The Sonoran Desert Toad
The release call:
Males of the genus Bufo and of other anuran genera produce a distinct acousticomechanical signal that is known as the release call, or warning vibration. This signal is a sex identification mechanism that ensures rapid release when one male is clasped by another (Aronson 1944). Rapid releases are presumably advantageous since energy is conserved, gamete wastage is prevented, and the amount of time that the sexually preoccupied males are exposed to predation is reduced (W.F. Blair 1968).