Not All Signals are Equal: Male Brown Anole Lizards (Anolis sagrei) Selectively Decrease Pushup Frequency Following a Simulated Predatory Attack


Valerie B. Simon, P. O. Box 701135, Wabasso FL 32970, USA.


The use of conspicuous communication signals often increases a signaler's risk of predation. Many species communicate with a repertoire of signals that may differ in their conspicuousness to predators. Few studies have examined the ability of prey to selectively decrease the use of individual signals in their displays under heightened predation risk. Here, I examined the behavior of male brown anole lizards (Anolis sagrei) in response to a simulated predatory attack from a model kestrel. This species communicates with three major visual signal types, the head-bob, pushup, and dewlap extension, which vary in their motion and spectral characteristics. I predicted that lizards would decrease frequencies of the dewlap extension and pushup following the attack, but not the head-bob. Males modulated their use of individual signals by decreasing pushup rates, but not head-bob rates. Decreases in dewlap frequency were marginally significant. One explanation for these results is that lizards decrease frequencies of signal types based partly on their conspicuousness. The energetic cost of each signal type may be an equally important factor that determines the signaler's response to predators, particularly if a predatory attack is perceived as imminent.