Anuran males often call in groups. Those of the toad Bufo regularis mutually adjust their calling rhythms. In the frog Kassina senegalensis they suit the rhythm of one particular male, making him a call-leader.

Literature
Wickler, Wolfgang & Seibt, Uta 1974: Rufen und Antworten bei Kassina senegalensis, Bufo regularis und anderen Anuren. Zeitschrift für Tierpsychologie 34, 524-537