Intraspecific Variation in Home-Range Size in Some Anolis Lizards

Abstract

Intraspecific variation in home-range area is investigated using observations on 896 individuals in four Anolis species distributed over 16 sites in the Bahamas. A. sagrei, a highly terri- torial, polygynous species, typically has smaller home ranges than the three more arboreal species; areas are as small or smaller than recorded for any other lizard. Adult males have larger home ranges than adult females. Adult male home-range area, relative to that of females, in all species but distichus, is over twice as great as expected from relative energetic requirements. Subadult-male ranges are especially variable, possibly indicating variation from a territorial to a wide-ranging, nonterritorial strategy. In sagrei, but not the other species, home-range area increases more strongly with body size in males than females; one female sagrei regression is significantly negative. Regressions of two other species frequently have negative slopes. The rate of increase in home-range area with body size for sagrei males, but not the other species, is similar to the rate for interspecific lizard regressions. Variation about the regression line in most cases is high. Within a sex and site, home-range area is unrelated to relative growth rate or to survival. In the largest sagrei data sets, the number of adult females within an adult male's home range is significantly related to both the male's home-range area and his body size. Home-range area in classes of sagrei is inversely related to density of the same and other classes; in adult females and subadult males the relation is strongest using density of all conspecifics; in adult males it is strongest using adult male density. In two other species, the relation frequently is not inverse, especially in subadults.