Dawn and Dusk “Chorus” in Visually Communicating Jamaican Anole Lizards

A key hypothesis explaining the existence of dawn and dusk choruses in acoustically communicating animals centers on the need to advertise continued territorial occupancy after and before a period of nocturnal inactivity. If this hypothesis is correct, it follows that similar dawn and dusk choruses should occur in territorial animals exploiting other signal modalities. Adult male Anolis lizards defend territories by using elaborate head-bobbing displays and extensions of a throat fan or dewlap. Males are inactive at night and return to their territories at dawn, remaining there until dusk. I quantified the production of visual displays as a function of time of day for four species on the island of Jamaica: Anolis lineatopus, Anolis sagrei, Anolis grahami, and Anolis opalinus. All exhibited dawn and/or dusk peaks in display behavior. These patterns have remarkable parallels with the dawn and dusk choruses reported for many acoustically communicating animals.