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.