Male Position Relative to Foam Nests Influences Female Mate Choice in the Túngara Frog, Physalaemus pustulosus

Abstract

Vocalizations are critical advertisement signals used during anuran courtship. In most species, acoustic signals have primacy, but visual cues also have been shown to play an important role in anuran mate attraction. Male Túngara Frogs, Physalaemus pustulosus, produce advertisement calls, and males that are successful in attracting a mate build conspicuous white foam nests in which fertilized eggs are deposited. Foam nests persist for several days and on subsequent nights, male frogs are often observed calling adjacent to these foam nests. We tested the hypothesis that females approach the vocalization of a male adjacent to a foam nest preferentially. We conducted choice tests allowing females to choose between two speakers broadcasting a male vocalization—one speaker adjacent to a foam nest and the other speaker lacking a foam nest. Females expressed a significant preference for a speaker with a foam nest when the nest was visible. These results indicate that males may increase their probability of attracting a mate when calling adjacent to a foam nest relative to males located farther from a foam nest.