FBTs have at least 4 distinct calls: normal mating call, the modified mating call, the clasping call and the release calls. The mating calls change when the toads grow. Larger animals have a lower fundamental frequency and a longer duration of calls than smaller ones.

Obviously, there are slight differences in calling frequency and pattern among the various species in the genus Bombina (FBT). For example the European FBT (Bombina bombina) has 5 calls, while Bombina variegata (yellow-bellied toad) has only 4 calls.