Meeting Abstract

P1.5  Tuesday, Jan. 4  Food Supply Affects Territory Size, but not Social Display Behavior in Green Anole Lizards (Anolis carolinensis) LEWIS, C.M.*; BATTLES, A.C.; SPARKS, M.N.; JOHNSON, M.A.; Trinity University, San Antonio clewis@trinity.edu

Food availability can have a strong influence on the social interactions of territorial animals, particularly when food is a defended resource. Territorial, insectivorous lizards such as those in the genus Anolis provide an excellent opportunity to determine how food influences territory dynamics. A field experiment by Guyer (Ecology, 1989, 69:362-369) showed that supplementing the food supply of anoles resulted in increased male growth, female egg production, and territory overlap (but no change in territory size). However, no studies using natural (unmanipulated) variation in food supply have yet examined the effects of food supply on anole territory dynamics and social display behavior. In this study, we examined green anole lizards (Anolis carolinensis) in three habitats: an open field, a maintained trail, and a palmetto forest in Palmetto State Park in Gonzales, Texas. We quantified insect abundance, biomass, and diversity in these habitats using trapping and transect methods, and we observed anoles (n=90) to determine rates of display behaviors (pushups and extensions of the throat fan, or dewlap) and territory sizes. Results showed that insect availability differed among the habitats, but rates of male or female display behaviors did not, suggesting an absence of behavioral response to changing food supply for either sex. However, lizards in the habitat with the lowest insect abundance had the smallest average territory size for both females and males, yet this habitat also had the most available biomass of the orders of insects most commonly eaten by lizards. This suggests that while insect availability affects lizard territory size, the available biomass of preferred insects has a stronger effect on territory size than their abundance.