DEMONSTRATION OF LINE TRANSECT METHODOLOGIES TO ESTIMATE URBAN GRAY SQUIRREL DENSITY

Because studies estimating density of gray squirrels (Sciurus caroline nsis) have been laser intensive and costly, I demonstrate the use of l ine transect surveys to estimate gray squirrel density and determine t he costs of conducting surveys to achieve precise estimates. Density e stimates are based on four transects that were surveyed five times fro m 30 June to 9 July 1994. Using the program DISTANCE, I estimated ther e were 4.7 (95% CI = 1.86-11.92) gray squirrels/ha on the Clemson Univ ersity cam pus. Eleven additional surveys would have decreased the per cent coefficient oi variation from 30% to 20% and would have cost appr oximately $114. Estimating urban gray squirrel density using line tran sect surveys is cost effective and can provide unbiased estimates of d ensity, provided that none of the assumptions of distance sampling the ory are violated.