Data from: Female anoles display less but attack more quickly than males in response to territorial intrusions

Fighting to defend a territory can be costly due to the risk of injury associated with physical combat. Therefore, many species rely on displays that allow individuals to assess one another, avoid escalation, and mitigate the costs of physical conflict. Most studies of territorial aggression have been conducted in the context of male–male competition, and although females of many species are also aggressive, direct comparisons of male–male and female–female aggression are rare. Consequently, the relative extent to which males and females of territorial species use behavioral displays and physical aggression to mediate intrasexual competition is generally unknown. To address this question, we experimentally introduced same-sex intruders onto the territories of male and female brown anole lizards (Anolis sagrei). We found that, although males were slightly more likely to attack an intruder than were females, males also allowed a greater amount of time to elapse before escalating to an attack, relative to females. Males also exhibited more aggressive display behaviors (dewlap extensions, push-ups, and head-bobs) before engaging in a physical attack. These results are consistent with the idea that, due to a potentially greater risk of injury, males may attempt to avoid escalating to physical conflict. The high rates of attack and low latency to attack that we observed for interactions between females also run counter to the general assumption that males are categorically more aggressive in territorial, polygynous species characterized by extreme male-biased sexual size dimorphism.为捍卫领地而发起的肢体战斗往往伴随受伤风险，因此代价高昂。为此，诸多物种演化出展示行为，使个体能够互相评估实力、避免冲突升级，并降低肢体冲突的代价。目前绝大多数关于领地攻击性的研究均聚焦于雄性间竞争场景，尽管诸多物种的雌性同样具备攻击性，但直接对比雄性间与雌性间攻击性的研究仍较为匮乏。因此，领地性物种的雌雄个体在介导种内竞争时，各自对行为展示与肢体攻击的依赖程度差异，目前仍未得到明确阐释。为解答这一问题，我们以雌雄棕安乐蜥（Anolis sagrei）为实验对象，将同性入侵者引入其领地范围内。实验结果显示，尽管雄性个体攻击入侵者的概率略高于雌性，但相较于雌性，雄性在升级为肢体攻击前的等待时长更长。此外，雄性在发起肢体攻击前，还会展现出更多攻击性展示行为，包括喉扇扩张、撑体动作与点头动作。上述结果与"由于雄性面临的受伤风险可能更高，因此它们会尽量避免冲突升级为肢体对抗"这一假说相符。我们观测到雌性间互动时的高攻击率与短攻击潜伏期，也与主流假设相悖——该假设认为，在以极端雄性偏向性性别体型二态性为特征的领地性一雄多雌制物种中，雄性的攻击性普遍更强。