Interpopulational Variation in Vocalizations of Bufo woodhousii

Abstract

Variation in dominant frequency, pulse rate, and duration of advertisement and release calls was investigated in populations of Bufo woodhousii australis and B. w. woodhousii. Temperature had a significant influence on all three advertisement call variables in both populations. The positive relationship between pulse rate and temperature was similar in both populations, as was the negative relationship between call duration and temperature. Although temperature-adjusted call durations were equal, adjusted pulse rates were slightly but significantly different between the two populations. When adjusted for body temperature, dominant frequency was the only call variable significantly (negatively) correlated with snout-vent length in either population. The two populations differed in adjusted dominant frequency but not in the negative relationship between frequency and snout-vent length. Analysis of temperature related variation in release calls was not possible, and the two populations differed signifi- cantly only in mean pulse rate. It is suggested that sympatric congeners may have influenced divergence in advertisement call frequency among subspecies of B. woodhousii.