The Dynamics Of Space Use In A Red Squirrel (tamiasciurus Hudsonicus) Population (indiana).

The purpose of this study was to investigate how red squirrel (Tamiasciurus hudsonicus) spatial activity and social behavior responds seasonally to the need for resources, especially those required for reproduction. Real, predictable trends were evident, indicating that selective pressures have encouraged behaviorial plasticity. Squirrels were equipped with radiocollars and followed from January 1983 to September 1984 in a mixed conifer-hardwood forest in northern Indiana, USA. It was hypothesized that because of changing requirements for critical resources, the spatial extent of activity in male versus female squirrels would differ during the periods here classified as mate-search, mating, gestation, lactation, and nonbreeding. Results indicated that males moved farthest during the mate-search (Mean home range size from two year's data: males = 0.93 ha, females = 0.18 ha), mating (males = 2.67 ha, females = 0.51 ha), and gestation (males = 1.05 ha, females = 0.41 ha) periods. Females moved farthest during the lactation periods (males = 0.27 ha, females = 0.54 ha). Home range size was equal between the sexes for the nonbreeding periods (males = 0.07 ha, females = 0.07 ha). During these periods, mortality was highest for the sex moving the farthest (mate-search, males = 3 deaths, females = 0; mating, males = 4, females = 0; gestation, males = 2, females = 0; lactation, males = 0, females = 8; nonbreeding, males = 0, females = 0). For males, mates probably represented a critical resource, whereas for females the critical resource was food during lactation. The rate of rattle calling increased during the times when the young were dispersing and during the mating periods. Calling was infrequent and home ranges most stable in the nonbreeding periods when animals remained near their caches. Juveniles displayed three categories of philopatry: (1) ranges of parent and offspring overlapped extensively or were congruent; (2) offspring took over part of the parental home range and lived on the periphery of the parent's area; or (3) parents dispersed and relinquished the home range to the offspring.Ph.D.Biological SciencesEcologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/128043/2/8712240.pd