Reproductive Ecology of the Peruvian Earless Toad Rhinella yunga (Amphibia, Bufonidae) with Descriptions of Calls, Tadpole, and Female Competition

Abstract

Rhinella yunga is a poorly studied but locally abundant endemic bufonid toad found only in two habitat islands of the buffer zones surrounding the Yanachaga-Chemillen National Park and the Pui Pui Protected Forest in the Selva Central, Peru. Rhinella yunga is unique because it lacks a complete tympanic ear and is larger than most toads lacking a tympanic ear. Here, we report on the natural history, reproductive behavior, and territorial and release calls of R. yunga following field- and captivity-based observations across two breeding seasons. We also provide a description of tadpole external morphology based on a developmental series of laboratory-reared larvae. We found that R. yunga (1) uses low frequency calls (800–1,100 Hz) that are likely detectable without tympanic middle ears and (2) appears to exhibit an unusual mating system with female competition at breeding ponds prior to male arrival. Under these conditions, the need to hear male advertisement calls might have become unnecessary in this species.