THE EFFECTS OF CONTEXT, SEX, AND BODY SIZE ON STAGED SOCIAL INTERACTIONS IN JUVENILE MALE AND FEMALE GREEN ANOLES (ANOLIS CAROLINENSIS)

We documented the ontogeny of headbobbing display use in green anoles (Anolis carolinensis) by determining the effects of social context, sex, and body size on juvenile social interactions. Juveniles only gave displays in social interactions (never while isolated), and activity levels in general were much higher during interactions than during isolation. Neither social context (consexual or heterosexual) nor sex affected the type or quantity of displays and related behaviors (perch shifts, display modifiers, color changes, and approaches or retreats). Interactions always appeared to be aggressive in nature and qualitatively similar to interactions between adult females. Both males and females tended to increase overall activity during interactions with body size, including the use of displays and related behaviors, and large juvenile males performed more headbobbing displays than did large juvenile females. These results suggest that juvenile social interactions are agonistic in nature and that they function to defend both immediate and future resources (prospective resource hypothesis). It is likely that resource protection confers the immediate benefits of suitable habitat for foraging, thermoregulation, and predator avoidance, and it is hypothesized that the primary future benefit is the acquisition of the eventual breeding territory that juveniles will hold as adults.