Meeting Abstract

P2.1  Monday, Jan. 5  Temperature-dependent preferences for advertisement-call frequency in females of Hyla versicolor GRUNERT, B; HUMFELD, S*; GERHARDT, C; University of Missouri; University of Missouri; University of Missouri bkgbn8@mizzou.edu

Global climate change has the potential to impact many components of biological systems, including the behavior of various animal species. Ectothermic animals face an interesting communication challenge, in that ambient environmental temperatures can significantly impact characteristics of the species-specific advertisement call. Male treefrogs produce loud and persistent acoustic signals called advertisement calls to attract mates. The mate-choice preferences of female gray treefrogs (Hyla versicolor) have been extensively studied, and it has been found that females tested at 20 C prefer calls with standard bimodal frequency peaks of 1.1 + 2.2 kHz over calls with higher and lower frequencies. However, we do not know how this preference might be affected by temperature. To determine whether acoustic preferences based on frequency are temperature-dependent, I collected female frogs during their breeding season and tested their preferences in a temperature-controlled anechoic testing chamber. I generated ten different computer-synthesized advertisement calls that ranged in frequency between 0.55 + 1.1 kHz and 1.5 + 3.0 kHz. In two-speaker choice tests conducted at three different temperatures (15 C, 20 C and 25 C), I observed the choice (moved within 10 cm of a speaker) females made between a call with standard frequency peaks of 1.1 + 2.2 kHz and one of the nine alternative calls. Preliminary results indicate the preferred frequencies appeared to remain at 1.1 + 2.2 kHz at lower temperatures. However, at higher temperatures, female frogs were more likely to approach high-frequency calls. These results will be discussed in the context of well-known temperature-dependent physiological processes in the inner ear of frogs.