title: A special constraint on the evolution of composite signals.
abstract: Many animals use composite signals, combining e. g. auditory and visual components. If the components travel at different speeds, the time lag between reception of the components increases with increasing distance from the sender. Problems arising especially from rhythmical repetition of composite signals are discussed and possible solutions are indicated.
mesh_terms: D000819:Animal Communication; D000818:Animals; D001717:Birds / Q000502:physiology; D005260:Female; D008297:Male; D010507:Periodicity; D014828:Vocalization, Animal / Q000502:physiology