Ecology and Evolutionary Biology Commons^™

Incorporating Demographic Structure And Variable Interaction Types Into Community Assembly Models, Akhil Reddy Alasandagutti, Nayan Chawla

Honors Theses

Theoretical studies of ecological food webs have allowed ecologists to remove the constraints of specific location and timescales from their study of ecological communities; food webs are generally complex and thus empirical study is difficult. Further, this theoretical approach allows ecologists to compare ecological processes and outcomes across any possible food web structures. However, these simulated communities are only as useful as the model from which they were constructed. Modifying existing considerations in these models, and generating new ones, are the jobs of theoretical ecologists that seek to achieve the shared goal of a majority of simulations: representation of real …

A Baseline Documentation Report For The Delta Wind Birds Sky Lake Nature Reserve, James Dubberly

Honors Theses

The purpose of this baseline documentation is to conduct a report on our subject property and discuss the findings. A conservation easement is established by upholding a certain standard of a property’s current condition which makes a baseline documentation necessary for an easement to be enacted. Baseline documentation reports are used as a resource to monitor and enforce the legal agreements of the conservation easement. The subject property is currently owned by the Delta Wind Birds organization. In our scenario, this documentation report will serve to aid in the conversion of our subject property into a conservation easement in which …

Density Dependent Growth Of Pseudomonas Fluorescens In The Presence And Absence Of C. Elegans Predation In Liquid Media, Jack Landmann

Honors Theses

The purpose of this study was to understand the predator-prey relationship between C. elegans worms and P. fluorescens bacteria in liquid media. We were aiming to create a predation model of the relationship between these two species.

This study was performed through three experiments. Using 96-well plates, we were able to measure the change in optical density (OD) of these wells and calculate the growth rate. This growth rate was then graphed and analyzed. The first experiment contained P. fluorescens and KB liquid media, this study demonstrated that the bacterial population has a carrying capacity. We were also able to …

Warming Stimulates Sporulation Rates And Alters Community Structure Of Litter-Associated Fungi In Streamside Channel Experiment, Kaitlin D. Beasley-Polko

Honors Theses

Fungi, such as aquatic hyphomycetes, are important decomposers of plant litter in temperate forested headwater streams providing energy and nutrients for the higher trophic levels in these ecosystems. According to current climate change predictions, stream water temperatures are expected to rise significantly in the near future. This project addressed the effects of temperature on sporulation rates and community structure of aquatic hyphomycetes on substrates of different carbon quality (maple and rhododendron leaf litter and wood veneers). The experiment was conducted in streamside channels fed with stream water (ambient, +2°C and +4°C) and set up to mimic small streams. We found …

Genetic Diversity & Connectivity Of Chasmanthium Latifolium (Poaceae) In Pennsylvania & The Effect On Conservation Status Of A Rare Species, Jonathan D. Hayes

Honors Theses

Chasmanthium latifolium (Michx.) Yates (Poaceae) is a loosely colonial, rhizomatous, perennial grass species that lives in riparian habitats, making it fittingly referred to as river oats. Native to the southern Midwest and the eastern half of the United States, C. latifolium reaches the northeastern edge of its range in Pennsylvania. Within Pennsylvania, eleven extant C. latifolium populations are found along four waterways: the Monongahela River, the Susquehanna River, and two tributaries to the Susquehanna River. This limited state distribution exhibits an east-west disjunct distribution, where western populations are largely separated from eastern populations with one centrally located population. Between the …

Impact Of The North American Monsoon On Molt Migrant Passerines, Liuqingqing Yang

Honors Theses

Breeding, molt, and migration place considerable yearly demands on migrating passerines in North America. Due to conflicts in energy allocation, many species have evolved migration strategies that prevent temporal overlap in these processes. However, there is recent evidence that some passerines which breed in western North America migrate to intermediate stopover sites to carry out molt, conflating molt and migration. Factors influencing the evolution of such a strategy are believed to include both aridity on breeding grounds and dependable flushes of late-summer productivity in the southwestern United States and northwestern Mexico. This productivity occurs due to the brisk rainfall of …

Morphological Variance In Mouthparts And Foraging Behavior In Bumblebees, Ye Jin Lee

Honors Theses

Bumblebees (Hymenoptera: Apidae: Bombus) show an incredible degree of size variation within and between species. Individuals from the same hive may vary up to 10-fold in mass. This variation allows individuals to specialize in foraging on different flowers suited to their morphology. However, as different species have different foraging behaviors, their variation in mouthparts and scaling of mouthparts to body size may have been under different kinds of stabilizing selection as they adapted to collect nectar from flowering plants over evolutionary time. Here, we examined the scaling relationships between body size and mouthpart structures, and the variation in mouthpart shape …

Contrasting Patterns Of Nutrient Limitation In The Littoral And Pelagic Zones Of Mesotrophic Maine Lakes, Grace C. Neumiller

Honors Theses

Intense nutrient loading of nitrogen (N) and phosphorus (P) causes sudden regime shifts in freshwater ecosystems from clearwater to turbid conditions with frequent cyanobacterial blooms. Characterization of nutrient limitation patterns of primary productivity in these ecosystems is necessary for effective management of algal blooms. However, much of this research has focused on pelagic habitats. The influence of lake habitat (i.e. benthic littoral versus pelagic zones) on nutrient limitation of primary production in mesotrophic lakes is largely unknown, particularly in contrast to research on pelagic nutrient limitation in eutrophic systems. Using paired nutrient diffusing substrata and mesocosm experiments, we measured chlorophyll- …

A Foray Into The Interval Timing Capabilities Of Tufted Capuchin Monkeys (Cebus [Sapajus] Apella), Gryff Griffin

Honors Theses

Time is a critical part of life and timing on the range from milliseconds to minutes has proven to be critical for several behaviors such as foraging and movement. While the exact neurological structures of interval timing are currently undefined, several studies have been completed comparing the interval timing capabilities of humans and nonhuman primates. However, these studies have unanimously utilized members of Macaca, which limits the abilities for researchers to make apt comparisons between humans and all nonhuman primates. This study sought to investigate whether tufted capuchins (Cebus [Sapajus] apella) have the capability to measure time …

Blenny Territoriality At Oyster Landing, North Inlet Estuary, South Carolina: Seasonal Patterns And Ecological Factors, Sydney Davis, Juliana Harding

Honors Theses

Temperate oyster reef blennies use oyster shells that are still articulated as habitat year round. During the breeding season when water temperatures are > 18-20°C, many species of blenny males use the oyster valves as nesting sites. Male blennies exhibit territorial behavior when guarding their nesting sites and can interact differently with conspecific and transient species. Striped blenny (Chasmodes bosquianus) and freckled blenny (Hypsoblennius ionthas) behavior was described from April 2020 to August 2020 at Oyster Landing, North Inlet estuary, South Carolina to quantify typical blenny behavior, general presence or absence of residents, and potential environmental parameters …

Infaunal Bivalve Density And Richness In North Inlet Estuary, South Carolina: Seasonal Patterns And Ecological Factors, Valerie M. Knowles, Juliana Harding

Honors Theses

Estuarine bivalves recruit to benthic habitats after the larvae are in the planktonic stage. The observed infaunal bivalve density relates to larval supply from adult reproduction during warmer months as well as larval and juvenile mortality post-recruitment. The purpose of this research was to examine annual and seasonal patterns of infaunal bivalve density and richness in the context of habitat water temperature and salinity. Cores were collected biweekly from Bly Creek in North Inlet estuary between January 2019 and February 2020. Temperatures ranged from 9-30 ºC and salinity ranged from ~17-36 psu. Bivalves were sieved out of the cores, counted, …

Population Genetics Of A Recent Range Expansion By The Southern Pine Beetle, Dendroctonus Frontalis, Into The Northeastern United States, Megan Stubbs

Honors Theses

Population genetics as a field of study aims to determine the genetic variation among individuals in a population, and differences among populations. Certain population genetic analyses can provide such information and be used to better understand the biological aspects to a species’ expansion beyond its native range. The southern pine beetle (SPB), Dendroctonus frontalis, has become an invasive pest to pine forests in northeastern United States with its recent range expansion. Nine microsatellite loci were first developed and then used in analyses. To determine what the genetic variation is among individuals in SPB populations across its entire range, including …

Behavioral Ecology Of Territorial Aggression In Uca Pugilator And Uca Pugnax, Abbey N. Thomas

Honors Theses

The nature of animal aggression has long been a research interest in many different scientific fields. Resources, including food, shelter, and mates are all common assets for which animals compete. Two species of fiddler crabs, the Atlantic Sand Fiddler Crab (Uca pugilator) and the Atlantic Marsh Fiddler Crab (U. pugnax) were studied in regards to their aggression shown when competing for shelter. One crab was placed in a contained shelter for two days, and then a second of the same species was introduced. Aggressive interactions were scored and compared with claw and carapace size to ascertain …

Is Anyone Home? Year Round Site Fidelity Vs. Temporal Territories In Estuarine Blennies, Nicholas Govostes

Honors Theses

Temperate oyster reef blennies use articulated oyster shells as nest sites in warmer months during breeding season but little is known about their site fidelity during non-breeding season. Unlike coral reef blennies that occupy territories year-round, rocky intertidal temperate blenny species display temporal territories and seasonally migrate into breeding shelters. Striped blenny (Chasmodes bosquianus) shelter use was described from November 2019 through March 2020 at Oyster Landing, North Inlet estuary, SC to quantify the proportion of daylight hours when fish were in residence and describe potential relationships between shelter occupancy and neighboring fishes. Replicate PVC shelters were monitored …

Development Of Methods To Track Oyster Movement Under Field Conditions In North Inlet Estuary, South Carolina, Alyssa M. Leclaire

Honors Theses

Eastern oyster (Crassostrea virginica) reefs provide important habitat structure and ecosystem services in saltmarsh tidal creek estuaries. Reef persistence depends on growth of resident individuals and regular recruitment to maintain suitable shell substrate. Boat wakes potentially physically displace oyster clumps. The objective of this research was to develop methods to track oyster clump position and biomass on two natural fringing oyster reefs in North Inlet estuary, South Carolina. Boat traffic (number of boats making wakes per day), oyster clump displacement (cm/d) over time, oyster biomass (g dry tissue), and condition index (biomass/g dry shell weight) were quantified from …

Patterns Of Genomic Introgression In Topminnow Hybrid Zones, Amanda F. Ray

Honors Theses

Hybridization and introgression are two important evolutionary mechanisms that can increase genetic diversity. Interesting introgression patterns can form when parental species have genes that confer some adaptive benefit to the organism. The Fundulus notatus species complex contains species with various identifying characterisics. Fundulus notatus, the blackstripe topminnow, and Fundulus olivaceus, the blackspotted topminnow, are closely related and occupy many of the same rivers in their preferred niches. These two species often hybridize and form hybrid zones where their niches overlap. We studied two hybrid zones located in the Tombigbee River and Spring River. Within each hybrid zone, we …

Identification Of Odorant Receptor Genes In The Antennal Transcriptome Of The Common Eastern Fireflies, Photinus Pyralis, Hanh Tran

Honors Theses

The insect odorant receptor, OR, gene family has been hypothesized to play a critical role in reproduction. Odorant receptor proteins, located on the olfactory sensory neuronal dendrites, detect odorant chemicals such as pheromones and then mediate key behaviors such as mate choice. Although olfaction is known to play a predominant role in sexual communication, there are still large numbers of olfactory genes that have not been studied in many insect species including fireflies. In this study, I investigated the sequencing data of one of the common eastern fireflies, Photinus pyralis (Coleoptera: Lampyridae). This firefly species is well known for their …

Predation Effects On Mid-Marsh Ribbed Mussel Mortality, Cluster Size, And Facilitation Of Cordgrass Growth, Colten Winter, Keith Walters

Honors Theses

Reciprocal facilitation between Geukensia demissa, ribbed mussels, and Sporobolus alterniflorus, cordgrass, has a positive effect on salt marsh ecosystems. Mussel clusters enhance cordgrass growth and drought resistance and cordgrass provides attachment and shade for mussel aggregations. Along with benefits for both mussels and cordgrass, the mutualism facilitates increased biodiversity and shoreline stabilization and enhances marsh ecosystem functions. Aspects of mussel patch configuration including cluster size, perimeter and connectivity modulate the reciprocal facilitation effects of cordgrass and mussels on marsh ecosystems. In a northern South Carolina marsh system, mussel patch configuration positively influenced cordgrass biomass. Predation affected mussel patch …

Density And Species Richness Of Macrofaunal Benthic Bivalves In North Inlet Estuary, South Carolina, Richard Hawley, Juliana Harding

Honors Theses

Marine benthic bivalves are consumed by higher trophic levels. Bivalve species richness and density depend on temperature, salinity, and location. Biweekly core samples were collected from Bly Creek from 12/2017 to 12/2018. Benthic macrofaunal bivalves were counted and identified to describe density and species richness. Bivalves were also photographed for species identification. Bivalves composed 0% to 17% of the total macrofauna. The maximum bivalve density (8,149 bivalves/m²) was recorded on December 23, 2018. The fewest bivalves were observed from December 2017 through March 2018. Eight bivalve species were recorded during 2018; at least one species was present year-round. …

Demersal Fish Use Of Printed Oyster Shells As Nesting Habitat In North Inlet Estuary, Sc, Annie Boyd, Juliana Harding

Honors Theses

Temperate estuarine blenny species establish subtidal territories and nesting sites. Four blenny species co-occur in North Inlet, SC including the striped blenny, Chasmodes bosquianus, crested blenny, Hypleurochilus geminatus, feather blenny, Hypsoblennius hentzi, and freckled blenny, Hypsoblennius ionthas. All four fishes use empty oyster (Crassostrea virginica) shells as nesting sites. Current 3D printer technology was used to create standard nest substrates to describe relationships between blenny habitat use and nest site dimensions. Replicate printed shells of 2 gape widths (5, 7 mm) for each of 2 shell cavity volumes (22 mL, 15mL, Oyster A and …

Age-Related Tick Infestation Patterns In Springtime Migratory Passerines, Matthew Dunning

Honors Theses

To test the hypothesis that younger migrants are more prone to arrive at stopover sites on the northern coast of the Gulf of Mexico with ticks than adult migrants, 2177 migratory passerines were screened for ticks at Gulf Coast sites in Texas and Louisiana. Fifty eight (2.7%) were infested with ticks with 28 (1.3%) being young birds and 30 (1.4%) being adult birds. The body condition of the birds was assessed to determine if tick infestation had negative consequences and if the severity of consequences varied between ages. I found no relationship of age with the prevalence of a tick …

Insects And The Evolution Of Developmental Pathways: Functional Analysis Of Genetic Sex Determination Mechanisms In Oncopeltus Fasciatus, Josefine Just

Honors Theses

Natural selection alters genetic pathways over evolutionary time. However, different pathways have been shown to maintain mutations at varying rates, leading to different levels of conservation across developmental pathways. Sex determination pathways, in particular, show vast diversity across animals despite the fundamental conservation of biological sex itself. Here, I investigated the sex determination pathway of the hemimetabolous insect, Oncopeltus fasciatus. The large milkweed bug, O. fasciatus, is part of the order Hemiptera, which provides a relevant outgroup study to other insects in which sex determination has been studied to date. I studied three sex determination genes, intersex, fruitless …

Tracking The Endangered Northern Black Racer, Coluber Constrictor Constrictor, In Maine To Determine Areas Of Conservation Importance, Josiah Johnson

Honors Theses

The Black Racer (Coluber constrictor) is a large-bodied snake species found across North America. One subspecies, the Northern Black Racer (C. constrictor constrictor) is listed as endangered in Maine because of its restricted range in York County. Racers have generally been found to prefer open habitats and ecotones, but the specific habitat preferences of racers in Maine is unknown, hindering efforts to preserve habitat for racer conservation. To address this knowledge gap, the Maine Department of Inland Fisheries and Wildlife (MDIFW) has an ongoing project tracking black racer movements in Sanford and Kennebunk, Maine, and I had the opportunity to …

African Savannah Elephant Group Size And Behavior In The Makgadikgadi Pans National Park, Botswana, Katherine S. King

Honors Theses

African savannah elephants (Loxodonta africana), the largest elephant species, influence the structure of the environment they inhabit. Elephants exhibit complex patterns of social behavior between individuals within a population. Many behavioral studies focus on interactions among individuals within a population rather than broader trends related to group size. My study seeks to understand how male African savannah elephant group size is influenced by seasonality, age, physical condition and distance to permanent water resources. I examined the interaction of these variables in two ways: (1) a literature review of elephant behavior and conservation, and (2) an analysis of male …

Use Of Co-Immunoprecipitations And 2d Gel Electrophoresis To Identify Protein-Protein Interactions Of Maturase K, Lauren Angello

Honors Theses

Maturase K (MatK) is the only group II intron encoded protein in the chloroplast of land plants. Maturases are prokaryotic enzymes that catalyze formation of the lariat structure needed for intron removal from precursor RNAs. The chloroplast maturase MatK, is a descendant of prokaryotic maturases, however, unlike its prokaryotic relatives, MatK is thought to catalyze excision of, not only its own intron, but also the introns of other group II introns in the plastome. Similar to the multiprotein and snRNA spliceosomal complex of the nucleus, it is postulated that MatK is not working alone to excise these introns but most …

Effect Of Reinforcement Selection On Mate Selection Rates Of Gambusia Affinis And Gambusia Holbrooki, Molly Stephens

Honors Theses

This study was conducted in order to investigate the effects that reinforcement selection has on non-hybridized and hybridized populations of two separate species of Gambusia (G. affinis and G. holbrooki). In order to examine if organisms from a population that had been previously exposed to hybridization would choose mates so as to not produce species hybrid offspring, 29 trials consisting of 9 different mate preference combinations and 87 individuals were recorded and analyzed. Once mate preference was determined for each female used in each trial, the effect that reproductive isolation had on reinforcement in hybrid zones was analyzed. The results …

Sibship Reconstruction For Inferring The Number Of Breeders Of Gulf Sturgeon In The Apalachicola River, Robbilyn Verges

Honors Theses

The Gulf sturgeon is an anadromous fish that inhabits the Gulf of Mexico and its neighboring river drainages. The species is currently listed as threatened due to habitat alterations and overfishing. In this study, we focused on the Apalachicola River in Florida, which has had several historic spawning locations of the sturgeon blocked by the Jim Woodruff Lock and Dam. Age-1 juvenile sturgeon from the year 2013 (n=31) and 2014 (n=131) were genotyped using fourteen microsatellite loci. Sibship reconstruction and parentage assignment was performed in order to determine the effective number of breeders (Nb) and the total number of spawning …

Genetic Estimates Of The Number Of Breeding Adults In Alligator Gar From The Choke Canyon Reservoir, Texas, E. Blayne Newsome

Honors Theses

Alligator gar were historically found across the coastal drainages of the Gulf of Mexico and up into the Mississippi River basin. However, their populations are experiencing decline in many portions of their range. Texas seems to have large populations of alligator gar, but state resource officers are seeking to better understand its biology so as to provide appropriate management recommendations to maintain the recreational fishery. In this study, I used genetic techniques to examine a cohort of 144 juvenile alligator gar collected in 2016 in the Choke Canyon Reservoir. By estimating the effective number of breeders and number of spawning …

Role Of Nest Site Microclimate And Food Availability In Chick Development And Reproductive Success In Black-Legged Kittiwakes (Rissa Tridactyla), Lindsay Mae Lacey

Honors Theses

Seabirds are marine top predators, and as such are often studied as bioindicators of climate shifts (Oswald and Arnold 2012). Though many studies have analyzed the effect of macroclimatic variation on marine prey species availability and thus seabirds, few have analyzed effects of microclimate - fine spatial patterns of climate (Mantua and Hare 2002; Hatch 2013; Kim and Monaghan 2005a). I tested the hypothesis that localized temperature and humidity at nest sites interact with food availability to alter black-legged kittiwake (Rissa tridactyla) nest site quality, chick body condition during growth and development, and reproductive parameters including Julian lay …

Salinity Tolerance Of Gambusia Affinis, Sarah Rubelowsky

Honors Theses

Developmental plasticity refers to changes during development as a result of environmental contributions. Salinity is a varying environmental condition in freshwater and estuarine habitats that can mediate developmental plasticity in Gambusia affinis, which can increase their tolerances as an invasive species. For my study, estuarine and freshwater populations of Gambusia affinis were sampled in March of 2017 using dip nets. Both populations were then brought back to the laboratory where pregnant females were acclimated to three different salinities (0‰, 15‰, 25‰) until they gave birth. I predicted that the estuarine population of Gambusia affinis would have a greater salinity tolerance …