Mating call differences between diploid and tetraploid green toads (Bufo viridis complex) in Middle Asia

Abstract

Mating calls of diploid and tetraploid green toads (Bufo viridis complex) from Iran, Turkmenistan, Uzbekistan and Kyrgyzstan were investigated during the breeding periods in 1994 and 1995 across a range of temperatures from 9°C to 22°C. Interpulse interval duration, pulse duration and call duration were negatively correlated with water temperature. At any given temperature tetraploid toads exhibited longer pulses and interpulse intervals resulting in lower pulse rates than diploid toads. These differences reveal a potential premating isolation barrier and provide an additional argument to consider diploid and tetraploid green toads as separate species. Call duration did not differ significantly between diploid and tetraploid green toads. Fundamental frequencies lay in the same range in both diploid and tetraploid toads.