Data from: Social costs enforce honesty of a dynamic signal of motivation

Understanding the processes that promote signal reliability may provide important insights into the evolution of diverse signaling strategies among species. The signals that animals use to communicate must comprise mechanisms that prohibit or punish dishonesty, and social costs of dishonesty have been demonstrated for several fixed morphological signals (e.g. color badges of birds and wasps). The costs maintaining the honesty of dynamic signals, which are more flexible and potentially cheatable, are unknown. Using an experimental manipulation of the dynamic visual signals used by male veiled chameleons (Chamaeleo calyptratus) during aggressive interactions, we tested the idea that the honesty of rapid color change signals is maintained by social costs. Our results reveal that social costs are an important mechanism maintaining the honesty of these dynamic color signals − 'dishonest' chameleons whose experimentally manipulated coloration was incongruent with their contest behavior received more physical aggression than 'honest' individuals. This is the first demonstration that the honesty of a dynamic signal of motivation − physiological color change − can be maintained by the social costliness of dishonesty. Behavioral responses of signal receivers, irrespective of any specific detection mechanisms, therefore prevent chameleon cheaters from prospering.

探究提升信号可靠性的内在机制，可为解析物种间多样化通信信号策略的演化历程提供关键洞见。动物用于通信的信号必然具备约束或惩罚欺骗行为的机制，此前已有研究证实，部分固定形态信号（如鸟类与胡蜂的色彩斑纹）的欺骗行为会带来社会成本。相较于固定形态信号，动态信号灵活性更强且存在被欺骗的潜在可能，目前学界对维持其诚实性所需付出的成本仍知之甚少。本研究针对雄性高冠变色龙（*Chamaeleo calyptratus*）在争斗互动中使用的动态视觉信号开展实验操控，以此验证快速变色信号的诚实性由社会成本维持这一假说。研究结果表明，社会成本是维持这类动态色彩信号诚实性的重要机制：实验中被操控体色、使其与争斗行为不符的“不诚实”变色龙，相较于“诚实”个体，遭受了更多的肢体攻击。本研究首次证实，作为动机动态信号的生理变色，其诚实性可通过欺骗行为带来的社会成本得以维持。由此可见，信号接收者的行为反应，无论其背后的具体识别机制为何，均能有效阻止变色龙作弊者获得演化优势。