Meeting Abstract
In brown anoles (Anolis sagrei), a lizard native to Cuba and The Bahamas, males defend small territories from other males. Males use a variety of agonistic behaviors, including dewlap flashes, head bobs, and push-ups, to secure and defend territories. In a previous study, we measured these behaviors in wild-caught adults from four Bahamian island populations and found that males from populations in Exuma and North Andros showed were significantly more aggressive than males from populations in Eleuthra and San Salvador. In order to determine whether these population differences were genetic or environmental, we reared offspring from two of these populations (Exuma and Eleuthera) in a common laboratory environment. Offspring were produced from both within- and between-population crosses. When male offspring reached at least 1 year of age, they were sorted into age-matched pairs from the same cross type and placed in a novel enclosure together for 30 min. Males could see each other, but were tethered to prevent physical contact with one another. Each male was tested twice. There was no significant effect of population of origin, suggesting that population differences may be environmental in origin. However, the behavior of opponents within a trial was significantly correlated, suggesting that a male’s immediate social environment may be the most important determinant of aggressive behavior. Future work will include more populations and will investigate aggressive behavior in unpaired lizards facing a standardized stimulus.
