VOCAL REPERTOIRE OF THE LONG-TAILED MANAKIN AND ITS RELATION TO MALE-MALE COOPERATION

We examined the vocal repertoire oflek-mating Long-tailed Manakins (Ch iroxiphia linearis, Pipridae) in Monteverde, Costa Rica. Males in this genus are unusual in performing a cooperative courtship display, incl uding duet songs and coordinated dual-male dance displays. Males give at least 13 distinct vocalizations, several of which occur in clear be havioral contexts. By observing the behavioral context and the sequenc e in which calls were given, we found that the most frequent calls occ urred during three types of activity: song bouts, dance, and noncourts hip interactions. The responses of males to playback of six vocalizati ons indicated that the calls function as much in mediating cooperative interactions as in expressing male-male agonism. The evolution of the large vocal repertoire in Long-tailed Manakins may be associated with their unique social system based on longterm, cooperative relationshi ps among males.