Ecology and Evolutionary Biology Commons^™

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 …

The Annual Reproductive Cycle Of Oryzomys Palustris In A Virginia Tidal Marsh, Erin A. Dreelin

Biological Sciences Theses & Dissertations

The objectives of my study were to determine when the marsh rice rat (Oryzomys palustris) begins and ends reproduction during the year, if there are seasonal changes in litter size, and the weight at which sexual maturity is reached. Monthly samples of rice rats were trapped from May 1995 to May 1996 in Northampton County, Virginia. Rice rats were trapped with Fitch live traps, euthanized in the field, and brought to the lab for necropsy. Data from two other studies of rice rats in Northampton County were also examined. Potential breeders did not reproduce with equal intensity throughout the …

Habitat Selection, Population Density, And Home Range Of The Elf Owl, Micrathene Whitneyl, At Santa Ana National Wildlife Refuge, Texas, Christopher Michael Gamel

Theses and Dissertations - UTB/UTPA

The Elf Owl, Micrathene whitneyi, is a regular summer resident of the southwestern United States. My objectives were to collect information concerning habitat selection, home range size, and population density of M. w. idonea, the subspecies occurring in the Lower Rio Grande Valley of Texas. Nocturnal surveys indicated greater use of chaparral habitat (92%) compared to riparian woodlands (8%). Utilized habitat was characterized by highest foliage density at 2.5-3.0 m, with a partial canopy at 3.8 $\pm$ 0.36 m and a semi-open understory. Home range size ranged from 0.24 to 2.6 ha, with a mean of 1.05 $\pm$ 0.33 ha. …

Habitat Use And Activities Of The Piping Plover, Charadrius Melodus, Wintering On South Padre Island, Texas, Humberto Garza Jr.

Theses and Dissertations - UTB/UTPA

The Piping Plover, Charadrius melodus, is endangered in its breeding sites and threatened in its wintering sites. This migratory shorebird spends 3 to 4 months on northern U.S. and southern Canadian breeding sites and the remainder of the year in Gulf of Mexico, Caribbean, and southern U.S. wintering sites. Up to 2.4% of the estimated Piping Plover population remains for the 9 to 10 month non-breeding season on South Padre Island (S.P.I.). During the non-breeding season, I conducted censuses at 15 sites in the southern portion of South Padre Island to determine Piping Plover habitat preferences. Piping Plovers prefer bay …

Ecology Of The Early Life History Of The Caribbean Spiny Lobster, Panulirus Argus: Recruitment, Predation, And Habitat Requirements, Charles A. Acosta

Biological Sciences Theses & Dissertations

Recruitment variability of the early life history stages of marine benthic organisms can have profound consequences on population dynamics. I studied factors affecting recruitment success of postlarvae and early juveniles of the Caribbean spiny lobster. I examined patterns in postlarval supply, investigated wind forcing as a potential transport mechanism for recruiting postlarvae, and quantified predation on postlarvae in south Florida, USA. In an eight-year time series, spiny lobster postlarval supply occurred year-round between the new and first quarter lunar phases. The major annual peak occurred around March corresponding to spawning activity ten months earlier, and a smaller non-seasonal peak occurred …

The Effects Of Habitat Fragmentation And Factors Influencing Nest Box Use On The Southern Flying Squirrel (Glaucomys Volans) In Southern Illinois, Catherine J. Woodworth

Masters Theses

I studied the effects of habitat :fragmentation on the southern flying squirrel (Glaucomys volans) in 30 forest fragments in southern Illinois. The fragments ranged in size from 6 ha to 5264 ha, and had varying degrees of isolation. I placed 10 nest boxes in each habitat fragment and checked them monthly. I captured southern flying squirrels in 24 of the 30 fragments, and found evidence of squirrels (i.e., nests and feeding stations) in 4 additional fragments. Thus, only 2 fragments did not show any evidence of squirrel use suggesting that the southern flying squirrel may not be particularly …

Roost Site Selection Of The Red Bat (Lasiurus Borealis), Kenneth J. Mager

Masters Theses

I monitored the roosting activity and evaluated roost site selection of red bats (Lasiurus borealis) at study sites in Coles County during the summer of 1996. Red bats were mist-netted and radio transmitters were affixed to 12 individuals. A total of 105 transmitter-days were recorded with 75 roost locations identified. The roost types consisted of eight different species of trees, prairie grass, and residential structures but the vast majority of roosts (92%) were in large, deciduous trees. The height of the roosts ranged from 0.5 to 21.4 m, but 54.7% were between 5-10 m. Movement between consecutive roosts ranged from …

Distribution Of Free Marine Viruses Of Lower Chesapeake Bay And Their Effects On Life-History Parameters Of The Estuarine Copepod Acartia Tonsa Dana, Lisa A. Drake

OES Theses and Dissertations

Naturally occurring viruses are very abundant in fresh, estuarine, and marine waters, with densities on the order of 10⁵-10⁸ viruses ml^-1. Research has focused on virus effects on bacteria, cyanobacteria, and phytoplankton, as well as mechanisms of virus production and decay. However, little is known about the distribution of viruses in benthic environments or virus effects on organisms in higher trophic levels.

To determine the distribution of virus-like particles (VLPs) and bacteria in the lower Chesapeake Bay, vertical profiles of VLPs and bacteria were determined through the water column and 15-25 cm into the sediment …