Aspects of the Social Structure of the California Ground Squirrel (Spermophilus Beecheyi) in Western Oregon PDF Download

Author: Carol E. Bickford
Publisher:
ISBN:
Category : Squirrels
Languages : en
Pages : 112

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Book Description
A population of Spermophilus beecheyi was studied to determine patterns of individual spacing, behavioral interactions among different sex and age classes, and the relationship between aspects of S. beecheyi social structure and sociality to those of other sciurids. Research was conducted on a population of squirrels living in an abandoned rock quarry on Finley National Wildlife Refuge near Corvallis, Oregon. Squirrels were trapped, marked with dye, and observed during March through October, 1977, and March, 1978. The location of each squirrel and the type and location of any encounters were recorded during 325 hours of observation. The types of encounters most often observed were approach/ withdrawal, greeting/investigation, play, displacement, aggression, and the male-initiated paw push. The two major activity peaks occurred in March, corresponding to courtship activity and male defense of breeding territories, and in July, corresponding to the activity of juveniles. The seasonal activity cycle of S. beecheyi had five phases: breeding, pre-emergence of young, litter, pre-hibernation, and hibernation. distinct time of dispersal was determined. The population consisted of approximately twice as many adult females as adult males. Both sexes had overlapping home ranges, but their centers of activity were usually separate from the activity centers of other members of the same sex. Home ranges were retained from year to year by the same squirrel. The most social sciurids are those which exhibit a high frequency of cohesive behaviors, such as greeting and mutual grooming. The S. beecheyi at Finley National Wildlife Refuge tended to be tolerant of other individuals, but did not maintain a high level of cohesive behavior within the population. The social structure of S. beecheyi was intermediate to the more social S. columbianus and the more solitary S. franklinii.