Date of Graduation

Summer 2014


Master of Science in Biology



Committee Chair

Alicia Mathis


Communication of information concerning the sender's quality or intentions is essential for maintaining territories, courtship, and mating. For signals to be favored by natural selection, they must benefit both the sender and the receiver. A dishonest signal that provides misleading information about quality or intent should therefore be selected against. Honest signals prevent cheating because they are constrained by factors such as the energetic costs of the signal. I tested the hypothesis that "All Trunk Raised” (ATR), a behavior that occurs in territorial contests in terrestrial salamanders, is an honest indicator of aggressive intent. In staged contests between pairs of Ozark zigzag salamanders (Plethodon angusticlavius), individuals that performed bites spent more time exhibiting ATR prior to biting than individuals that did not bite. In addition, I examined whether ATR is an energetically costly behavior. In trials where the diet of the intruder was manipulated, high-quality intruders tended to perform more ATR than low-quality intruders. In metabolic rate trials, individuals that performed more ATR produced more CO2. These results support the hypothesis that ATR is an honest indicator of aggressive intent in this species.


honest signals, diet, behavior, metabolism, carbon dioxide production, aggression, Plethodon

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