Life Sciences Commons^™

Demographic Analysis And Microhabitat Relationships Of A Small Mammal Community In Clearings Of The Great Dismal Swamp, Jean Ferguson Stankavich

Biological Sciences Theses & Dissertations

Small mammals were trapped for 14 months on two grids located within a powerline right-of-way in the Great Dismal Swamp National Wildlife Refuge. During 12,354 trap nights, individuals of 10 different species were captured. They included, from highest to lowest density, Reithrodontomys humulis, Ochrotomys nuttalli, Peromyscus leucopus, Blarina brevicauda, Synaptomys cooperi, Microtus pennsylvanicus, Microtus pinetorum, Sigmodon hispidus, Mus musculus and Oryzomys palustris. The demography (densities, reproduction, home range and dispersal) of each species was analyzed when possible. Most of the species were present in relatively low densities, with a number being captured only during the latter months of the study. …

Life History Aspects Of Reithrodontomys Humulis In Southeastern Virginia, Michelle Cawthorn Chandler

Biological Sciences Theses & Dissertations

Reithrodontomys humulis, the eastern harvest mouse, is a small cricetid rodent which is common in old field communities in the eastern U.S. A live-trapping study was conducted in Suffolk, Virginia from March 1983 through February 1984 in order to learn the details of its life history and the vegetational characteristics which best describe its microhabitat. Specifically, population densities, trap-revealed survival times, home ranges, plant species composition of the study area, and vegetational structure were examined. In order to trap as many Reithrodontomys as possible, special traps which excluded animals weighing over 20 g were constructed. Densities of harvest mice …

Activity Levels Of Arboreal Rodents Peromysus And Ochrotomys Evaluated With Nest Cans In Seasonally Flooded Forests, John W. Walke

Biological Sciences Theses & Dissertations

The diversity and density of small mammals in the Dismal Swamp are believed to be small. To test this, four 1.96 ha grids were established and operated in the Dismal Swamp National Wildlife Refuge, from September 1981 to November 1982. Number 10 metal cans covered with plastic lids were placed as nest boxes at 0.5 to 1.5 m height on trees. A 2.5 cm hole allowed access by arboreal rodents, to each nest can. The activity level of the two arboreal rodents, Peromyscus leucopus and Ochrotomys nuttalli, was evaluated by observing types of activity ranging from presence of mice to …

On The Anatomy And Phylogeny Of The Zoarcidae (Teleostei: Perciformes), M. Eric. Anderson

Dissertations, Theses, and Masters Projects

The eelpouts, Zoarcidae, are a group of bony fishes, most species of which inhabit continental shelves and slopes of boreal seas. There are about 200 species of eelpouts, most of which are rare in collections, thus they have been only cursorially studied by most workers. as a result, the systematics of the family is in a poor state. This work is a contribution to the improvement of that state. The anatomy of all nominal genera of Zoarcidae was studied in an attempt to reconstruct phylogeny and establish the limits of genera. From analysis of a matrix of 63 characters, the …

Anatomical Observations On The Ampullae Of Lorenzini From Selected Skates And Galeoid Sharks Of The Western North, William Raschi

Dissertations, Theses, and Masters Projects

The gross structure of the ampullae of Lorenzini and its distribution on the body of 40 species of skates (Rajoidei) and 5 species of sharks (Galeomorphii) were compared in an attempt to investigate correlations within this system to feeding mechanisms. Three general lines of morphological change are observed. A larger proportion of the ampullary pores are associated with the ventral surface of the dorsoventrally flattened skates than the more conically shaped sharks. The relative proportion of ventral pores is significantly reduced on those species inhabiting aphotic waters. Secondly, the more piscivorous rajoids possess an array of ventral pores which covers …

Feeding Strategies And Functional Morphology Of Demersal Deep-Sea Ophidiid Fishes, H. Jacque. Carter

Dissertations, Theses, and Masters Projects

The hypothesis is advanced that ophidiid fishes prevalent beneath oligotrophic tropical seas have evolved trophic specializations appropriate for existence in regions of low primary productivity where ultimate energy available for food production in benthic communities is low. The feeding strategies of these tropical dwelling deep-sea fishes are discussed within the context of this hypothesis. The feeding strategies of tropical dwelling deep-sea ophidiid fishes are examined through an analysis of food habits and examination of morphological features related to feeding. Three main modes of feeding are evident among these fishes: (1) predation upon small benthopelagic or planktonic organisms by small-bodied species …

The Distribution And Abundance Of The Bottlenose Dolphin, Tursiops Truncatus In Virginia, Robert A. Blaylock

Dissertations, Theses, and Masters Projects

No abstract provided.

Aspects Of Breeding Behavior Of The Royal Tern (Sterna Maxima) With Particular Emphasis On Prey Size Selectivity, William James Ihle

Dissertations, Theses, and Masters Projects

No abstract provided.

Observations On Relationships Between Limb Measurements And Mode Of Locomotion In Malaysian Turtles, Duayne Nyckel

Masters Theses

Twelve Genera (spanning three Families) of Malaysian Turtles were studied to determine whether bone lengths could be correlated to mode of locomotion. Ulna, humerus, tibia, femur, coracoid (among others) were measured and results were presented graphically. Five of the genera were observed singly in a large aquarium. Data were recorded on the amount of time each spent in different locomotor modes. Both limb length data and aquarium observations suggest that turtles can be grouped into three main locomotor habits (i.e. terrestrial walking, bottomwalking, and swimming). The terrestrial group includes the genera, Geochelone, Kinixys, and Gopherus. Bottomwalkers include …

Use Of Skelettochronology In Age Determination Of American Toads (Bufo Americanus) From East Central Illinois, Philip M. Acker

Masters Theses

A skelettochronological technique was applied to the phalanges of the American toad, Bufo americanus, from east central, IL. In hematoxylin-stained cross-sections of the phalanges, suspected year rings are formed which can be used to age individuals. This method allows for aging without destructive sampling of toad populations.

A majority of the male toads from two choruses were estimated to be 2 or 3 years old, while most of the females from the same two sites were in the 3 or 4 year age class. Females were larger than males in the 3 and 4 year age classes, and overall, …

Operant Conditioning In The Water Snake (Nerodia Sipedon), Angela R. Deitz

Masters Theses

Six subjects of Nerodia sipedon were tested for runway acquisition. Five of six subjects met criterion for runway learning, demonstrating a significant decrease over the 25 day testing period in mean latency and running times. Four subjects completed 170 trials in a T-maze to test two-choice discrimination and reversal learning. All subjects met criterion for the initial discrimination and one reversal while two subjects completed four reversals and one subject met criterion for six reversals. Results are similar or superior to those previously reported for reptiles and other non-human vertebrates.

Avoidance Learning And Memory In Largemouth Bass (Micropterus Salmoides) Fed Bufo Tadpoles, Randy John Gawlik

Masters Theses

Tadpoles of the American toad (Bufo americanus) have been shown to be distasteful to largemouth bass (Micropterus salmoides) predators who learn, on the short term, to avoid them. How long bass retain this learned avoidance of Bufo larvae is unknown so an experimental design was constructed in an attempt to answer this question.

Largemouth bass were divided into four treatment groups. Two groups were initially fed exclusively larvae of Bufo americanus (one group was fed large tadpoles, the other group fed small larvae). Similarily, the other two groups were initially fed spring peeper (Hyla crucifer …