Meeting Abstract
P2.13 Wednesday, Jan. 5 Condition-dependent mate choice in female gray treefrogs (Hyla versicolor) MURRAY, Erin M.*; HUMFELD, Sarah C.; Missouri State University; University of Missouri Erin1989@live.missouristate.edu
Females of many animal species can select a mate based solely on the characteristics of acoustic mating calls produced by males. Although previous research provides detailed descriptions of call preferences exhibited by female gray treefrogs (Hyla versicolor), variation in female mate choice is largely unexplained. In this study, I examined how total reproductive effort is allocated to egg production and mate-choice behaviors to determine whether condition contributes to variation among females in the form or strength of mating preferences. My study addressed whether mate choice is related to female 1) size; 2) condition; and 3) investment in eggs. Phonotactic preferences for longer call durations were tested using two experimental paradigms: in two-speaker playback tests, I recorded movement toward stimuli of differing amplitude to measure preference strength; in single-speaker playback tests, I recorded time required to move to the stimulus as a measure of responsiveness. After collecting behavioral data, I measured body size (SVL and TFL), mass before and after egg deposition, egg diameter, and number of eggs. I found that size, but not condition, significantly affected preference strength; larger females more strongly prefer the attractive longer-duration call. Energetic reserves not dedicated to egg-laying (residual condition) impacted response times to moderately loud (75 dB SPL) advertisement calls of various durations; females of higher condition respond faster to single-speaker stimuli. Females allocating more of their total body mass to egg production responded to average-duration calls in the single-speaker test more quickly than females laying fewer eggs. This condition-dependent variation in female mate choice likely contributes to the continuing variation in male advertisement calls over evolutionary time.
