Geographic Variation in Calls of Males and Determination of Species Boundaries in Tetraploid Frogs of the Australian Genus Neobatrachus (Myobatrachidae)

Abstract

I analysed geographic variation in advertisement call of tetraploid forms of Neobatrachus. Comparing five regional samples spanning the range of N. kunapalari, there was significant geographic variation in pulses per call but not in dominant frequency, pulse rate, pulse duration or percentage rise time. The call of N. kunapalari was significantly different from four other samples covering the geographic range of tetraploid forms across Australia in all but percentage rise time. Calls of frogs from Mt Magnet in Western Australia (WA) differed from calls from Port Hedland (WA) in pulse duration and in multivariate descriptions but were similar in pulse rate. Pulse rates of calls from N. centralis on Eyre Peninsula in South Australia (SA) were distinct from all other populations sampled but in multivariate space these calls were similar to calls of N. sudellifrom eastern Australia. There may be an eastwest cline in call from N. sudelli to calls of N. aquilonius and N. centralis in WA. Call data support the recognition of two tetraploid species: N. kunapalari and N. sudelli. N. sudelli exhibits geographic variation in call, but the status of N. aquilonius and N. centralis as possible synonyms of N. sudelli was not resolved.