Life Sciences Commons^™

Bryophytes Of Goochland County, Virginia, Mikayla Quinn

Honors Theses

Bryophytes are non-vascular land plants that include mosses, liverworts, and hornworts. Although easier to overlook because of their smaller size, bryophytes are a fundamental part of the ecosystem. As such, maintaining record of their biodiversity is important. Yet, records of bryophyte species in Goochland County, VA were low compared to more thoroughly documented counties such as Prince Edward County. This study expands the documentation of bryophyte flora and presents a checklist of bryophyte species found Virginia’s Goochland County from 2020-2023. Fieldwork conducted at public and privately-owned properties throughout the county between January 2020 and March 2023 yielded 702 specimens that …

Wetlands In Our Backyard: A Review Of Wetland Types In Virginia State Parks, Kirsten Bauer, Benjamin K. Campbell

Virginia Journal of Science

Wetlands constitute a significant component of Virginia’s natural resources and heritage. Though historically they have been discounted—and often denigrated—the exceptional value of wetlands is currently growing in recognition and appreciation. In addition to the value provided by extracted resources and ecological regulation, wetlands also offer people the opportunity to enrich themselves through cultural, educational, and recreational pursuits. The state parks of Virginia provide access to a variety of ecosystems, including a wide array of wetland types. In this review, we document the diversity of wetlands in Virginia State Parks through a typology that groups wetland systems into the three principal …

Enhancing Existing Isolated Underpasses With Fencing Reduces Wildlife Crashes And Connects Habitat, Bridget M. Donaldson, Kaitlyn E. M. Elliott

Human–Wildlife Interactions

The impact of wildlife–vehicle collisions on drivers and wildlife populations has been gaining attention in the United States. Given the established success of wildlife crossings with fencing in reducing wildlife crashes and connecting habitat, information is needed on cost-effective means of implementation for departments of transportation. When wildlife crossings are constructed, they are often built into new road projects as a series of 2 or more underpasses and/or overpass structures connected by exclusionary fencing. Given limited transportation budgets and the prevalence of maintenance activities more so than new construction in many states, enhancing existing underpasses on previously constructed roads has …

Habitat Utilization And Impact Of Flooding On James Spinymussel (Parvaspina Collina) Populations In Virginia Streams, Christine A. Verdream

Masters Theses, 2020-current

The James spinymussel (Parvaspina collina) is Critically Endangered and endemic to Virginia’s James River basin. P. collina was listed as Endangered in 1988 and more than 90% of the species has been lost over the last 30 years (USFWS 1990). Despite the development of a recovery plan in 1990, there has not been a comprehensive reassessment of P. collina in over 30 years. This study explored the relationship between flooding and P. collina population dynamics in a flood prone stream and further explained habitat occupancy. Study sites included Swift Run and Little Oregon Creek, both of which still …

Modeling Species Distribution And Habitat Suitability Of American Ginseng (Panax Quinquefolius) In Virginia, Jacob D. J. Peters

Masters Theses, 2020-current

American ginseng (Panax quinquefolius) is a well-known and sought-after medicinal plant native to North America that is facing increased threat of extinction due to overharvesting, herbivory, and habitat loss. Species distribution and habitat suitability models may be valuable to landowners interested in sustainable harvest or to institutions interested in the conservation and restoration of the species. With unequal sampling efforts across a region of interest, it is likely that some locations with appropriate habitat may be misrepresented in model predictions. This study refined a state-derived species distribution model for ginseng through increased sampling effort across the Cumberland Plateau …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2019 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the twenty-second year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2019, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on two fishery-independent monitoring programs using anchor gillnets in the Rappahannock River (year 2) and the Chickahominy River (year 5; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring …

The Diversity And Distribution Of Spiders (Arachnida: Araneae) Along An Outdoor – Indoor Habitat Gradient: Preliminary Findings From Piedmont Virginia, William Kish, Sujan Henkanaththegedara

Virginia Journal of Science

Although the United States supports a considerable diversity of spiders, some aspects of spider habitat use and niche specialization are poorly documented. Specifically, little attention has been given to explore how urban development affects the diversity and abundance of arthropods. We sampled spiders along an outdoor – indoor habitat gradient at Longwood University to understand the impact of urbanization on species diversity and abundance. We found 50 taxa of spiders belonging to 43 genera and 16 families. Overall, the most abundant spider family across three sampling sites was Araneidae (orb-weavers; 18.2%) followed by Lycosidae (wolf spiders; 14.8%), Salticidae (jumping spiders; …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2018 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the twenty-first year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2018, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on two fishery-independent monitoring programs using anchor gillnets in the Rappahannock River (year 1) and the Chickahominy River (year 4; a major tributary of the James River), to determine relative abundance and stock structure for the adult spawning run of river herring …

Microhabitat Comparison Of Percina Roanoka (Roanoke Darter) And Percina Nevisense (Chainback Darter) In The Roanoke River, Dakota R. Spruill, Steven L. Powers

Virginia Journal of Science

Snorkel observations of Percina roanoka and P. nevisense in the Roanoke River during summer months were followed by measuring current velocity, water depth, and substrate diameter at points of occupation. A total of 89 observations of P. roanoka and 81 observations of P. nevisense were compared using two-sample T-tests. Percina roanoka inhabited faster, shallower water than P. nevisense with the former found in a mean flow of 0.318 m/s and depth of 31.53 cm and the latter in a mean flow of 0.17 m/s and depth of 55.6 cm. Mean diameter of substrate at points of occupation did not differ …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2017 Annual Report, Eric J. Hilton, Rob Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the twentieth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2017, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on two fishery-independent monitoring programs, one using staked gillnets in the Rappahannock River (year 2) and the other using anchor gillnets in the Chickahominy River (year 3; a major tributary of the James River),to determine relative abundance and stock structure for the …

Compositional Changes In Two Small Mammal Communities During Succession In Southeastern Virginia, Robert K. Rose, Robyn M. Nadolny, Jay Kiser, Stephen E. Rice, Heather Green Salamone, Jana Eggleston, Holly D. Gaff

Virginia Journal of Science

Changes in the composition of two small mammal communities were studied during 8 and 9 years of ecological succession in southern Chesapeake. Virginia. Using monthly live-trapping on grids of similar size and history since their abandonment as agricultural fields, we learned that house mice were early colonists on one grid but not the other. Two species of herbivorous rodent and the granivorous eastern harvest mouse were numerically dominant on both grids across the study. Some species disappeared early on one grid but persisted to the end at the other. The two arboreal small mammals, golden and white-footed mice, were most …

Habitat Use By Bats On The Upper Coastal Plain Of Virginia, A. Scott Bellows, Joseph C. Mitchell

Virginia Journal of Science

We monitored bat activity on the upper Coastal Plain of Virginia using mist nets and acoustic detection (ANABAT) during April-October 2000 and April-August 2001. We classified forty sites into three forest-cover classes (pine forest, mixed pine, and hardwood forest) and three landscape-feature classes (permanent water, riparian corridor, and upland). We captured 406 bats (8 species) in mist nets; red bats (Lasiurus borealis; n = 281), big brown bats (Eptesicus fuscus; n = 47), and eastern pipistrelles (Pipistrellus subflavus; n = 36) were the most commonly captured species. We captured fewer than 30 individuals of …

Monitoring The Abundance Of American Shad And River Herring In Virginia's Rivers - 2016 Annual Report, Eric J. Hilton, Robert Latour, Patrick E. Mcgrath, Brian Watkins, Ashleigh Magee

Reports

This report describes the results of the nineteenth year of a continuing study to estimate the relative abundance and assess the status of American shad (Alosa sapidissima) stocks in Virginia by monitoring the spawning runs in the James, York and Rappahannock rivers in spring 2016, evaluating hatchery programs, and contributing to coast-wide assessments (ASMFC 2007). We also report on a new fishery-independent monitoring program using staked gillnets to determine relative abundance and stock structure for the adult spawning run of river herring (A. pseudoharengus, and A. aestivalis) in the Rappahannock River. Data are also reported from two separate fishery-independent monitoring …

Population Dynamics Of The Cotton Rat In Southeastern Virginia, Robert K. Rose, Heather Green Salamone

Virginia Journal of Science

Abstract

We used monthly live trapping for 2.5 years to evaluate the life-history features of the most common small mammal, Sigmodon hispidus (hispid cotton rat), in an old field at its northern limit of distribution on the Atlantic coast. Peak densities, achieved in late autumn or early winter, were among the highest recorded for the species and were more typical of marginal populations rather than of central ones. Unlike some other marginal populations, hispid cotton rats in eastern Virginia did not lose significant body mass over the winter (when few juveniles were present) and survival in winter was not significantly …

2016 Aerial Imagery Acquired To Monitor The Distribution And Abundance Of Submerged Aquatic Vegetation In Chesapeake Bay And Coastal Bays, Robert J. Orth, David J. Wilcox, Jennifer R. Whiting, Anna K. Kenne, Erica R. Smith, L. Nagey

Data

Multispectral aerial imagery acquired in 2016 to monitor the distribution and abundance of submerged aquatic vegetation in Chesapeake Bay and coastal bays.

A Comparative Analysis Of Geometric Morphometrics Across Two Pseudemys Turtle Species In East Central Virginia, Kristin C. Dillard

Theses and Dissertations

The phylogeny of the turtle genus Pseudemys is poorly understood. In Virginia, many turtles have been found with indicator traits of both eastern river cooters (Pseudemys concinna concinna) and northern red bellied cooters (Pseudemys rubriventris). This study explores morphological evidence for hybridization between the two species across three riverine sites in east central Virginia.

Museum voucher groups for each species were analyzed for relative shell height and plastron length. The shape of the plastral scutes and upper jaw were analyzed using landmark-based morphometric software. These metrics were compared with measurements taken from 188 field-caught Pseudemys specimens. …

An Analysis Of Particulate Matter In Central Virginia, Elizabeth Garrett, Arif Sikder

Rice Rivers Center Research Symposium

Virginia is consistently rated as a state with high rates of asthma (Asthma and Allergy Foundation 2014). Although this respiratory disease has many causes, certain air pollutants can be a trigger. The EPA currently identifies, monitors, and regulates seven types of air pollutants. One of these pollutants, particulate matter, can occur both naturally and culturally. The primary anthropogenic cause of particulate matter is fly ash, which is formed during fossil fuel combustion. Different technology installed in the power plant can capture some of the fly ash but these methods are not entirely effective.

This study focused on estimating the ratio …

Evaluating Recruitment Of American Eel, Anguilla Rostrata, In The Potomac River (Spring 2016), Troy D. Tuckey, Mary C. Fabrizio

Reports

American Eel (Anguilla rostrata) is a valuable commercial species along the Atlantic coast of North America from New Brunswick to Florida. Landings from Chesapeake Bay typically represent 60% of the annual United States commercial harvest (ASMFC 2012). American Eel is also important to the recreational fishery as it is often used live as bait for Striped Bass (Morone saxatilis) and Cobia (Rachycentron canadum). In 2012, Chesapeake Bay commercial landings of American Eel (771,536 lbs) were 72% of the U.S. landings (personal communication from the National Marine Fisheries Service, Fisheries Statistics Division). Since the 1980s, harvest along the U.S. Atlantic Coast …

Virginia’S Amphibians: Status, Threats And Conservation, Jennifer Sevin, John D. Kleopfer

Virginia Journal of Science

Virginia’s diverse environments support 84 amphibian species (anurans and caudates), making it the third highest state in terms of species richness. However, the Commonwealth matches the global trend in declining amphibian populations with over one-third of its amphibian species in conservation need. The Species of Greatest Conservation Need included in the most recent Virginia Wildlife Action Plan cut across amphibian families and ecoregions. It is challenging to ascertain the exact cause of most of the population declines. In one degree or another, all of the global threats to amphibians exist within Virginia’s borders. While an active research program on amphibians …

Breeding Birds Of Virginia, Bryan D. Watts

Virginia Journal of Science

Virginia supports a diverse community of breeding birds that has been the focus of investigation for more than 400 years. The avifauna reflects the latitudinal position of the state and the fact that the border extends from the Atlantic Ocean to the Appalachian Mountains. A total of 224 species have been recorded breeding in Virginia, 214 of which are extant. Twenty species have colonized the state since 1900 including 14 since 1950. Of all extant species, 102 (48%) are considered common at least somewhere in the state and 64 (30%) are rare to very rare. Diversity varies by physiographic region …

Virginia’S Land Mammals: Past And Present, With Some Thoughts About Their Possible Future, John F. Pagels, Nancy D. Moncrief

Virginia Journal of Science

Mammals encountered today in Virginia’s forests and fields include native and nonnative species, feral populations, and free-ranging pets. We examine factors that have influenced Virginia’s terrestrial mammal fauna since the arrival of European colonists in the 1600s and some of the factors that are shaping the fauna today. We look in depth at changes since Handley and Patton’s (1947) first complete monograph on Virginia mammals and augment Linzey’s (1998) book, The Mammals of Virginia. We include current nomenclature, baseline information, and references to comprehensive literature. We discuss some of the current and developing anthropogenic factors that have impacted, or that …

Blue Carbon In Coastal Freshwater/Brackish Marshes On The Barrier Islands Of Virginia: Belowground Carbon Dynamics, Nathan M. Sedghi

Biological Sciences Theses & Dissertations

Some coastal ecosystems sequester substantially more carbon (blue carbon) than land locked systems due to high net primary production and deposition associated with oceanic influences. Most blue carbon research has focused on mangroves, seagrass beds, and salt marshes. Studies on blue carbon potential of coastal freshwater marshes are less common. Barrier islands frequently flood, with seawater reaching interior ecosystems. I examined brackish/freshwater marshes on Virginia barrier islands for possible roles as blue carbon systems. I studied four interior marshes on Hog Island, which varied in proximity to a direct overwash path and protection by a trail berm that divides northern …

Blue Carbon In Freshwater / Brackish Marshes On The Barrier Islands Of Virginia Aboveground Net Primary Productivity And Carbon Pools, Emily Caitlin Adams

Biological Sciences Theses & Dissertations

"Blue carbon" is a relatively new concept describing carbon distributed tidally and sequestered via net production within coastal ecosystems, including seagrass beds, mangrove forests, and salt-water marshes. These systems sequester carbon at least 10 times faster than terrestrial systems. Fresh to brackish wetlands that receive irregular tidal influence due to overwash and storm events have not been typically studied as blue carbon systems. My objective was to quantify carbon pools within four interdunal fresh to brackish marshes on Hog Island, Virginia to determine their blue carbon potential. Marshes 1 and 2 were farthest from the ocean, below and above a …

Life-History Aspects Of Moxostoma Cervinum (Blacktip Jumprock) In The Roanoke River, Virginia, Dezarai A. Thompson, John S. Bentley, Steven L. Powers

Virginia Journal of Science

Life-history aspects of Moxostoma cervinum(Blacktip Jumprock) were identified using specimens from recent collections and the Roanoke College Ichthyological Collection. The largest specimen examined was a female 161.27 mm SL and 66 months of age. Spawning appears to occur in May, with a mean of 2477.6 oocytes (SD = 2825.3) up to 1.54 mm diameter in gravid females. Sexual maturity appears to occur by 1-2 years of age in males and 2-3 years of age in females. Male to female ratio was not significantly different from 1:1. Chironomidae composed the bulk of the diet; while detritus, Trichoptera, Ephemeroptera, and Acari …

Agricultural/Forestal Districts: Surveying Afd Landowners In Augusta County And The City Of Staunton To Determine Areas For Program Improvement And Program Promotion Strategies, Martin Driver

Masters Theses, 2010-2019

Agricultural/Forestal Districts (AFDs) are rural conservation zones reserved for the production of agricultural products and function to protect agricultural and forestal lands as important natural resources. These districts are formed voluntarily by Virginia landowners and provide a number of important benefits to the landowners and surrounding communities. From a stewardship and administration standpoint, it would benefit both landowners and administrators to determine areas needing improvement within the AFD program. Also, it would be beneficial to these same parties to determine optimal methods for promoting the program to landowners who are not currently AFD members. The evaluation and understanding of these …

Carrion Beetle (Coleoptera: Silphidae) Carcass Selection: Effects Of Carcass Mass And Site Fidelity, Jonathan M. Schmude

Biological Sciences Theses & Dissertations

This study investigated reproductive behaviours of the carrion beetles (Coleoptera: Silphidae) of southeastern Virginia. Carrion beetles have been known to have ranges of carcass masses used for reproductive behaviors. In this study, pitfall traps were baited with 25g, 50g, or 75g of a cat food/mackerel mixture and left to decay and attract beetles for one week to investigate if any Silphidae species prefer a single mass over another. This study investigated the carcass bait mass that is used on the subfamily and species level, and how the beetle mass plays a role in preference. The study also investigated the effect …

Thresholds Of Change In Decomposition Rate Along A Dune/Swale Transect On A Virginia Barrier Island, Dominic J. Graziani

Biological Sciences Theses & Dissertations

Aboveground and belowground decomposition rates were determined along a barrier island dune/swale transect located on the Virginia Coast Reserve-Long Term Ecological Research Site using litterbags and wooden dowels. The objective was to determine the influence of fine scale changes in the environment on decomposition to identify any potential thresholds affecting decomposition rate. Wax myrtle (Morella cerifera L. Small) leaves and dowels of southern yellow pine wood were used as standard substrates to evaluate environmental influences on decay. Aboveground (F=6.494, p < 0.0001) and belowground (F=5.705, p < 0.0001) decay rates (yr^-1) showed significant variation among litterbag/dowel locations. Aboveground decay rates (yr^-1) ranged from 0.339 (Upper Dune station) …

Life History Of Stranded Bottlenose Dolphins (Tursiops Truncatus) In Virginia, Margaret Cook Lynott

Biological Sciences Theses & Dissertations

Little is known about the life history and overall ecology of bottlenose dolphins that strand in Virginia. In this study, I examined archived life history samples and stranding data from bottlenose dolphins found in Virginia waters to (1) develop growth curves based on ages from sectioned teeth, (2) document characteristics of male and female reproductive organs, and (3) define the relationship between age/length and presence of neonatal characteristics during the first year of life. The Gompertz growth model provided the best fit of growth data for stranded T. truncatus in Virginia. Length at birth and asymptotic length for males were …

Effects Of The Parasitic Dinoflagellate Hematodinium Sp. On Blue Crab (Callinectes Sapidus) Activity Predation And Habitat Selection, John M. Tiggelaar Ii

Biological Sciences Theses & Dissertations

The blue crab Callinectes sapidus occurs along the Atlantic and Gulf coasts of the United States, and in high salinity regions, they are subject to lethal infection by the parasitic dinoflagellate Hematodinium. In Virginia's seaside estuaries, the prevalence of Hematodinium infection of C. sapidus can sometimes exceed 50%, threatening the commercial fishery for this species. Indeed, other commercially important crustacean fisheries have approached collapse due to Hematodinium infections. Most studies of this host-parasite interaction have focused on epidemiology, host-pathogen dynamics, and pathogen transmission, and little is known about the impact of the parasite on host behavior and population dynamics. …

The Ecology Of The Timber Rattlesnake (Crotalus Horridus) In Southeastern Virginia, Scott M. Goetz

Biological Sciences Theses & Dissertations

Few studies have examined the relationship between forest canopy structure and the ecology of the timber rattlesnake (Crotalus horridus). I used radiotelemetry to compare the movements, activity range sizes and behaviors of timber rattlesnakes before and after a large-scale natural disturbance that opened a previously closed canopy. The disturbance was Hurricane Isabel which made landfall in northeast North Carolina and southeastern Virginia in 2003. Isabel created gaps in the canopy through tree blowdown, resulting in a 16.6% opening in the forest canopy at my study site, in southeastern Virginia. I compared six years of female tracking data from …