Meeting Abstract

86.3  Sunday, Jan. 6  Rescuing of call attractiveness using novel acoustic appendages in gray treefrogs, Hyla versicolor HENDERSON, J.J.*; GERHARDT, H.C.; University of Missouri, Columbia; University of Missouri, Columbia jhenderson@mail.missouri.edu

Acoustic signals vary from simple, repeated elements to a combination of diverse elements that create a complex signal. Complex calls are found in a variety of taxa, from the multi-note calls of songbirds to the syntax of human speech; however, call complexity is relatively rare in the widely studied anuran amphibians. To study questions regarding complex call evolution, it is critical to understand the mechanisms of the sensory system and its inherent biases in order to establish “rules” affecting the attractiveness of novel complex signals. The gray treefrog (Hyla versicolor) serves as a powerful model system for examining the rules that determine the effectiveness of novel complex signals. One such rule, temporal order, is an important factor in novel call attractiveness as females often preferred complex calls consisting of the pulsed advertisement call of the species followed by a novel acoustic appendage. This observation may be explained by a class of interval-counting neurons that are selective for interpulse interval. These neurons fire after a number of intervals with correct duration. The most selective of these neurons can be reset after one incorrect interval. The results of this study show that calls with one or more inappropriate intervals or pulses with short duration are discriminated against when presented with normal advertisement calls. In addition of a novel acoustic appendage often “rescued” call attractiveness for these inappropriate calls. These results suggest that the interval-counting neurons do affect call attractiveness and that appendages may lessen discrimination of an unattractive call.