Behaviour 2019
Individual Variation in Multivariate Signal Assessment in Female Gray Treefrogs
Kane Stratman, Gerlinde Hoebel. UW-Milwaukee, Milwaukee, WI, United States

Female choice is a well researched topic of sexual selection. Biologists have described both the variation in male displays and shape of female preferences across many taxa. In the wild, choosers assess displays that vary for multiple traits, but much of what is known about preference stems from responses to univariate scenarios. We tested preference expression by gray treefrogs in a two-choice scenario with bivariate call manipulation. The rate and duration of males’ calls are inversely proportional, generating an abundance of “mixed attractiveness” among neighboring calls (e.g. males with a comparatively shorter but faster call). We used this trade-off in a design that forces females to prioritize one trait over the other, finding that duty cycle is widely required for discrimination. Among those that did demonstrate repeatable preference, there was support for prioritization of call duration. These females chose a stimulus significantly faster than inconsistent females, indicating “confused” sampling behavior among less discriminant females. These findings provide insights on the cognition of multivariate assessment and the efficacy of female choice in evolution.