Advertisement Call Variability in the Black-spined Toad Bufo melanostictus (Anura: Bufonidae) during the Breeding Season in Lishui, Zhejiang, China

Advertisement calls play an important role in influencing female mate choice and are regarded as one of the key characters responsible for reproductive isolation and speciation events in frogs and toads. The black-spined toad, Bufo melanostictus, is one of the most common amphibians in Southeast Asia and is frequently observed in human habitations throughout its distributional range. The advertisement calls of the toad have not been well described. Here, we report the advertisement calls of this species from Lishui, Zhejiang, China during its breeding season. The advertisement calls of B. melanostictus are composed of single notes with a single harmonic frequency emitted sporadically. The call parameters recorded in this study were highly variable across recording times and with different body sizes. Dominant frequency was negatively correlated with body size. Comparing the calls of the B. melanostictus population from Lishui with the populations from five other localities (Bangkok, Thailand; Coorg, India; Burma, Myanmar; Bali, Indonesia; Halimun-Salak National Park, Indonesia), we found that call structure was similar among five different populations with no harmonics, while the Halimun-Salak National Park population contained two clear harmonics. Dominant frequency was similar between Bali (1.56 kHz) and Coorg (1.6 kHz) populations, while it was highly variable among other populations. Besides call duration, call interval and pulse/call rate may also be significantly different among the comparing populations. Pooling the available data, we observed some similarities and differences in call parameters among the six populations.