dc.description.abstract | Recent studies in animal behavior have demonstrated that behaviors are often repeatable. Variation in behaviors arise at many levels, including the level of a single individual, and between individuals in a population. Characterizing these differences in behavior among and within individuals can provide information about the repeatability of the behavior; how consistent the behavior is over multiple measurements of the same individuals. In this study, I examined how call characteristics of the American toad (Anaxyrus americanus) vary both within an individual and among individuals in a population. More specifically, I measured five call characteristics (dominant frequency, call duration, pulse rate, pulse number, and call rise time) and examined how they varied across various environmental and social factors. I then estimated repeatability for these call characteristics, through = repeated sampling periods of the same individuals. Overall, call characteristics were affected by multiple environmental variables. In addition, the number of males present in a breeding chorus affected the variation in calls: with more males present in a chorus, larger males had lower dominant frequencies. Both dominant frequency and call duration were significantly repeatable, indicating that individuals are consistent in their display of these two call characteristics. My results demonstrate that individuals differ in their display of reproductive behaviors over multiple environmental factors. Competition among males might be occurring via overlap of calls Repeatable call traits (dominant frequency and call duration) are assumed to be characteristics determined by individual factors such as size, age, metabolism, parasite load, etc. Furthermore, these consistent individual differences shown through high repeatability may indicate the potential for these mating behaviors to respond to selection. | |