What do frog calls tell us about males? The advertisement call of Physalaemus albifrons (Amphibia: Leptodactylidae) in the Brazilian semiarid region does not reflect either gonadal investment or energy storage

Abstract

ABSTRACT Anuran advertisement calls can provide accurate information on the reproductive quality of the male callers, thus providing females with indicators for the selection of mates. Body size is generally correlated with the dominant frequency of male advertisement calls. However, it is unclear whether and to what extent call parameters are associated with gonadal investment and the energy reserves of the males. Given that in tropical seasonally dry environments the wet season is very short, gathering information about gonadal investment and energy reserves of mates should be particularly important. In the present study, we evaluated the relationship between acoustic performance, gonadal condition, and fat storage in the Neotropical frog Physalaemus albifrons from the Brazilian semiarid region, testing the hypothesis that the advertisement call (repetition rate, call duration, and fundamental and dominant frequencies) would be a good predictor of male quality in terms of gonadal investment (testicle length) and energy reserves (mass of fat bodies). Contrary to our predictions, neither testicle length nor the mass of fat bodies was related to any of the acoustic parameters of the advertisement calls of P. albifrons. These results indicate that the advertisement call of P. albifrons does not provide reliable information on gonadal investment or energy storage of males. Possibly, in habitats with little and unpredictable rainfall, males of P. albifrons should present small variation in gonadal and fat storage conditions during its short reproductive window. Our findings contribute to the understanding of anuran reproductive strategies in seasonally dry environments.