Research Training Program

Leo Gueriguian
University of Wisconsin - Madison
Madison, Wisconsin

Richard W. Thorington, Jr., Ph.D.
Project Advisor
Department of Vertebrate Zoology
Division of Mammals

"The RTP provided invaluable experience which has been most useful in my research."

Body Size Variation in Ground Squirrels (subgenus Spermophilus) in Relation to Habitat Aridity

Body size in mammals may be affected by many different factors, one of which may be aridity. The objective of this study was to test if a correlation exists between body size and habitat aridity in ground squirrels (subgenus Spermophilus). Condylobasal skull length was used as an indicator of body size. Aridity was quantified using the Budyko-ratio of aridity index. Felsenstein's (1985) independent contrasts method and a standard Pearson's product-moment correlation analysis were performed to find any correlation between the two traits. These analyses rendered significant correlation (P < .005) ranging from +0.597 to +0.783. Aridity accounts for 35-61% of body size variation in these ground squirrels.

This research was supported by a grant from the Smithsonian Women's Committee.