The absence of species and sex recognition during mate search by male common toads, Bufo bufo

Abstract

During mate search male Bufo bufo do not discriminate between green frogs and conspecifics, between sexes or between gravid females that differ in body size. We studied mate recognition and the mating behaviour of male European common toads, B. bufo using field-based choice experiments. When given a simultaneous choice between R. perezi and B. bufo both matched in size, male toads did not dis- criminate between species and amplected a frog or a toad with equal frequency. When a male toad amplected a frog, the frog uttered a release call but the toad did not release the frog and the amplexus lasted from several seconds to a few minutes. Usually frogs fought to release the male toad but test toads were tenacious and usually attempted several times to clasp the frog when the frog slipped away from toad. When given a simultaneous choice between a male and a female of equal size, males did not discriminate between the sexes and attempted to amplex a male or a female with equal frequency. When a test male clasped a stimulus male, the stimu- lus male uttered a specific release call that caused the test male to release the stim- ulus male. Male-male amplexus never lasted more than 3 sec, and consequently, the search cost associated with mating with the wrong sex was relatively low. Males did not discriminate between gravid females that differed in body size. Moreover, there was no assortative mating by size. Male-female amplexus was tenacious and prolonged in the three experiments