Master's Theses

Date of Award

Summer 1959

Degree Name

Master of Science (MS)

Department

Biology

Advisor

Committee Chair

Abstract

An investigation was made to determine the role of pelage color of Peromyscus maniculatus nebrascensis in relation to the type of soil and the vegetation the Nebraska deermouse inhabits. P.m. nebrascensis displays several different shades of pelage coloration which may afford protection from predation. Also, the pelage color of a particular species or subspecies, distinguished mainly by differences in pelage color, tends to be correlated with the color of the soils of their habitats. Two methods of securing specimens were employed. Snap trapping was done with Museum Special traps to secure specimens in various soil and vegetation types. Eight trap sites were sampled in the western one-third of Kansas, generally a mixed prairie habitat. The trap areas were selected in relation to the type of soil and vegetation. The composition of the soil was described from Soil Conservation Service maps of the various areas. The vegetative composition of the areas was ascertained by estimating the frequency and abundance of forbs and grasses present. Each animal collected was weighed, measured, sexed, and the pelage color described. Three skins, from a collection representative of western Kansas, were selected as type colors. The lightest was marked number one, the darkest number three and the intermediate was marked number two. Specimens taken were given a number between one minus and three plus by visual comparison with the selected series. Live traps were used to secure specimens for the breeding study. A breeding program was organized to determine how pelage color of parents was transmitted to the offspring. The number of breedings completed was limited by available time; and no useful data was obtained. Data were also used from established trap line located in the college relict area. Animals caught were recorded in relation to color and released. Seventy-eight P. maniculatus were caught in a seven month period, with the same individual being captured more than once in some instances. Data gathered from the investigation may be found in Tables I through V. The characteristics of P. m. nebrascensis as well as other subspecies of Peromyscus, have a genetic basis, as shown by lack of modifiability even when the habitat is changed. The comparative frequencies of the Mendelian genes for pelage color should afford some measure of the intensity of selection against Peromyscus that are conspicuous on their backgrounds. Natural selection by predators is an important factor in the evolution of pelage color in Peromyscus. The pelage color of Peromyscus maniculatus nebrascensis in western Kansas showed no significant relationship between pelage color and the type of vegetation in which the trapped specimens lived. The distribution of pelage color did not differ from the distribution of total population in the three vegetative types. The pelage color of P. m. nebrascensis showed a direct relationship to soil color only in the light colored soil. There was only a slight tendency toward a relationship between pelage color and the medium to dark soils. In further investigations of pelage color of P. m. nebrascensis, the author would suggest that a more detailed and extensive study would yield valuable information.

Rights

Copyright 1959 John M. Nickel

Comments

Notice: This material may be protected by copyright law (Title 17 U.S. Code).

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