Physical Sciences and Mathematics Commons^™

Food And Feeding Of Fishes From Magothy Bay, Virginia, Joseph J. Kimmel

OES Theses and Dissertations

No abstract provided.

Mechanisms Of Population Regulation In Confined Colonies Of Peromyscus Maniculatus (Wagner) And The Response To Exploitation, Donna Corn Olsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Wild-trapped and laboratory-reared Peromyscus maniculatus (Wagner) were raised as confined colonies indoors with various stocking densities ranging from 0.026 to 0.100 mice per sq. ft. in pens of 40, 77, and 154 sq. ft. The animals were individually tagged and all pens were censused at weekly or semi-monthly intervals to record animals present, body weights, food consumption, and overt reproductive condition. At the termination of each experiment, all mice were necropsied and organ weights of gonads and adrenals recorded. Histological sections were made of the testes and ovaries. Half the colonies were subjected to density-independent exploitation by removal of 50% …

Habitat Selection By Large Wild Ungulates And Some Aspects Of The Energy Flow In A Sub-Tropical African Savanna Woodland Ecosystem, Stanley M. Hirst

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A study of habitat selection by large wild ungulates was carried out on a 50 cm² area in the sub-tropical Lowveld region of eastern Transvaal province, South Africa. Estimations were made of herbaceous forage net productivity and ungulate secondary productivity on the same area.

Fourteen vegetation types, varying in composition and structure from open savanna to dense woodland, were delineated by association analysis. Structural and vegetational characteristics which were considered to influence ungulate distribution were measured within each vegetation type.

The study area supported resident populations of seven ungulate species during the wet season; drv season densities were higher …

The Relationship Of Climatic Factors To Grazing Activities Of Cows On Winter And Spring Ranges, Benton M. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this research was to investigate the effects of climatic variations upon the daily activities of grazing cattle. The activities of individual cows on a partially seeded salt desert shrub range were observed and recorded during three grazing periods. Two of the periods were during consecutive winters and the other during the spring. Climatic variations during the second winter period were quantified and compared to changes in the daily activity patterns of the cattle.

Distinctly different daily routines of cattle activities were evident for the winter and spring seasons. In the spring, the cattle grazed, traveled, and drank …

Trout Movements In A Small Mountain Stream, Thomas Mark Twedt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Five groups of 400 hatchery rainbow trout, (Salmo gairdneri), were stocked in a small, mountain stream at 3-week intervals from June to September, 1972. A fish trap captured any fish moving out of a 500 m study section.

Fish began moving at high levels during the first day of each stocking and continued at high rates for 5-8 days (Early Phase), after which movement decreased to low levels for 6-9 days (Late Phase). Early Phase fish moved primarily at night, possibly due to their disoriented state and high subjectivity to stream conditions. Fish moving during Late Phase did …

Effects Of Exercise On Serum Lactate Dehydrogenase Activity Of Catchable-Size Hatchery Rainbow Trout, Salmo Gairdneri, Gerlad T. Klar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Effects of exercise and the relative condition of exercised fish were viii evaluated for two strains of rainbow trout. Circular tanks fitted with a paddle were used to continuously exercise the fish and a stamina tunnel was used to evaluate the condition of exercised trout. Trout were exercised continuously at one fish-length per second and one-half fish length per second. Serum LDH activity in Shephard-of-the-Hills (Missouri) rainbow trout acclimated to 10 C increased two fold during the first four days of exercise. Serum LDH activity returned to control levels by the tenth day of exercise. Serum LDH activity in Shephard-of-the-Hills …

Growth Rate And Nesting Aspects For The Glossy Ibis In Virginia, 1972, John William Williams

Dissertations, Theses, and Masters Projects

No abstract provided.

Some Aspects Of Mercury Accumulation By The Purple Shore Crab Hemigrapsus Nudus Dana (Crustacea: Decapoda), Ralph Gene Swanson

University of the Pacific Theses and Dissertations

The present study has attempted to investigate some of the more basic questions concerning the toxicity and accumulation of mercury in the purple shore crab, Hemigrapsus nudus. This rocky intertidal denizen is found in abundance along the entire Pacific coast of the United States from Sitka, Alaska, to the Gulf of California where it dominates the mid-tide pool region. Local specimens were collected just north of the Pacific Marine Stations, Dillon Beach, Marin County, California. The animal is hearty and can be kept in a state of good health for long periods of time in the laboratory with minimum care …

A Numerical And Spatial Study Of The Meadow Vole, Microtus Pennsylvanicus, Margaret Whitney Higgins Bowker

Dissertations, Theses, and Masters Projects

No abstract provided.

A Study Of Organochlorine Insecticides In Freshwater Crayfish -- Analytical Problems And Biomonitoring Survey, Robert C. Vanderjack

Masters Theses

Crayfish were collected from 3 sites on Polecat Creek, Coles County, Illinois in early spring, early summer, and late summer of 1972. Pesticides were extracted from the crayfish tissue in a one step procedure utilizing a Florisil elution column. Analysis was by electron capture gas chromatography. Pesticide residues in the nannogram range were analyzed and background contamination was an important consideration. Sources of background contamination were investigated and teflon stopcocks, Florisil, and residues on “cleaned” glassware were found to be major contamination sources. Distilled water used in flushing glassware should also be considered a potential contamination source.

Aldrin, dieldrin, and …