Thesis (Ph. D.)--University of Wisconsin--Madison, 1953. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [71-74]).

Thesis (M.S.)--University of Wisconsin--Madison, 1963. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Dispersal of cotton rats was examined over an annual cycle of abundance by removal trapping in pine flatwoods. All cotton rats live-trapped at biweekly intervals on two 0.49 ha grids were removed, whereas rats on an adjacent control grid were tagged an released alive on site. The null hypothesis was that dispersing cotton rats would represent a random sample of sex and weight (age) classes from source populations, e.g. the control grid. Likewise, it was assumed that dispersal rates would be proportional to numerical changes in abundance on the control grid. Dispersing animals were clearly most prevalent on the removal grids during November and December 1979 when numbers of rats on the control grid were increasing. Breeding ceased in December and fewer animals dispersed between January and May. The cumulative number of individual animals captured or removed from the study grids (control and removals) was remarkably similar. The proportion of individuals removed according to weight class was not significantly different among grids. Sex ratios of rats on the control and removal grids were not different from 50:50 (P > 0.05). The conclusion is that dispersing cotton rats represented a cross-section of age groups and sexes. The results support the rank-order template hypothesis as the dispersal strategy of the cotton rat. Genetic and behavioral differences between dispersers and source populations could not be discriminated with the methodology employed.

Cotton rats, Sigmodon hispidus, were trapped and studied in Belize District, Belize, Central America from June 14, 1973 to July 13, 1973. Vegetation in the area was surveyed to determine height, extent of matting, and species composition. Comparisons were then made between vegetation and S. hispidus captures. A total of 48 S. hispidus,were captured, primarily in areas of tall and matted grass. S. hispidus appeared to be absent from areas of short grass.Reproduction, body size, sex ratio, parasites, and behavior of S. hispidus are discussed. Other mammals taken during the study included two specimens of Or_yzomys, fulvescens,, a species which had not previously been collected in Belize.Ball State UniversityMuncie, IN 47306

Thesis (M.S.)--Georgia Southern University, 2009. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science." Directed by Lance A. Durden. ETD. Includes bibliographical references (p. 17-32) and appendices.

This investigation has been concerned with determining the extent to which a small mammal, the cotton rat, may become acclimated to environmental temperatures, and the influence acclimation has upon a population. The study was also designed to determine if acclimation effects on a population can be seen in individual rats.

The Mississippi Alluvial Valley (MAV) has undergone losses of bottomland hardwood forests due to agricultural conversion. Hardwood establishment on marginal croplands has been proposed to mitigate effects of deforestation and related loss of carbon-capture potential. However, a possible concern with reforestation is low seedling survival from mammalian herbivory. I surveyed two afforested fields in the MAV of northwest Mississippi to assess damage and mortality from four herbivores on nine species of hardwood seedlings (n = 868). Percentage survival of seedlings was 35%. Mortality of seedlings caused by herbivores was: hispid cotton rat (Sigmodon hispidus; 6.45%), rabbit ((Sylvilagus spp.; 1.95%), pine vole (Microtus pinetorum; 2.99%), and white-tailed deer (Odocoileus virginiana; 0.69%). Of surviving seedlings (n = 316), 10.82% were damaged by cotton rats, pine vole (2.99%), rabbit (8.06%), and deer (7.02%). Green ash (Fraxinus pennsylvanica), water oak (Quercus nigra), and Nuttall oak (Quercus nuttallii) had greatest survival.

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