Sexual selection in Woodhouse's toad (Bufo woodhousei). II. Female choice

I studied female choice in a prolonged-breeding population of Bufo woodhousei australis in central Arizona during the spring of 1981 and 1982. Field observations revealed that variation in call rate was significantly greater between males than within males and that male call rate was correlated with mating success. Male size was not significantly correlated with mating success, or did I observe positive assortative mating with respect to body size. Females did not discriminate between calls of large and small males in choice experiments. However, males with high call rates were preferred, independent of size. For anurans, these results are the first to document clearly female choice based on male phenotype independent of male size. It is suggested that high call rate may be an indicator of male fitness in this female-choice system.