Advertisement Calls of Two Horned Frogs, Megophrys kuatunensis and M. huangshanensis, from China (Anura, Megophryidae)

Animals communicating by sound face interference from biotic and abiotic sources. Contrasting strategies have been reported in different taxa in the presence of prolonged noise. Some torrent-living frogs of the genera Odorrana and Huia emit ultrasounds to avoid masking by environment noise. That strategy, however, might not be the only mode of acoustic communication for inhabiting along fast-flowing streams. To examine this possibility, we analyzed call structures of two horned toads, Megophrys kuatunensis and M. huangshanensis, which inhabit along streams in eastern China. We investigated variation in call properties within and between the two species and found that the two species show similar call structures but significantly differ in note duration and inter-note interval. Both of the two species concentrate energy on a single, wide harmonic band, and this might be an acoustic strategy against environmental noise.