Life Sciences Commons^™

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, …

Brown-Headed Cowbird (Molothrus Ater) Range Expansion Into The Southeast: Effects On The Passerine Populations Using North American Breeding Bird Survey Data, Elizabeth Pruitt Henderson

Biological Sciences Theses & Dissertations

North American Breeding Bird Survey data that were collected from 1971-1992 in Virginia, North Carolina, south Carolina, Georgia, Florida, Alabama and Tennessee were used in this analysis of the impact of Brown-headed Cowbird range expansion on four warbler and four vireo host species.

Maps of mean cowbird abundances were produced using kriging for the periods 1971-1975, 1976-1980, 1981-1985, 1986-1990 and 1991-1992. These maps illustrated a complex invasion of the southeastern United States by Brown-headed Cowbird.

Linear regression analyses of host and cowbird abundances within physiographic strata, showed no species to be in decline or increasing in abundance over the entire …

Recruitment Of Blue Crab, Callinectes Sapidus, Postlarvae To The Back-Barrier Lagoons Of Virginia's Eastern Shore, Robert D. Brumbaugh

OES Theses and Dissertations

Most research on the early life history of the blue crab, Callinectes sapidus, has been conducted in large partially stratified estuaries such as the Chesapeake Bay. In contrast, little is known about the recruitment dynamics or habitat requirements of blue crab postlarvae (megalopae) in shallow well-mixed lagoonal systems that make up a considerable part of the species' range. In Virginia's coastal lagoons, planktonic blue crab megalopae are most abundant at night on flooding tides, and are not abundant during the daytime or on ebbing tides. This appears to enhance retention within the lagoons, despite the short residence time of water …

Modeling Diseased Oyster Populations. Ii. Triggering Mechanisms For Perkinsus Marinus Epizootics, Eric N. Powell, John M. Klinck, Eileen E. Hofmann

CCPO Publications

Densities of Crassostrea virginica remain high enough to support substantial fisheries throughout the Gulf of Mexico despite high mortality rates produced by the endoparasite Perkinsus marinus. The infrequency of epizootics in these populations suggests that controls exist on the disease intensification process. The progression of epizootics in oyster populations, the factors that trigger epizootics, and the factors that terminate epizootics once started were investigated with a coupled oyster population—P. marinus model.

The time development of a simulated epizootic was triggered by environmental conditions that occurred and disappeared as much as t8 months prior to the onset of mortality in …