Meeting Abstract

45.2  Jan. 6  Geographic variation in the advertisement call of Hyla arenicolor GERHARDT, H. C.; HUMFELD, S. C.*; MARSHALL, V. T.; University of Missouri-Columbia; University of Missouri-Columbia; University of Illinois humfelds@missouri.edu

The canyon treefrog, Hyla arenicolor, is a cryptically colored treefrog that inhabits rocky canyons throughout the southwestern United States and Mexico. Although populations occur in a fairly wide variety of habitats (seasonal watersheds in the xeric Sonoran and Chihuahuan Deserts to permanent streams in the relatively mesic Colorado Plateau), regions containing these sources of water are often separated by vast areas of arid country. One consequence of the low gene flow between such isolated populations is large interpopulational genetic differences (with sequence divergences as high as 13.7%). Phylogenetic analysis has revealed three deeply divergent mtDNA lineages that inhabit nonoverlapping geographical regions. To test whether the communication system of this species has changed in concordance with genetic changes, we recorded advertisement calls produced by 155 male H. arenicolor from several populations in each of the three clades. We analyzed the calls in terms of spectral content (low and high frequency spectral peaks, relative amplitude), gross temporal properties (call duration, call rate, number of pulses, pulse repetition rate) and fine temporal properties (pulse duration, pulse rise and fall times, number of subpulses). The magnitude of interpopulational variation in call characteristics does not match genetic variation, and here we suggest some testable explanations for this discrepancy