Alexander Sweet, “Where Did She Go? : Changes in Social Context Alter Calling Strategies of Eastern Gray Treefrogs”
Mentor: Gerlinde Höbel, Biological Sciences
Oral Presentation 9am Union E240

How a species reacts to a change in social context can be critical in understanding its overall behavior, especially during courtship displays. In lekking species this is of utmost importance as behavioral adjustments in response to social context can have great ramifications on an individual’s mating success. Here, we explore how male Eastern Gray Treefrogs (Hyla versicolor) change their calling strategies in response to a change in social context. Male Eastern Gray Treefrogs emit advertisement calls consisting of a series of short pulses (ranging from 5-30), and those displaying more pulses (longer duration call) or a faster call rate are considerably more attractive to females. However, males have finite energy and are limited to one high energy call trait (duration or rate). We recorded individual males across two social contexts and take into consideration environmental change. We first recorded lone, naturally displaying males in the pond, then united each male with a female to form a mating pair (amplexus) for an hour, then recorded the males again in response to amplexus interruption. We also accounted for changing environmental factors such as temperature throughout this process. The results show that male frogs before amplexus invest energy into emitting longer duration calls, but after amplexus separation invest energy into a faster call rate instead. Even though the call strategies shift from prioritizing longer to faster, they maintain similar energy outputs (i.e. no change in duty cycle). We also found a significant effect of male ID, indicating a unique individual element to calling behavior despite the significant change in strategy. Temperature also had a significant effect on male calling, but not in a manner that compromised the significance of social context.