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Camera Trap Survey Suggests Forestry And Prescribed Burns Attract Wildlife, But May Not Enhance Diversity, Melissa S. Vilgats, Ryan Ott, Stephanie S. Coster

Virginia Journal of Science

This study explored whether habitat management techniques such as forest thinning and burning promoted biodiversity. Fifteen camera trap stations were established at Fort A.P. Hill in Bowling Green, VA across forest stands with low, medium, and high basal area. Camera traps were deployed for a total of 532 trap nights, and trap success and species diversity were calculated using Shannon’s index. At each site, the distance to trafficable roadways and water sources, vegetation composition, and the percent groundcover, canopy cover, and understory were measured. The cameras captured nine species and recorded a total of 398 trap events. Linear regression was …

A Test Of Rad Capture Sequencing On Ethanol-Preserved Centennial And Contemporary Specimens Of Philippine Fishes, Madeleine I. Kenton

Biological Sciences Theses & Dissertations

Understanding the relationship between ecological characteristics and genetic change in natural populations in different time scales can reveal how anthropogenic stressors affect natural populations and can improve the success of conservation strategies. The purpose of the Philippines Partnerships for International Research and Education (PIRE) project is to examine levels of genetic change between historical fish samples collected by the USS Albatross expedition in the early 1900s in the Philippines and contemporary populations collected at the same localities. This study tests genetic protocols to process historical and contemporary DNA for simultaneous comparison. Two DNA library preparation methods, single digest RADseq (“un-baited” …

The Natural History Of The Marsh Rice Rat, Oryzomys Palustris, In Eastern Virginia, Robert K. Rose

Biological Sciences Faculty Publications

The marsh rice rat, Oryzomys palustris, is a common rodent in tidal marshes of eastern Virginia, including those on the barrier islands. It also is present in grassy old fields in upland habitats in the coastal plain and parts of the piedmont of Virginia. This report summarizes what has been learned in recent decades about the population biology of this species in Virginia, including aspects of behavior, density, diet, distribution, genetics, habitats, mammal associates, and reproduction.

A Synergistic Approach For Evaluating Climate Model Output For Ecological Applications, Rachel D. Cavanagh, Eugene J. Murphy, Thomas J. Bracegirdle, John Turner, Cheryl A. Knowland, Stuart P. Corney, Walker O. Smith Jr., Claire M. Waluda, Nadine M. Johnston, Richard G. J. Bellerby, Eileen E. Hofmann

CCPO Publications

Increasing concern about the impacts of climate change on ecosystems is prompting ecologists and ecosystem managers to seek reliable projections of physical drivers of change. The use of global climate models in ecology is growing, although drawing ecologically meaningful conclusions can be problematic. The expertise required to access and interpret output from climate and earth system models is hampering progress in utilizing them most effectively to determine the wider implications of climate change. To address this issue, we present a joint approach between climate scientists and ecologists that explores key challenges and opportunities for progress. As an exemplar, our focus …

Does Pitcher Plant Morphology Affect Spider Residency?, Marc A. Milne, Deborah A. Waller

Biological Sciences Faculty Publications

Spiders are often found as residents in association with Sarracenia purpurea ( Purple Pitcher Plant). Many spiders choose web locations based on environmental cues such as vegetation structure and composition, prey density, temperature, and humidity. To determine if spiders use cues from the Purple Pitcher Plant to build their webs, we conducted a field study using variants of the plant that separated various morphological features: nectar, pigment, and the presence of prey. There was no difference in spider residency across all treatments and no difference in male/female or mature/immature residency. Linyphiids were the most common residents, possibly due to pitcher …

Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones

OES Faculty Publications

Life history scans of fish otoliths are bringing new insight into the structure, connectivity, and movement of fish populations. Data obtained from such scans, however, possess in-herent limitations that have not yet been fully addressed or understood. For example, several investigators have noted delays in otolith elemental uptake that do not appear to reflect habitat exposure. We hypothesized that the 3-dimensional structure of otoliths may produce sampling artifacts in the results obtained from laser ablation scans. To test this hypothesis, we sampled sagittal otoliths from juvenile Atlantic croaker Micropogonias undulatus with laser ablation inductively coupled plasma mass spectrometry to obtain …

The Likelihood Of Extinction Of Iconic And Dominant Herbivores And Detritivores Of Coral Reefs: The Parrotfishes And Surgeonfishes, Mia T. Comeros-Raynal, John H. Choat, Beth A. Polidoro, Kendall D. Clements, Rene Abesamis, Matthew T. Craig, Muhammad E. Lazuardi, Jennifer Mcilwain, Andreas Muljadi, Robert F. Myers, Cleto L. Nanola Jr., Shinta Pardede, Luiz A. Rocha, Barry Russell, Jonnell C. Sanciangco, Brian Stockwell, Heather Harwell, Kent E. Carpenter

Biological Sciences Faculty Publications

Parrotfishes and surgeonfishes perform important functional roles in the dynamics of coral reef systems. This is a consequence of their varied feeding behaviors ranging from targeted consumption of living plant material (primarily surgeonfishes) to feeding on detrital aggregates that are either scraped from the reef surface or excavated from the deeper reef substratum (primarily parrotfishes). Increased fishing pressure and widespread habitat destruction have led to population declines for several species of these two groups. Species-specific data on global distribution, population status, life history characteristics, and major threats were compiled for each of the 179 known species of parrotfishes and surgeonfishes …

Ecology Of Tenodera Sinensis And Tenodera Angustipennis (Mantodea: Mantidae) In Eastern Virginia, Cory A. Gall

Biological Sciences Theses & Dissertations

My study, conducted on the Wildlife Refuge located on Virginia's Eastern Shore, focused on the life history, ecology, and intra- and interspecies interaction of Tenodera sinensis and T. angustipennis. Field methods included capture-mark-recapture, species, sex, and developmental life stage identification, and recorded key developmental milestones. Also, to analyze food-limiting growth, a laboratory cohort was fed ad lib, with lab and field cohorts measured bi-weekly and their mean weekly growth was compared.

When compared to a lab cohort, Tsinensis field mantises were shown not to be growth limited by the abundance of prey. In 2011, the dates of several developmental stages …

Effects Of Gypsy Moth Outbreaks On North American Woodpeckers, Walter D. Koenig, Eric L. Walters, Andrew M. Liebhold

Biological Sciences Faculty Publications

We examined the effects of the introduced gypsy moth (Lymantria dispar) on seven species of North American woodpeckers by matching spatially explicit data on gypsy moth outbreaks with data on breeding and wintering populations. In general, we detected modest effects during outbreaks: during the breeding season one species, the Red-headed Woodpecker (Melanerpes erythrocephalus), increased over pre-outbreak levels, while during the winter one species, the Yellow-bellied Sapsucker (Sphyrapicus varius), increased and one, the Downy Woodpecker (Picoides pubescens), decreased from pre-outbreak levels. Responses following outbreaks were similarly variable, and in general we were unsuccessful …

A Comparison Of Adrenal In Toad-Eating And Nontoad-Eating Snakes, Shabnam Mohammadi

Biological Sciences Theses & Dissertations

Toads are chemically defended by bufadienolides, a class of cardiotonic steroids lethal to most predators, including many snakes. Bufadienolides bind to Na+K +-ATPase, inhibiting their ability to transport ions. In cardiocytes, this inhibition cause arrhythmia and severely increased contraction strength, which, if prolonged, lead to death. However, several snakes are resistant to bufadienolides and consume toads with no ill effects. Adrenal glands produce hormones that are important for the maintenance of Na+K +ATPase, and may therefore play an important role in countering the negative effects of bufadienolides. Indeed, the toad-eating specialist Heterodon platirhinos has been known to possess enlarged, and …

Interisland Variability Of Dune Plant Community Structure On Virginia's Barrier Islands, Justin K. Shafer

Biological Sciences Theses & Dissertations

The barrier islands of the Virginia Coast Reserve LTER site provide an opportunity to study interisland variability of dune plant communities. My research focused on the variation in biomass and diversity of communities among islands and dune positions. Grassy dunes of young, intermediate and old age were sampled on Smith, Hog, and Parramore Islands. Aboveground biomass was obtained from harvest plots, and roots were extracted from cores. Data were collected on depth to groundwater and total soil nitrogen. Variation in mean aboveground biomass was evident among the islands with the highest values on Hog Island, followed by Smith, then Parramore …

Patterns Of Spiny Lobster (Panulirus Argus) Postlarval Recruitment In The Carribbean: A Crtr Project, Mark J. Butler Iv, Angela M. Mojica, Eloy Sosa-Cordero, Marines Millet, Paul Sanchez-Navarro, Miguel A. Maldonado, Juan Posada, Bladimir Rodriguez, Carlos M. Rivas, Adrian Oviedo, Marcio Arrone, Martha Prada, Nick Bach, Nilda Jimenez, Maria Del Carmen Garcia-Rivas, Kirah Forman, Donald C. Behringer Jr., Thomas Matthews, Claire Paris, Robert Cowen

Biological Sciences Faculty Publications

As part of the Coral Reef Targeted Research (CRTR) Program, a partnership between the Global Environment Facility and the World Bank, our research team examined the recruitment patterns of Caribbean spiny lobster (Panulirus argus) postlarvae among regions in the Caribbean, with a particular focus on Mesoamerica. Our goal was to collect comparable information on postlarval supply among regions and to provide data to test predictions of connectivity generated from a coupled biophysical oceanographic model of lobster larval dispersal. Here we present the results of the postlarval recruitment monitoring program. We monitored the catch of postlarvae on Witham-style collectors …

Low-Density Rodent Communities In Eastern Virginia, Robert K. Rose, Jean F. Stankavich

Virginia Journal of Science

Two communities of small mammals were live trapped every other week for 15 months in linear oilfield habitat bordered by forested swampland in eastern Virginia. All nine species of the rodent community were present, mostly in low numbers and often intermittently. All species were characterized by high transiency, with a minority of marked animals becoming resident. Despite high trappability, all but two species in these communities had extremely low densities, suggesting that most species could not sustain populations via in situ reproduction.

Population Ecology Of The Golden Mouse, Robert K. Rose

Biological Sciences Faculty Publications

An understanding of the population dynamics of a species requires knowledge of the major life-history parameters of a population, including age at maturity, distribution of age classes, and lifetime reproductive contribution of the sexes, sex ratio, length of the breeding season, mean litter size, rates of growth and survival, and life span. Because few long-term studies have been conducted with Ochrotomys nuttalli as the focal species of investigation, only fragmentary information is available for many population parameters. As importantly, densities of golden mice often are low, making them difficult to evaluate statistically. Little has been published on age at maturity …

Fine Root Vitality And Its Application In A Minirhizotron Study Of A Co2 Enrichment In A Florida Scrub Oak Ecosystem, Brandon Todd Herbert

Biological Sciences Theses & Dissertations

Minirhizotron images are assigned color codes to approximate the age of individual roots in situ. Triphenyl-tetrazolium chloride (TTC) has been used to measure the vitality of plant tissue by detecting dehydrogenase activity. TTC was used to assess the vitality of root tissue by color in a scrub oak ecosystem at Kennedy Space Center in central Florida. Roots were excavated, sorted into four color classes and stained with TTC. The product of the reduction of TTC by dehydrogenase enzyme, formazan, was extracted and its absorbance recorded using a spectrophotometer. A significant difference (p2 enrichment being conducted on a scrub oak …

Anting Behavior In Birds: Ant Selection And Effect Of Ant Chemistry On Feather Ectoparasites, Hannah Carrington Revis

Biological Sciences Theses & Dissertations

Active anting behavior occurs when songbirds apply ants to their feathers. During anting displays, a bird draws its wings forward in front of the head and swings its tail around to the far right or left. Both wing and tail feathers are then rubbed with ants held in the bird's beak. The potential associations among ants, feather ectoparasites and birds make anting behavior an important community-level interaction. Although this behavior is cosmopolitan in distribution and occurs in a wide variety of passerine birds, it remains poorly understood. This dissertation tested hypotheses about anting behavior through controlled experiments with captive songbirds …

Summer Vertical Phytoplankton Distribution In The Lower Chesapeake Bay, Mollie Jill Weinstein

Biological Sciences Theses & Dissertations

Autotrophic picoplankton and phytoplankton composite samples were collected from the surface, pycnocline, and bottom water layers at three stations in the lower Chesapeake Bay between June and September 1993. Using light microscopy a total of 170 phytoplankton taxa were identified. Utilizing epifluorescent microscopy, the picoplankton taxa were distinguished by size, representing species with cells less than 2 microns. Diatoms were the dominant taxa during this period, with lesser representation by the other phytoplankton components. Within the picoplankton category, cyanobacteria were dominant. Statistical analyses of the data indicated the vertical composition and abundance of the phytoplankton was not significantly different over …

The Effect Of Nitrogen Fertilization On Short-Term Fine Root Dynamics In A Barrier Island Dune Community, John Walter Hutton

Biological Sciences Theses & Dissertations

Fine root dynamics are an important yet poorly understood component of terrestrial ecosystems. In recent years a number of researchers have focused on fine root dynamics; their work has looked at patterns across one or multiple growing seasons on a scale of monthly measures. The purpose of this study was to add to the overall understanding by looking at fine root dynamics on a shorter temporal scale. Minirhizotron observation tubes were used to assess the effect of nitrogen fertilization on short-term fine root dynamics in a nutrient limited, barrier island dune system. Root length elongation and mortality rates followed expected …

Comparative Taphonomy And Paleoecology Of A Glaciomarine Fauna, Carboniferous (Westphalian- Namurian) La Capilla Fm., Argentina, Rex A. Hanger, Mohutsiwa Gabadirwe

Virginia Journal of Science

The Carboniferous La Capilla Fm. of the Calingasta-Uspallata basin of western Argentina contains a low diversity fauna inhabiting a continental shelf under glacial ice fronts advancing from the east. Distal glaciomarine sediments on these ice-influenced shelves of Gondwana are most commonly interpreted as being deposited under quiet, low-energy conditions. Ta­phonomic and paleoecologic analysis of a sample of the fauna reveals the following: low species richness, yet comparable equitability to coeval, tropi­cal faunas; low articulation ratios and high pedicle valve dominance for brachiopods; diverse corrasion modes, about half relatively high categories; one hundred percent fracturing of brachiopod shells, with carinate fracture …

Possible Predation Scars On Rectithyris Subdepressa (Stoliczka, 1872), Late Cretaceous (Maastrichtian) Kallankurichi Fm., India, Rex Alan Hanger, Rama Krishnaswamy

Virginia Journal of Science

A single specimen of the terebratulid brachiopod, Rectithyris subdepressa (Stoliczka, 1872) from the Late Cretaceous (Maastrichtian) Kallankurichi Fonnation of southern India was found with durophagous predation traces. This occurrence is significant as it is possibly the first documentation of elasmobranch shark predation on brachiopods from the Mesozoic.

Ecology Of The Eastern Cottonmouth (Agkistrodon P. Piscivorus) At Back Bay National Wildlife Refuge: A Comparative Study Of Natural And Anthropogenic Marsh Habitats, Chad Lee Cross

Biological Sciences Theses & Dissertations

Mark-recapture sampling and radiotelemetry were used to investigate populations of the eastern cottonmouth, Agkistrodon p. piscivorus, in both natural and anthropogenic marsh habitats at Back Bay National Wildlife Refuge (BBNWR), Virginia Beach, Virginia from autumn 1995 to late spring 1998. Mark-recapture subjects were captured, marked by ventral scale-clipping, and released back into the population. A modified Schnabel Census estimator was used to estimate population sizes and corresponding densities in both marsh systems based on a total of 244 captures of 222 individuals. Most snakes were found >0.05 in from water, but it was apparent that proximity to water played …

Ecological Relationships Between The Marsh Rice Rat (Oryzomys Palustris) And The Meadow Vole (Microtus Pennsylvanicus) In Two Virginia Tidal Marshes, Christopher P. Bloch

Biological Sciences Theses & Dissertations

Small mammals were trapped for 23 months on two live trap grids in tidal marshes in Northampton County, on the Eastern Shore of Virginia, to examine ecological relationships between the marsh rice rat (Oryzomys palustris) and the meadow vole (Microtus pennsylvanicus). Population density, survival rates, capture probability, recruitment, residence time, and home range size were calculated for each species. Patterns of reproductive activity and fluctuations in mean weight were also observed.

There were considerable differences in population dynamics between the two sites. At Grid 2, where vegetative cover was more abundant, population densities of rice rats and meadow voles …

Pseudoreplication Revisited, Robert A. Heffner, Mark J. Butler Iv, Colleen Keelan Reilly

Biological Sciences Faculty Publications

No abstract provided.

The Diet Of Oryzomys Palustris Based On Stomach Content Analysis, Shannon L. Wright

Biological Sciences Theses & Dissertations

Oryzomys palustris (Harlan) is unusual in that it is one of two carnivorous mammals in the Family Muridae in North America. A diet analysis of Oryzomys palustris. the marsh rice rat, was done based on stomach contents. This was accomplished by taking the animals from two study areas located on the Eastern Shore of Virginia. The animals were taken monthly for one year. Once caught, the animals were sacrificed and their stomach contents were identified to the lowest taxonomic level possible. This study showed that rice rats were omnivorous mammals, eating a variety of foods, including dicots, monocots, crabs, …

Eutrophication And Macrobenthic Communities Of The Lower Chesapeake Bay: Effects Of Organic Enrichment In Pocomoke Sound, Saxis Virginia, Janice D. Mcdonnell

Biological Sciences Theses & Dissertations

The effects of organic enrichment on benthic community structure were evaluated in a field study conducted in Pocomoke Sound in the vicinity of a seafood processing plant. The empirically derived Species Abundance and Biomass (SAB) curves of Pearson and Rosenberg (1978) were used to model patterns of organic enrichment at the study site, called Pig Point, as well as two reference sites located within Pocomoke Sound. The Split Moving Windows (SMW) method was used to detect the ecotone point as defined in the Pearson and Rosenberg (1978) model and the Two Term Local Quadrat Variance (TTLQV) method was used to …

An Autecological Study Of Pyxidanthera Barbulata In The Blackwater Ecologic Preserve Virginia, John Marc Lowenthal

Biological Sciences Theses & Dissertations

Pyxidanthera barbulata (pyxie moss), a rare and endangered subshrub, has been found in decreasing numbers in it's "pine barren" habitat. An autecological study encompassing vegetation association analysis and environmental measurements was performed in the Blackwater Ecologic Preserve, its only known location in Virginia. The preserve is being subjected to controlled burning and the effect of burning on the species was evaluated. A multivariate analysis of variance was performed to identify species associations, and simple analysis of variance was done to find trends in the environmental data. Four taxa were positively associated with P. barbulata, Gaultheria procumbens, Vaccinium tenellum, Cladonia spp., …

The Remipedia (Crustacea): A Study Of Their Reproduction And Ecology, Jill Yager

Biological Sciences Theses & Dissertations

Remipedes are an unusual group of troglobitic crustaceans that live exclusively in anchialine caves. Since their discovery in 1979, nine species have been described, seven of which are found in caves in the West Indies, one from the Yucatan peninsula of Mexico and one from the Canary Islands. Most of what is known about these animals has come mainly from taxonomic descriptions. Little has been published about their reproductive biology or ecology. The objectives of this dissertation were to investigate the reproductive biology and ecology of the remipedes inhabiting Sagittarius Cave on Grand Bahama Island, Bahamas.

Sagittarius Cave was chosen …

An Evaluation Of Small Rodents In Four Dismal Swamp Plant Communities, F. Elizabeth Breidling, Frank P. Day Jr., Robert K. Rose

Biological Sciences Faculty Publications

Diversity and density of small rodents in the Dismal Swamp are believed to be low. Reasons for this may be excessive predation, heavy interspecific pressure from large rodents, lack of suitable habitat, low food availability or flooding.

Rodent populations were evaluated using live-traps and pitfall traps in four different Dismal Swamp plant communities. Habitat was compared on the basis of phytomass studies previously reported. Flood levels were recorded during live-trapping sessions. Mast from trees was collected in modified mast collectors, and fed to Peromyscus leucopus in the laboratory.

Only two small rodent species were captured: Ochrotomys nuttalli and Peromyscus leucopus …

An Ecological Study Of The Troglobitic Cirolanid Isopod Antrolana Lira Bowman From Madisons Saltpetre Cave And Stegers Fissure, Augusta Co., Virginia, T. Lynn Collins

Biological Sciences Theses & Dissertations

An ecological study of the troglobitic cirolanid isopod, Antrolana lira Bowman, was begun in August 1979 and continued through September 1980. The isopod is restricted to two phreatic lakes in Madisons Saltpetre Cave and one phreatic lake in nearby Stegers Fissure, Augusta Co., Virginia.

All three phreatic lakes were scuba dived and surveyed. No direct connections were found between the lakes. However, physical similarities suggest that the lakes are made up of the same body of phreatic water.

Random samples were taken monthly and seasonally from the east lake in Madisons Saltpetre Cave and the lake in Stegers Fissure. Specimens …

A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge

Biological Sciences Theses & Dissertations

Community structures of phytoplankton populations from the southern portion of the Chesapeake Bight were examined and associated to real and environmental spaces. The sampling design was specifically intended to examine the small scale three dimensional structure of the Chesapeake Bay plume as characterized by its phytoplankton populations. The phytoplankton were sampled at 101 stations, non-synoptically, over a five day period in mid-June, 1980.

Several multivariate numerical techniques were used to determine the relationships between the phytoplankton species distributions and pattern the low salinity plume distribution. A pattern of distribution which approximated the salinity plume resulted from several clustering procedures. Environmental …