages via trays, and water-column characteristics across four reefs and four seasons in 2022-2023, and compared …

Wave Attenuation Through Mangrove Forest Using Lidar Representation, Elizabeth Bogan

LSU Master's Theses

Mangrove forests can be found along the world’s intertidal tropical and sub-tropical coastlines. These forested wetlands provide many ecosystem services, including supporting coastal food chains, trapping sediment, and shoreline stabilization. Mangroves are also known for flood damage mitigation by dissipating waves and surge during flooding events. Thus, coastal communities declare a vested interest in the performance of the forest to mitigate flood damage. Physical models using artificial mangrove structures have shown that red mangrove-dominated fringe forests can protect built infrastructure by reducing wave height due to increased drag. One way to estimate the contribution of red mangrove (Rhizophora mangle) prop …

Reef Fish Movement Dynamics And Recruitment To Artificial Habitat, Jade Carver

LSU Master's Theses

Artificial reefs provide critical habitat for fish in areas lacking benthic structure, yet our understanding of how artificial reefs function and develop is limited. Here, changes in reef fish community assemblages were monitored using baited remote underwater video (BRUV) surveys (n=6) before and after a new artificial reef was deployed. Movement of red snapper (Lutjanus campechanus, n=20) and gray snapper (Lutjanus griseus, n=20) between nearby platforms (n=3) and the new artificial reef was examined using acoustic telemetry, and residency was calculated for fish associated with platforms and the artificial reef …

Impact Of Sediment Diversion For Coastal Restoration On Nitrogen And Phosphorus Biogeochemical Cycling In Coastal Louisiana, Usa, Mercedes M. Pinzon Delgado

LSU Master's Theses

Wetlands provide essential ecosystem services and functions, including improving surface water quality through nutrient removal. Louisiana experienced ~4,800 km² of coastal wetland loss between 1932 and 2016 due to high relative sea level rise and reduced sediment input from the Mississippi River (MR). The 2023 Louisiana Coastal Master Plan aims to restore Louisiana's degraded coastline through restoration projects, including sediment diversions. The Mid-Barataria Sediment Diversion project will reconnect MR sediment-laden water with Barataria Basin degrading marshes. The diversion will also deliver nitrate (NO₃^-) and soluble reactive phosphorus (SRP) to this basin, potentially negatively impacting water quality. …

Tracing Energy Pathways Through Coastal Wetland Food Webs, Katherine Loesser

LSU Master's Theses

Southeastern Louisiana’s coastal wetlands are important habitat for aquatic species, yet the spatial heterogeneity in habitat types and abundance of many basal energy sources makes it challenging to elucidate patterns of energy flow across the landscape mosaic. This ecosystem is experiencing substantial changes, both through anthropogenically-accelerated climate change and anthropogenic landscape modifications. Therefore, the overall goal of this thesis was to trace patterns of energy flow across coastal wetland landscapes to determine which basal energy pathways support aquatic food webs and if patterns of energy pathway dependence are altered by changes to the landscape. In the first part of this …

Silica Concentrations In Dominant Vegetation Species Of Wax Lake Delta, Louisiana, Danielle M. Soileau

LSU Master's Theses

Coastal deltaic wetlands colonize dynamic environments and experience fluctuations of salinity, river connectivity, sediment dredging or deposition, and periods of inundation resulting in unique vegetation and soils. Louisiana’s coastline is experiencing enhanced loss of coastal deltaic wetlands in coastal basins where the Mississippi River no longer is connected to waterways and channels that would normally provide freshwater and sediments representing the abandonment phase of the delta cycle. There is a coastal basin in the central regions of the state, the Atchafalaya Bay, that is still in the active phase of delta cycle resulting in the growth of the Wax Lake, …

Evaluating Abiotic And Biotic Factors Affecting Plant Succession Processes At Malheur Lake, Beth Boos, Sammy L. King

LSU Master's Theses

Arid wetlands are diverse systems that provide habitat for a variety of flora and fauna, including stopover and breeding habitat for migratory birds. In the western United States, these wetlands support a network of stopover sites on the Pacific Flyway, and due primarily to wetland loss and alterations, these areas are becoming more isolated. Malheur Lake is a shallow endorheic lake in eastern Oregon that supported a robust emergent marsh throughout most of the 20^th century. However, following large scale flooding in the 1980s, emergent vegetation was extirpated and has only reestablished in small patches. Our objective was to …

Evaluation Of Reproductive Phenology, Space Use, And Ecology Of The Eastern Wild Turkey (Meleagris Gallopavo Silvestris) In West-Central Louisiana, Chad Argabright

LSU Master's Theses

Nest site selection is a driving demographic force behind eastern wild turkey (Meleagris gallopavo silvestris) populations. However, previous research was likely not focused on the actual time of nest site selection, considering that nest site selection is likely only able to occur on the day of the first egg being laid. My objective was to determine if selection for any vegetation characteristics was occurring on the first day of laying. I estimated the path taken from the roost to the nest on the first day of egg laying (i.e., laying path) using GPS data collected from 164 unique …

Controls Of Physical Drivers On The Formation And Toxicity Of Harmful Cyanobacteria Blooms (Cyanohabs), Courtney N. Hammond

LSU Master's Theses

Estuaries within the Gulf of Mexico are exhibiting profound alterations due to climatic changes and the implementation of coastal restoration activities. These changes are attributed to the increasing frequency of harmful cyanobacteria blooms (cyanoHABs) within Lake Pontchartrain, an estuary located in southeastern Louisiana, USA. There is a better understanding into how the opening of the Bonnet Carré Spillway (BCS) impacts cyanoHAB formations compared to the effect of other physical drivers when the spillway doesn’t dominate the system. The goal of this study is to provide a greater understanding of the baseline conditions when the BCS is closed and determine what …

History, Annotated Gazetteer, And Bibliography Of Sarawak Ornithology, Frederick H. Sheldon, Dency F. Gawain, Daisy G. S. Kho, Rosalina Regai, Subir B. Shakya, Chin Aik Yeap

Occasional Papers of the Museum of Natural Science, Louisiana State University

Sarawak is Malaysia’s largest state, covering most of northern Borneo. It has a remarkable history of scientific bird study, starting in the 1840s and growing ever since. To set the stage for the gazetteer, which is the core of this paper, we start with a review of this history and discuss various forces that have influenced the direction of bird research in the state. Following this introduction comes the gazetteer, which is an annotated list of c. 865 sites in Sarawak where birds have been collected, studied, or regularly observed. The gazetteer provides the latitude, longitude, and elevation of each …

Effects Of Riverine Barriers On Avian Evolution In The Amazon Basin, Andre Eugene Moncrieff

LSU Doctoral Dissertations

The high biodiversity found in the Amazon Basin has long captivated the attention of naturalists and evolutionary biologists seeking to explain its origins. Early observations by Alfred Wallace highlighted the role of rivers in delimiting the geographic ranges of many species; furthermore, where rivers narrow towards their headwaters, he noted that some species cross rivers freely. A major goal of this dissertation is to investigate how these and other observations about riverine barriers might inform our understanding of how speciation unfolds in Amazonia. My approach involved generating genomic data with dense geographic sampling for manakins in the genus Lepidothrix, …

A Subspecies-Level Database Of Amazonian Bird Distributions, With Inferences On Suture Zones And Conservation, Marco Antonio Rego

LSU Doctoral Dissertations

Amazonia has the largest and most biodiverse tropical forest on the planet. However, the distributions of its species are still poorly understood, even for well-studied vertebrates such as birds. Available distribution maps for Amazonian birds often lack accuracy in delimiting the area where species occur. Existing distributional information for Amazonian birds is often limited to species-level level taxonomy, even though many Amazonian bird subspecies represent biological species. Here, I investigate the geographic distributions of 4,148 bird taxa (species and subspecies) using museum scientific specimens as the primary source of data. To build the data base I use more than 600,000 …

Understanding Community Assembly Processes Of Foundation Species Within Hyper-Diverse Ecosystems, Carrie Barker

LSU Doctoral Dissertations

Foundation species provide the structure for other species and can significantly affect the composition and overall diversity within a community. Multiple foundation species can coexist within a community, and each can have differential impacts. My dissertation aims to understand the effects different foundation species have on diversity and the community assembly processes responsible for structuring diversity within their respective communities.

First, I quantified the diversity of groundcover plants within the prominent foundation species, bunchgrasses, (dominated by Shizachyrium scoparium) compared to groundcover plant diversity within patches of the alternative foundation species bracken fern (Pteridium aquilinum) and gallberry ( …

Characterizing Habitat Suitability For Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) In Southern Louisiana, Jenna N. Brogdon

LSU Master's Theses

A generalized additive modeling (GAM) framework was used to characterize fish-habitat relationships and develop habitat suitability maps to predict spatiotemporal and ontogenetic shifts in Gulf sturgeon distribution within an impacted estuary in the northern Gulf of Mexico, Lake Pontchartrain. Gulf sturgeon (n = 103) were fitted with acoustic transmitters in the Pearl River during the early summer and fall from 2013 to 2018, and an array of acoustic receivers (n = 81) was used to monitor Gulf sturgeon habitat use and movement in the estuary from 2016 to 2019. Daily presence data from the telemetry array were paired with environmental …

Wetland Soil Development Along Salinity And Hydrogeomorphic Gradients In Active And Inactive Deltaic Basins Of Coastal Louisiana, Amanda Fontenot

LSU Master's Theses

Coastal wetlands provide an abundance of ecosystem services that benefit society, such as essential habitat for commercial species, storm protection, nutrient cycling, and carbon storage. Louisiana faces rapid rates of relative sea level rise (natural subsidence and eustatic sea levels) that threaten wetland survival, which are amplified by a reduction of riverine sediment input. An important determining factor of marsh survival is the formation of wetland platform elevation, known as vertical accretion, which is determined by several processes including sediment deposition & erosion, below ground biomass (BGB) productivity, decomposition of organic matter, shallow & deep subsidence, and soil compaction. Feldspar …

Evolution Of Freshwater Fishes In The Northern Neotropics, Diego Elias

LSU Doctoral Dissertations

The northern Neotropics (NN) represents one of the most geologically-complex regions on the planet, composed of island-like geological blocks that have undergone multiple episodes of isolation and connectivity at various geological times. The riverscapes of the NN harbor a unique assemblage of freshwater fishes. In contrast to the freshwaters systems of South America, which are dominated by ostariophysan lineages, the aquatic systems of the NN are dominated by lineages of two families: Cichlidae (cichlids) and Poeciliidae (livebearers). It has been suggested that the geologically complex nature of the region allowed ancestors of cichlids and livebearers to colonize and radiate within …

Insights Into The Speciation Process From Genomic And Phenotypic Analysis Of An Avian Hybrid Zone In Amazonia, Glaucia Christina Del-Rio

LSU Doctoral Dissertations

Understanding the outcome of secondary contact is essential to shed light on the mechanisms governing species formation and maintenance. In Amazonia, closely related bird taxa with limited dispersal abilities are often separated by rivers, which presumably act as dispersal barriers. However, at the headwaters, rivers cease to be dispersal barriers, and this generates opportunities for secondary contact. In my dissertation, I studied genomic mechanisms associated with phenotypic differences, mitochondrial DNA structure, and putative reproductive barriers between two hybridizing Amazonian bird species in the genus Rhegmatorhina, a group of antbirds that find their arthropod prey exclusively by following army-ant swarms. …

Breeding Ecology Of Mottled Ducks In Southwestern Louisiana, Elizabeth Sophia Bonczek

LSU Doctoral Dissertations

Mottled ducks are a resident species found in the southern United States that rely on coastal marsh and associated habitat to fulfill the needs of the entirety of their annual cycle. Population monitoring has revealed declines in western Gulf Coast (WGC) mottled ducks since 2008. Mottled duck populations are influenced by survival and recruitment, and changes in these factors may contribute to population declines. The overarching goal of this project was to identify the mechanisms potentially limiting WGC mottled ducks.

I captured adult female mottled ducks during molt on Rockefeller Wildlife Refuge and adjacent lands in southwestern Louisiana from 2017–2019. …

Plastic And Evolved Responses In The Eastern Oyster, Crassostrea Virginica, To Environmental Variation In The Northern Gulf Of Mexico, Kyle Sirovy

LSU Doctoral Dissertations

Climate change and other anthropogenic impacts are causing rapid alterations to many of the world’s most productive coastal ecosystems and there is an urgent need to understand how species will respond to these environmental changes. Organisms may respond through plasticity, evolution, or the evolution of plasticity. In this dissertation, I evaluate the role of plastic and evolved responses in the eastern oyster, Crassostrea virginica, to environmental variation in the northern Gulf of Mexico. I use comparative transcriptomics, physiology, and morphology to examine the relative contribution of plastic and evolved responses for oysters exposed to low salinity and outplant sites …

Sodium Mediates Developmentally Plastic Responses In Plants And Herbivores, Luis Santiago-Rosario

LSU Doctoral Dissertations

Sodium plays a crucial role in organismal performance, trophic-level interactions, and eco-evolutionary dynamics. For plants, sodium impacts osmoregulation, growth, and water uptake. For animals, sodium is essential influencing osmoregulatory processes, muscle and neural development, and blood regulation. My dissertation aims to disentangle why sodium mismatch affects resource-consumer interactions and its influence on morphological and behavioral plasticity. First, I identified how sodium impacts plant performance and sodium accumulation strategies. I initially focused my research on understanding how increasing substrate sodium affects plant growth and tissue sodium accumulation strategies in controlled settings using a systematic review approach. I found that saltier plants …

Singing Strategies Are Linked To Perch Use On Foraging Territories In Heart-Nosed Bats, Grace C. Smarsh, Ashley M. Long, Michael Smotherman

Faculty Publications

Acoustic communication allows animals to coordinate and optimize resource utilization in space. Cardioderma cor, the heart-nosed bat, is one of the few species of bats known to sing during nighttime foraging. Previous research found that heart-nosed bats react aggressively to song playback, supporting the territorial defense hypothesis of singing in this species. We further investigated the territorial defense hypothesis from an ecological standpoint, which predicts that singing should be associated with exclusive areas containing a resource, by tracking 14 individuals nightly during the dry seasons in Tanzania. We quantified the singing behavior of individuals at all perches used throughout the …

On The Need For New Measures Of Phylogenomic Support, Robert C. Thomson, Jeremy M. Brown

Faculty Publications

The scale of data sets used to infer phylogenies has grown dramatically in the last decades, providing researchers with an enormous amount of information with which to draw inferences about evolutionary history. However, standard approaches to assessing confidence in those inferences (e.g., nonparametric bootstrap proportions [BP] and Bayesian posterior probabilities [PPs]) are still deeply influenced by statistical procedures and frameworks that were developed when information was much more limited. These approaches largely quantify uncertainty caused by limited amounts of data, which is often vanishingly small with modern, genome-scale sequence data sets. As a consequence, today's phylogenomic studies routinely report near-complete …

Effects Of Freshwater Input On Nutrient Loading, Toxic Cyanobacteria Bloom Development And Cyanotoxin Production In Lake Pontchartrain Estuary, Louisiana, Callie L. Snow

LSU Master's Theses

Estuaries in the northern Gulf of Mexico (GoM) are undergoing profound alterations due to changes in climate and implementation of coastal restoration activities and these may lead to the increasing frequency of harmful algal blooms (HABs). The introduction of large volumes of nutrient-rich, fresh Mississippi River water into nutrient-poor Lake Pontchartrain Estuary is known to substantially change the chemistry and ecology of the estuary, and warm temperatures paired with the persistent nutrient loading into the estuary supports the proliferation of potentially toxic cyanobacteria blooms (CyanoHABs). Throughout 2019, a long-term opening of the Bonnet Carré Spillway (BCS), initially from February to …

Brood Abundance And Invertebrate Availability In Crop-Dominated Landscapes In The Prairie Pothole Region, Catrina V. Terry

LSU Master's Theses

The Prairie Pothole Region (PPR) is the most important region for ducks in North America, producing over half the ducks on the continent, and it is a priority landscape for wetland and grassland conservation. Agricultural expansion has changed the PPR, and the majority of grasslands and potholes have been converted into row-crops. The loss of nesting habitat has directly caused nest success to decline. Most of the remaining wetlands are surrounded by row-crops, and are considered lower quality because they receive runoff of sediment and chemicals, which may decrease primary forage for young ducklings as well as inhibit wetland vegetation. …

Genetic Structuring And Community Assembly In Neotropical Birds, Oscar Johnson

LSU Doctoral Dissertations

The factors that influence how species form is of fundamental interest to biology. Under the framework of the speciation cycle, the process begins by population subdivision creating structured populations that then diverge until two new species form. Following speciation, however, continued divergence is necessary for these new species to be able to coexist without adverse interactions, known as the transition to secondary sympatry. At this point the speciation cycle is complete and the process can begin anew. Many of the factors influencing these processes remain poorly understood. Here, I explore the factors that influence speciation and community assembly in Neotropical …

Historical Dna Solves An Evolutionary Mystery And Explains The Origin Of A Novel Phenotype In The New World Quails, Jessie Frances Salter

LSU Doctoral Dissertations

Observations of phenotypic diversity among closely-related organisms, especially those preserved as museum specimens, have driven the fields of systematics, taxonomy, and evolutionary biology for hundreds of years. In this dissertation, I used genomic data from modern and historical specimens to investigate the evolutionary processes that have generated phenotypic and genetic diversity in a highly polytypic group of birds, the New World quails (Odontophoridae), with a focus on the most phenotypically diverse member of this family: Northern Bobwhites (Colinus virginianus). To facilitate this work, I began by generating a highly contiguous reference genome assembly for Northern Bobwhites, which is …

Blue Carbon In South Florida's Mangroves: The Role Of Large Roots And Necromass, Zoë I. Shribman

LSU Master's Theses

Blue carbon sequestration and storage in mangroves largely result from belowground biomass allocation in response to flooded anaerobic soil conditions and nutrient availability. Biomass allocation to belowground roots is a major driver of mangrove soil formation and organic matter accumulation leading to blue carbon storage potential. Belowground biomass sampling in mangroves is labor intensive, limiting data availability on biomass stocks, particularly for large roots (>20 mm diameter) and necromass (dead roots). The mangrove nutrient model (NUMAN) uses mostly literature values to parameterize a soil cohort approach to simulate depth distribution of root mass and organic carbon concentration. We evaluated …

Population Structure In Two Imperiled Sparrows With Differing Vagility, Amie Elizabeth Settlecowski

LSU Doctoral Dissertations

Characterizing population structure and genetic differentiation can inform the management of imperiled species and the relative influences of ecological and evolutionary factors on species evolution. One trait that is expected to influence the amount of population structure a species exhibits is vagility, or the ability to move across the landscape. Species with higher vagility may be more likely to disperse, potentially facilitating gene flow among populations and limiting population structure. My dissertation focuses on characterizing population structure in 2 imperiled sparrows that are both largely nonmigratory with broad distributions in eastern North America: Seaside Sparrow (Ammospiza maritima) and Bachman’s Sparrow …

Phragmites Australis Dieback In The Mississippi River Delta: Chemical Profiles Of Soil Types And Restoration Potential, Herie Lee

LSU Master's Theses

Since 2016, there has been widespread dieback of P. australis in the Lower Mississippi River Delta (hereafter referred to as Lower MRD, which is defined as the Birds Foot Delta) with relatively little to no signs of recovery. The cause of the current dieback is not fully understood. This thesis explores P. australis with emphasis on chemical profile characterization of different soil types and its effects on plant growth and the potential for restoration in the Lower MRD.

In chapter 2, I characterized the chemical profiles of soils collected from healthy and dieback stands of Phragmites, and from newly …