Date of Award
College of Arts and Sciences
Master of Science
Signals are morphological or behavioral traits that an individual uses to influence the behavior or actions of another. These signals can be used in male-male competition, in which male secondary sexual traits act as a signal of his fighting ability. Animal signals are considered honest when the signal reliably indicates a specific trait or condition of the individual. The genus Anolis, comprised of over 400 species that occupy the tropics and the southeastern United States, utilize aggressive signaling prior to physical combat. Research on several tropical species of anole indicates that the size of their dewlap can act as an honest signal of their fighting ability, as dewlap size is correlated with the chance of an individual winning in combat. No studies of this nature, however, have been done for the green anole, Anolis carolinensis. In this study, I measured the size of adult male green anole’s dewlaps, their bite forces, and performed dyadic interactions between two males matched for body size to determine if the dewlap can be considered an honest signal of fighting ability. I found that dewlap size, mean bite force, and maximum bite force did not differ between winners and losers of dyadic interactions. However, latency to bite did differ between winners and losers, and there was a predictive relationship between dewlap size and latency to bite. These results could be explained by the different personalities of male green anoles, specifically regarding an individual’s level of boldness. Being bold in a high-risk situation, such as in male-male competition, is dangerous for an individual and comes with the chance of injury or death. The dewlap of the male green anole could potentially act as an honest signal of his cautiousness, and his hesitancy to engage in male-male competition, but also his confidence in his capacity to defeat his opponent if the conflict reaches the actual combat stage.
Hughes, Alexia, "Is the Dewlap an Honest Signal of Fighting Ability in the Male Green Anole (Anolis Carolinensis)?" (2021). Graduate Theses. 131.