Date of Award


Degree Name

Master of Arts


Biological Sciences

First Advisor

Dr. Thane S. Robinson

Second Advisor

Dr. Leo C. VanderBeek

Third Advisor

Dr. William C. Van Deventer

Access Setting

Masters Thesis-Open Access


The fox squirrel, Sciurus niger rufiventer, is an important small game animal throughout much of the Midwest. Within the last thirty years several scientific investigations have been focused on this animal, the result being that its life history and ecology are fairly well known.

Concerning the range of the fox squirrel, D. L. Allen (1943:33) states that, in Michigan, the range began to increase with the advent of the pioneers. Baumgartner (1940) and J. M. Allen (1952) noted similar occurrences in their respective states, Ohio and Indiana. In Kansas, the fox squirrel, aided by agricultural land-use, has spread westward throughout nearly the entire state (Packard, 1956:61). Hoover and Yeager (1953) indicated that the fox squirrel had increased its range in Colorado. See Fig. 1, for the geographic distribution of Sciurus niger rufiventer in the United States.

Except where it occurred in the few prairie island remnants and oak-openings in the southwest corner of Michigan, the fox squirrel was non-existent in the state before the coming of the pioneers (D. L. Allen, 1943:31). These individuals, farmers and lumbermen, found the southern part of the state covered with a dense hardwood forest. North of a line drawn across the state westward from the Southern most point of Saginaw Bay, the hardwood forest graded into a transition zone of mixed hardwoods and conifers. This dense, mature forest cover constituted an ideal habitat for the gray squirrel Sciurus carolinensis and the black squirrel, a melanistic variation of the gray squirrel. In the process of lumbering or clearing the land of farming, the pioneer began to change and destroy the environment of the gray squirrel and unknowingly created habitat suitable for the fox squirrel. As a consequence of the fox squirrel has spread throughout the lower peninsula of Michigan.

The microclimatological factors which influence the daily activity of the fox squirrel need further study. Hicks (1949) and Packard (1956) both investigated various factors of the environment affecting squirrel activity, however they made no attempt to gather data in the immediate vicinity (microclimate) of the squirrel itself.

The purpose of this investigation was to determine the effect of certain factors of the microclimate (temperature, relative humidity, light intensity and wind velocity) on the activity of a population of fox squirrels. The behavior of individuals in this population was observed as a consequence of studying their activity. Special attention was given to activity possibly associated with territoriality.

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Biology Commons