Virginia Population Research Articles

Similar offspring production by normal and intersex females in two populations of Gammarus minus (Malacostraca, Amphipoda) with high levels of intersexuality

Two Virginia (U.S.A.) populations of the freshwater amphipod Gammarus minus (Say, 1818) exhibit high frequencies of females with male genital papillae (60 to 75% in one population and 100% in the other) that have been observed for over 30 years. This observation is surprising because sex-allocation theory predicts that such intersex individuals should have lower evolutionary fitness than ‘normal’ males or females. Here we tested this theory by comparing a major component of reproductive fitness (offspring production, as estimated by number and total mass of offspring in a brood) between intersex and normal females. Although intersex females tend to brood slightly fewer, but larger embryos than those of normal females, these differences were not significant overall, and moreover they resulted in nearly identical mean production of total offspring mass per brood. Maternal somatic investment (body mass and body condition) during brooding also did not differ significantly between intersex and normal females. These results suggest that intersex females may not have lower reproductive fitness than that of normal females, which may help explain their high frequencies in the Virginia populations. Consistent with this hypothesis, available literature data on four amphipod species show a positive association between intersex frequency and the offspring production of intersex females relative to that of normal females. However, this hypothesis needs to be tested further by examining other reproductive and survival traits related to fitness, and by examining other amphipod populations with varying intersex frequencies. Moreover, the cause(s) of the intersex condition in the Virginia populations (and most other amphipod populations) remains largely unknown.

Picturing the Climate: Radiologic Assessment of Rwandan Imaging Capacity

INTRODUCTION The influence of radiology in resource-limited settings has been variably addressed in international public health initiatives to date. Yet as the face of global public health changes, marked by an increasing percentage of worldwide disability-adjusted lifeyears attributable to chronic diseases, cancers, and injuries, the development of imaging into centralized health infrastructure has been and will be integral for medical progress. Rwanda is a small sub-Saharan, East African nation with the landmass of Maryland and the population of Virginia, approximately 11 million people. The country is bordered by the Democratic Republic of Congo, Uganda, Tanzania, and Burundi. The population is largely agricultural workers, with more varied occupations within the capital, Kigali. According to the World Bank, the gross national income per capita was reported as US $440 in 2008 [1]. The genocide of 1994 leveled the Rwandan health care infrastructure, including all radiographic services. Beginning in August 1994, the Australian Medical Support Force provided the first basic imaging as part of rebuilding the nation [2]. In the subsequent five years of the reconstruction period, more complex programs and provision of supplies were primarily the domain of foreign aid organizations. Since that time, Rwanda has experienced significant progress in rebuilding its health care infrastructure, evidenced by its membership in a select group of nations that are

Intraspecific variation in Podostemum ceratophyllum (Podostemaceae): evidence of refugia and colonization since the last glacial maximum

Intraspecific variation among 20 populations of Podostemum ceratophyllum Michx. was investigated to test the hypothesis of range expansion from southern refugia since the last glacial maximum. Six noncoding regions of chloroplast DNA were sequenced in 60 individuals. Populations were divided into two groups, north and south of the glacial boundary, in addition to isolated populations in Arkansas and Honduras. Variation in populations north of the boundary was compared with variation in populations to the south and in the isolated populations. Nucleotide diversity was an order of magnitude lower in populations north of the glacial boundary than in those to the south. The Arkansas and Honduras populations showed no variation. The predominant haplotype in northern populations was also found in a Virginia population. Reduced variation north of the glacial boundary suggests a founder event associated with range expansion since the last glacial maximum. Colonization probably occurred from populations in refugia located several hundred kilometers south of the glacial boundary. The results provide insight into the effects of past and current climate change on patterns of geographic distribution and genetic variation in aquatic plants.

Lessons Learned from Efforts to Restore Oyster Populations in Maryland and Virginia, 1990 to 2007

A century-long decline of the fishery for the Eastern oyster Crassostrea virginica (Gmelin, 1791) in Maryland and Virginia stimulated numerous efforts by federal, state, and nongovernmental agencies to restore oyster populations, with limited success. To learn from recent efforts, we analyzed records of restoration and monitoring activities undertaken between 1990 and 2007 by 12 such agencies. Of the 1,037 oyster bars (reefs, beds, or grounds) for which we obtained data, 43% experienced both restoration and monitoring, with the remaining experiencing either restoration or monitoring only. Restoration activities involved adding substrate (shell), transplanting hatchery or wild seed (juvenile oysters), bar cleaning, and bagless dredging. Of these, substrate addition and transplanting seed were common actions, with bar cleaning and bagless dredging relatively uncommon. Limited monitoring efforts, a lack of replicated postrestoration sampling, and the effects of harvest on some restored bars hinders evaluations of the effectiveness of restoration activities. Future restoration activities should have clearly articulated objectives and be coordinated among agencies and across bars, which should also be off limits to fishing. To evaluate restoration efforts, experimental designs should include replication, quantitative sampling, and robust sample sizes, supplemented by pre- and postrestoration monitoring.

Effects of anthropogenic activities on genetic diversity and population structure of American ginseng ( Panax quinquefolius L.) growing in West Virginia

Using random amplified polymorphic DNA (RAPD) markers, genetic variation and population structure of wild and cultivated American ginseng growing in West Virginia (WV) was assessed. Also, the effects of cultivation intensity and harvest pressure on genetic diversity of ginseng populations were evaluated. Eight primers were used to amplify DNA samples from 468 plants, generating a total of 98 band fragments of which 84 were polymorphic. Overall mean genetic diversity measures were lower in West Virginia populations compared to populations from Pennsylvania and Wisconsin. Among West Virginia populations, mean genetic diversity indices were higher in cultivated than in wild populations but differences were not significant. Means of genetic diversity indices were higher in wild populations from low harvest pressure region [percent polymorphism (P) = 33.33%, Nei's (1973) gene diversity (H) = 0.1172, and Shannon’s index (I) = 0.1743] compared to those from high harvest pressure region (P = 28.27%, H = 0.1019, I = 0.1513), however, these indices were not significantly different (P > 0.05, Mann-Whitney test). Analysis of molecular variance (AMOVA) however showed significant genetic differentiation (P < 0.001) within and among wild populations (48.37 and 54.10% respectively). Cultivated ginseng populations from a region with low cultivation intensity had lower levels of genetic diversity indices (P = 29.93%, H = 0.0948, I = 0.1609) compared to populations from a region with high cultivation intensity (P = 60.60%, H = 0.2593, I = 0.3243), these indices were significantly different (P < 0.05, Mann-Whitney test). AMOVA further revealed that in cultivated populations, 53.68 and 42.11% of the total genetic variation was attributed to within and among population differentiation in regions respectively and 4.20% of genetic variation existed between regions. Based on this data, it is evident that genetic diversity of American ginseng is substantially increased with increase in its cultivation intensity. This can be ascribed to higher levels of gene flow associated with sourcing of seeds from various sources to meet cultivation needs of large scale growers. Even though genetic variability among populations experiencing different harvest pressure was not statistically significant in this study, the lower genetic diversity indices exhibited in wild populations from high harvest pressure regions underscores the potential impacts of harvesting pressure on genetic diversity of this medicinal plant. The data presented in this study will be useful in guiding conservation strategies for this economically important but threatened medicinal species. Key words: Cultivation intensity, harvest pressure, analysis of molecular variance (AMOVA), random amplified polymorphic DNA (RAPD).

Cyclocephala nigricollisBurmeister (Coleoptera: Scarabaeidae: Dynastinae: Cyclocephalini). What is It? and Where is It?

“Cyclocephala nigricollis” Burmeister is a relatively common species in some parts of the southern United States, with disjunct populations in Virginia and the Carolinas in the eastern United States. After examination of specimens and the literature, we conclude that C. nigricollis is a nomen dubium and that its neotype was invalidly proposed. Accordingly, Cyclocephala robusta LeConte, as the next available name, is the correct designation for this taxon.

Genetic Variation and Population Structure of Arabidopsis lyrata ssp. lyrata (Brassicaceae) along the Eastern Seaboard of North America

Arabidopsis lyrata ssp. lyrata is widespread but edaphically restricted, which suggests that the dispersal ability and level of genetic exchange among populations might be limited. We assessed levels of genetic diversity and population differentiation within and among six A. lyrata ssp. lyrata populations from along the eastern seaboard of the United States by examining variation at nine microsatellite loci among 233 individuals. These data were also evaluated to assess any relationship between geographic and genetic distance and correlation of genetic diversity with population size. Measures of genetic diversity across all 9 microsatellite loci were high in most populations. Genetic diversity, as measured by number of alleles, was generally higher in the Maryland and New York populations, as compared with the southern most sampled populations in Virginia. Genetic differentiation among regions was highly significant and large (FST = 0.47). This was supported by several analyses, suggesting that there is little gene flow among the regions sampled. There was a strong positive correlation between geographic and genetic distance, which is indicative of the pattern of isolation-by-distance. Population size correlated with the number of alleles within populations, supporting population genetic theory that larger populations harbor greater genetic diversity. Wright's FST and genetic structure analysis also provided evidence of genetic partitioning at small (<100 m) geographic distances between two areas sampled within one locality. These results indicate that the largest proportion of variation was explained by within population differences and may have implications for the conservation of this widespread but fragmented taxon.

Toward a Comprehensive Developmental Model for Alcohol Use Disorders in Men

The multiple risk factors for alcohol use (AU) and alcohol use disorders (AUDs) are interrelated through poorly understood pathways, many of which begin in childhood. In this report, the authors seek to develop an empirical, broad-based developmental model for the etiology of AU and AUDs in men. We assessed 15 risk factors in four developmental tiers in 1,794 adult male twins from the Virginia population based twin registry. The best fitting model explained 39% of the variance in late adolescent AU, and 30% of the liability to lifetime symptoms of AUD. AU and AUDs can be best understood as arising from the action and interaction of two pathways reflecting externalizing genetic/temperamental and familial/social factors. Peer group deviance was important in each pathway. Internalizing symptoms played a more minor role. Familial/social factors were especially important influences on AU, while genetic/temperamental factors were more critical for AUDs. We conclude that AU and AUDs in men are complex traits influenced by genetic, family, temperamental, and social factors, acting and interacting over developmental time.

Conservation genetics of a peripherally isolated population of the wood turtle (Glyptemys insculpta) in Iowa

The North American wood turtle, Glyptemys insculpta, is a semi-aquatic species that is considered rare, threatened, or endangered over much of its range. In this study, a particularly vulnerable peripheral isolate population in Iowa has been monitored over a period of 7 years. Population census size, estimated from mark-recapture data, and age structure determined from morphology are compared with genetic variation assessed using microsatellites. For reference, the genetics and demographics of this peripheral isolate are compared to data from a more dense population nearer the core of the species range in West Virginia. Geneflow between the Iowa population and a nearby population in Minnesota also is assessed. Genetic data indicate that the Iowa population is isolated, unique, and diverse. Although the Iowa population has lower allelic richness, lower heterozygosity, and smaller genetic effective population size than does the West Virginia population, the difference is not dramatic despite its lower population size, position at the periphery of the species range, and biogeographic history. The Iowa population is not inbred, and there is no genetic signature of a recent population bottleneck. However, interpretations of recent population dynamics based on genetic data may be unduly encouraging in long-lived species such as G. insculpta. Field data suggest a nearly complete lack of recruitment in Iowa. A number of environmental and anthropogenic factors, including recent increases in summer flooding during egg incubation, may have a more negative impact on the Iowa population than on the West Virginia population.

Dispersal and Within‐Stream Spatial Population Structure of Brook Trout Revealed by Pedigree Reconstruction Analysis

AbstractSpatial patterns of spawning and early dispersal have important implications for the population dynamics of stream‐dwelling salmonids, but the limitations of marking technology have made it difficult to measure these processes in wild populations. We used microsatellite DNA markers and sibship and parentage analyses to follow the dispersal, spatial distribution, and distribution of reproductive success in a small, isolated western Virginia population of brook trout Salvelinus fontinalis at 4, 16, and 28 months after fry emergence. For the 2004 year‐class (high‐recruitment cohort), we identified 180 full‐sibling families representing individual spawning events. Offspring were unevenly distributed across families, with 16% of the families accounting for 50% of the offspring and 53% of the families being represented by fewer than three individuals. However, a large proportion of adults had some successful reproduction. Spatial and family size distributions at 4 months after emergence were similar between the 2004 and 2006 (low‐recruitment) year‐classes in spite of a threefold difference in abundance. The spatial locations of full sibs were closely associated, indicating limited dispersal in the first 4 months postemergence. The spatial locations of assigned parents were correlated with the locations of their offspring. For the 2004 cohort, sibling dispersal substantially increased after the 4‐month sample, but neither fish length, family size (number of individuals), nor fish density was related to dispersal distance at any postemergence time interval. In this study, we demonstrate the ability of sibship and parentage analyses to reveal important aspects of brook trout population structure and movement. Our results suggest that limited dispersal by age‐0 brook trout and their parents results in a high level of within‐stream spatial population structure even in the absence of barriers to movement, and this must be accounted for in genetic surveys and management studies.

Avertable Deaths Associated With Household Income in Virginia

We estimated how many deaths would be averted if the entire population of Virginia experienced the mortality rates of the 5 most affluent counties or cities. Using census data and vital statistics for the years 1990 through 2006, we applied the mortality rates of the 5 counties/cities with the highest median household income to the populations of all counties and cities in the state. If the mortality rates of the reference population had applied to the entire state, 24.3% of deaths in Virginia from 1990 through 2006 (range = 21.8%-28.1%) would not have occurred. An annual mean of 12 954 deaths would have been averted (range = 10 548-14 569), totaling 220 211 deaths from 1990 through 2006. In some of the most disadvantaged areas of the state, nearly half of deaths would have been averted. Favorable conditions that exist in areas with high household incomes exert a major influence on mortality rates. The corollary-that health suffers when society is exposed to economic stresses-is especially timely amid the current recession. Further research must clarify the extent to which individual-level factors (e.g., earnings, education, race, health insurance) and community characteristics can improve health outcomes.

Response to Kelly Near and Ann Duesing’s letter: “Informatics Training for Public Health Practitioners”

Kelly Near and Ann Duesing have performed a great service by attempting to replicate the authors’ randomized controlled trial on the effects of training on information-seeking behavior among public health professionals [1]. They have served the profession even further by reporting in their letter the challenges that they encountered in replicating our study and for reporting their interesting yet divergent results [2]. We had recommended further replication of our study, because we asked important questions that trended toward the affirmative for the two hypotheses tested but could not be confirmed at the level of statistical significance. While Near and Duesing were able to use our practical advice in replicating our study, their letter suggests that differences in their population in southwestern Virginia and unexpected problems with administering a consistent incentive system for participants probably explain the differences between the two studies. We found that public health health care practitioners viewed PubMed as useful for answering their native questions. As reported elsewhere [3,4], our trainees anonymously highly valued their PubMed training in both immediate and follow-up evaluations two months later. We were intrigued that Near and Duesing did not make the same observation, which might have been due to the involvement of different populations. This additional discrepancy between the two studies also deserves further investigation with public health practitioner populations elsewhere. Evidence-based practice guidelines [5] indicate that our study currently offers the best evidence to support existing library or informatics training programs. Clearly, readers of the Journal of the Medical Library Association need to continue to offer training programs, unless later studies convincingly suggest otherwise. Our study suggests support for the two hypotheses. To test these hypotheses successfully, a future study will need to recruit enough participants to reach statistical significance, while providing all participants with equal incentives to submit their questions. Our study suggests that without incentives to submit questions, participants will not take the time away from their many work-related demands to fully record their questions. Near and Duesing’s study could not achieve equal status for incentives because of the decentralized local health system in southwestern Virginia. In contrast, a system capable of providing a consistent incentive and administrative system could ensure the existence of conditions conducive for a randomized controlled trial. The National Association of County and City Health Officials profiles of local health departments suggest that the states of Arkansas, Delaware, Florida, Mississippi, South Carolina, and Vermont have strong state-centric authority over local health departments [6]. These states possibly offer the potential for replication because these states could likely ensure consistent administration of incentives, although we encourage others to test our hypotheses in other contexts. Unified, large, urban-area public health departments represent other plausible environments for rigorously replicating our study successfully. We will gladly share our detailed study protocols and any pragmatic advice, as we did for Near and Duesing, with any interested colleagues to ensure that any replications conducted elsewhere proceed smoothly.

Sublethal Predation and Regeneration in Two Onuphid Polychaetes: Patterns and Implications

We examined sublethal predation in the polychaete Diopatra cuprea, an important ecosystem engineer of intertidal and shallow subtidal marine sediments in the western Atlantic. D. cuprea commonly loses its antennae and portions of its anterior to predator attacks; these lost body portions are subsequently regenerated. We asked (i) if the intensity of sublethal predation differs for D. cuprea populations in Virginia versus Florida, (ii) if sublethal predation varies temporally in each region, and (iii) if sublethal predation influences activity and tube-building rates. Within Florida, we also drew comparisons between D. cuprea and the closely related onuphid Americonuphis magna. Surprisingly, we found that sublethal predation is more intense in Virginia than in Florida, likely making substantial contributions to secondary productivity. Within Florida, A. magna experienced more antennal loss than D. cuprea and is incapable of anterior regeneration. D. cuprea activity and tube-building rates are strongly influenced by anterior loss, but more subtly influenced by antennal loss. Given the observed rates of sublethal predation and population densities in Virginia versus Florida, sublethal predation is an important factor influencing D. cuprea populations and their associated communities.

Genetic Analysis of an Unusual Population of the Problematic Tiger Beetle Group,Cicindela Spendida/C. Limbalis, from Virginia, U.S.A. (Coleoptera: Cicindelidae) Using MTDNA

Previous morphological studies within the claybank group of tiger beetles concluded that C. limbalis, C. splendida, and C. denverensis were separate species, but results from a limited mitochondrial DNA analysis suggested they may represent a single species. Here we review relevant literature on the relationships between C. limbalis and C. splendida and present results of mtDNA analysis of several populations of these taxa, including a Virginia population with specimens morphologically matching both species. Mitochondrial haplotypes for cob and coxl revealed that C. limbalis and C. splendida from several populations were closely related and could not be diagnosed under the criterion of exclusivity. Phylogenetic analyses were conducted under parsimony criteria and Bayseian inference, and in all reconstructions, C. limbalis and C. splendida (and a reference sample of C. denverensis) were united into a large polytomy. Nested clade analysis revealed no patterns of geographic distribution significantly different from panmixia. The lack of geographic structure across the sampled range recovered no support for earlier phylogeographic hypothesis that C. splendida and C. limbalis separated in the foothills of the Appalachians during the Pleistocene. It is hoped that these findings will provide impetus for a thorough systematic analyses of the claybank group of tiger beetles.

Assessing Allowable Take of Migratory Birds

ABSTRACT Legal removal of migratory birds from the wild occurs for several reasons, including subsistence, sport harvest, damage control, and the pet trade. We argue that harvest theory provides the basis for assessing the impact of authorized take, advance a simplified rendering of harvest theory known as potential biological removal as a useful starting point for assessing take, and demonstrate this approach with a case study of depredation control of black vultures (Coragyps atratus) in Virginia, USA. Based on data from the North American Breeding Bird Survey and other sources, we estimated that the black vulture population in Virginia was 91,190 (95% credible interval = 44,520‐212,100) in 2006. Using a simple population model and available estimates of life‐history parameters, we estimated the intrinsic rate of growth (rmax) to be in the range 7–14%, with 10.6% a plausible point estimate. For a take program to seek an equilibrium population size on the conservative side of the yield curve, the rate of take needs to be less than that which achieves a maximum sustained yield (0.5 × rmax). Based on the point estimate for rmax and using the lower 60% credible interval for population size to account for uncertainty, these conditions would be met if the take of black vultures in Virginia in 2006 was &lt;3,533 birds. Based on regular monitoring data, allowable harvest should be adjusted annually to reflect changes in population size. To initiate discussion about how this assessment framework could be related to the laws and regulations that govern authorization of such take, we suggest that the Migratory Bird Treaty Act requires only that take of native migratory birds be sustainable in the long‐term, that is, sustained harvest rate should be &lt;rmax. Further, the ratio of desired harvest rate to 0.5 X rmax may be a useful metric for ascertaining the applicability of specific requirements of the National Environmental Protection Act.

Locally adapted social parasite affects density, social structure, and life history of its ant hosts

Selection and adaptation are important processes in the coevolution between parasites and their hosts. The slave-making ant Protomognathus americanus, an obligate ant social parasite, has previously been shown to evolve morphological, behavioral, and chemical adaptations in the coevolutionary arms race with its Temnothorax hosts. Yet empirical studies have given variable results on the strength of the selection pressure this parasite exerts on its host populations. In this study, we directly investigated the pressure exerted by P. americanus and the reactions of the main host species, T. longispinosus, in two ant communities by manipulating parasite density in the field over several years. In addition, a cross-fostering design with the exchange of parasites between host populations allowed us to investigate local adaptation of parasite or host. We demonstrate a severe impact of the social parasite on the two host populations in West Virginia and New York, but also variation in host reactions between sites, as expected by the geographic mosaic theory of coevolution. Host density decreased at the West Virginia site with the presence of local slave-makers, whereas at the ecologically favorable New York site, density was unaffected. Nevertheless, social organization, colony size, and investment patterns of these host colonies at this site changed in response to our parasite manipulation. The release of P. americanus colonies led to a reduction in the number of resident queens and workers, an increase in intranest relatedness, and lower productivity, but also a higher investment in reproductives. In West Virginia, colony demography did not change, but raiding activity by New York slave-makers caused different investment patterns of host colonies. In addition, the cross-fostering element revealed local adaptation of the parasite P. americanus: slave-making colonies fared better in their sympatric host population, as they contained more slave-making ant workers and slaves at the end of our 27-month experiment.

Family History as an Indicator of Increased Risk for Food Allergy in Infants

RATIONALE: With rising prevalence of food allergy among patients between 0-3 years, we sought to examine predictors of food allergy among infants in Northern Virginia.METHODS: Retrospective charts and computerized medical records of 138 patients from Northern Virginia between the ages of 0-3 were reviewed. All patients held the diagnosis of IgE-mediated food allergy.RESULTS: Of patients diagnosed with food allergy, 70.8% exhibited symptoms of eczema as first sign of allergies. Egg allergy was present in 58.3% of patients followed by peanut (45.8%), milk (23.6%), wheat (6.9%) and soy (6.0%). Atopy (allergic rhinitis, asthma, food allergy) in 1 or both parents was present in 81.9% of patients. Allergic rhinitis in 1 or both parents was present in 66.7% of patients. Asthma in 1 or both parents was present in 23.6% of patients. History of food allergy in 1 or both parents was present in 20.8% of patients.CONCLUSIONS: Our analysis revealed that family history of allergic rhinitis was the strongest predictor of food allergy in patients between 0-3 years of age in the Northern Virginia population. Eczema was most often the first presentation of food allergy. Amongst the most highly allergic foods, egg was found to be the most common food allergen followed by peanut, milk, wheat and soy. We therefore conclude that parental history of atopy is a strong risk factor for the development of food allergy in infants. RATIONALE: With rising prevalence of food allergy among patients between 0-3 years, we sought to examine predictors of food allergy among infants in Northern Virginia. METHODS: Retrospective charts and computerized medical records of 138 patients from Northern Virginia between the ages of 0-3 were reviewed. All patients held the diagnosis of IgE-mediated food allergy. RESULTS: Of patients diagnosed with food allergy, 70.8% exhibited symptoms of eczema as first sign of allergies. Egg allergy was present in 58.3% of patients followed by peanut (45.8%), milk (23.6%), wheat (6.9%) and soy (6.0%). Atopy (allergic rhinitis, asthma, food allergy) in 1 or both parents was present in 81.9% of patients. Allergic rhinitis in 1 or both parents was present in 66.7% of patients. Asthma in 1 or both parents was present in 23.6% of patients. History of food allergy in 1 or both parents was present in 20.8% of patients. CONCLUSIONS: Our analysis revealed that family history of allergic rhinitis was the strongest predictor of food allergy in patients between 0-3 years of age in the Northern Virginia population. Eczema was most often the first presentation of food allergy. Amongst the most highly allergic foods, egg was found to be the most common food allergen followed by peanut, milk, wheat and soy. We therefore conclude that parental history of atopy is a strong risk factor for the development of food allergy in infants.

Influence of Acorn Mast on Allegheny Woodrat Population Trends in Virginia

Abstract Neotoma magister (Allegheny Woodrat) is a medium-sized rodent associated with rock outcrops, talus slopes, caves, cliffs, and boulder fields in the central and southern Appalachians and Allegheny Plateau physiographic provinces. It is currently classified as a G3G4 species and is considered threatened, endangered, or a species of concern in almost every state in which it occurs. As part of a 12-yr study on the status and distribution of the Allegheny Woodrat in Virginia, we collected data on woodrat ecology and population demographics. Herein, we investigate the relationship between acorn production and an index of woodrat abundance for several woodrat populations in Virginia. Woodrat population size was estimated using the Lincoln-Peterson index. Acorn mast surveys were conducted by the Virginia Department of Game and Inland Fisheries from 1989 to 2002 to index mast abundance. Woodrat population estimates were positively correlated (P < 0.05) to the previous year's mast crop index at 2 of 4 moni...

Subfloor pits and the archaeology of slavery in Colonial Virginia

This book discusses the daily life and culture of enslaved Africans and their descendants. Enslaved Africans and their descendants comprised a significant portion of colonial Virginia populations, with most living on rural slave quarters adjacent to the agricultural fields in which they labored. Archaeological excavations into these home sites have provided unique windows into the daily lifeways and culture of these early inhabitants. A common characteristic of Virginia slave quarters is the presence of subfloor pits be-neath the houses. The most common explanations of the functions of these pits are as storage places for personal belongings or root vegetables, and some contextual and ethnohistoric data suggest they may have served as West African-style shrines. Through analysis of 103 subfloor pits dating from the 17th through mid-19th centuries, Samford reveals how data on shape, location, surface area, and depth, as well as contextual analysis of artifact assemblages, can show how subfloor pits functioned for the enslaved. Archaeology reveals the material circumstances of slaves' lives, which in turn opens the door to illuminating other aspects of life: spirituality, symbolic meanings assigned to material goods, social life, individual and group agency, and acts of resistance and accommodation. Analysis of the artifact assemblages allows the development of hypotheses about how West African, possibly Igbo, cultural traditions were maintained and transformed in the Virginia Chesapeake.

The Effects of Derelict Blue Crab Traps on Marine Organisms in the Lower York River, Virginia

AbstractDerelict (abandoned or lost) traps targeting blue crab Callinectes sapidus have the potential to affect the blue crab fishery and other marine‐oriented species. We used side‐scan sonar to locate derelict traps and assess their extent and accumulation rate. Experimental traps were monitored at four locations to calculate catch rates of marine organisms and trap degradation rates. In 2006, 635–676 derelict traps were identified in a 33.5‐km2 area of the lower York River in Virginia's portion of the Chesapeake Bay. Trap loss rates are estimated at 30%, resulting in the potential addition of over 100,000 traps annually to the Chesapeake Bay derelict trap population in Virginia. The top four species captured in the experimental traps were blue crab, Atlantic croaker Micropogonias undulates, oyster toadfish Opsanus tau, and white perch Morone americana. Experimental derelict traps captured 50.6 blue crabs·trap−1·season−1 during April–November 2006 and 13.6 Atlantic croakers·trap−1·season−1 during May–August 2006. There was no difference in catch rates between traps of different ages. Baiting traps to simulate entrapped fish (self‐baiting) doubled the catch rate. Experimental derelict traps continued to capture organisms for at least 1 year, which suggests that derelict traps could affect blue crab populations.