Female choice and selection on male calling behaviour in the grey treefrog Hyla versicolor

Abstract

Variation in male calling behaviour and female choice was investigated in a population of the grey treefrog, Hyla versicolor, with a lek mating system in east-central Maine over 3 years. Operational sex ratios were male-biased and males obtained zero to four matings within a breeding season. In laboratory discrimination experiments in which all other acoustic parameters were held constant, females preferred long-duration calls over short, and calls broadcast at high rats. Males exhibited consistency in calling behaviour: repeatabilities (intra-class correlation coefficient) ranged from 0·14 to 0·65 for duration, pulse rate and dominant frequency of advertisement calls, and call rate. Selection differentials and standardized selection gradients did not reveal any consistent relationships between male calling behaviour and mating success. The only variable influencing male mating success was the number of nights of participation in chorus activity.