FIGURE 15 in The use of bioacoustics in anuran taxonomy: theory, terminology, methods and recommendations for best practice

FIGURE 15. Spectrograms and oscillograms showing intra-specific call variation in two treefrog species from Madagascar, exemplifying the need to account for the possibility of different call / note types and of strong influence of motivation when taxonomically interpreting bioacoustical differences. (A) Males of Boophis at Antsatramidola, Madagascar, were emitting two very different types of calls, one of which might represent a territorial call. However, we never heard the two calls from the same individuals and therefore in the field were convinced of the presence of two morphologically cryptic species. Subsequent genetic study revealed that the individuals were all conspecific with B. tampoka and emitting two different call types (Köhler et al. 2007; Vences et al. 2011). (B) Boophis ankaratra emits long series of notes. Typical note repetition rate is reflected by the call from Manjakatompo, emitted by a male in the presence of several other calling males. At Itremo, during a dry evening, only few specimens were sporadically calling and obviously were in a state of low sexual motivation; despite a slightly higher temperature, note repetition rate was much lower at this occasion. Spectrograms produced with CoolEdit Pro at Hanning window function, 256 bands resolution.