Mathematical Analysis of Social Dominance in the Green Anole Lizard


Meeting Abstract

P3.19  Monday, Jan. 6 15:30  Mathematical Analysis of Social Dominance in the Green Anole Lizard BUSH, J. M.*; QUINN, M. M.; JOHNSON, M. A.; BALREIRA, E. C.; Trinity University jbush1@trinity.edu

Dominance relationships are an important aspect of the social organization of many species, and male dominance often results in successful territory defense and/or access to potential mates. In this study, we identified the behavioral and morphological traits associated with dominance in green anole lizards (Anolis carolinensis). We first performed a tournament of arena trials using pairs of 18 male lizards. These arena trials stimulated aggressive interactions, often resulting in a clearly dominant male. We used these data to rank the lizards using a series of algorithms, including original ranking methods developed specifically for this application. Our results showed that behavioral displays and relative head length (but not body size) were the most predictive of rank in the majority of ranking systems. We then sought to validate our results by comparing male rank to territory size, a proposed proxy of social dominance. In two replicate studies with 10 male lizards each, we first used a series of arena trials to determine individuals’ ranks. We then placed the 10 males in an enclosure with 10 females and measured the sizes of male territories over one week. Although we hypothesized that higher ranked males would have larger territories, we found no correlation between rank and territory size. Finally, we measured morphological traits, aggressive behavior, and territory size in 24 green anoles in Palmetto State Park, Gonzales, Texas, to determine how these traits were related in a natural population. Results from this study indicated that body size (but not behavior) was an important predictor of territory size. Thus, the traits associated with successful long-term defense of a large territory in green anoles may be independent from those needed to win short-term confrontations.

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