Male-male vocal interactions in a territorial neotropical quail: which song characteristics predict a territorial male's response?

Males singing within their territories can change their song characteristics in order to interact with conspecifics; males may respond to territorial intrusions by vocalizing, approaching the intruder and/or displaying. I studied male-male interactions by quantifying vocal and behavioural responses of male spot-bellied bobwhites (Colinus leucopogon) toward playback of conspecific male songs. Male responses toward playback song depended on the quality of the territorial male's song relative to the playback stimulus. In this species males who sang songs with higher peak and low frequency, longer song duration, and lower song rate were less responsive to simulated territorial intrusions. Spot-bellied bobwhite males that sang in response to the playback increased the low frequencies of their songs relative to pre-playback song, a vocal behaviour related to dominance in males of other species. Males that approached the speaker sang longer songs, a characteristic associated with increased aggression or motivation to fight in other bird species. The results of this playback experiment suggest that male spot-bellied bobwhite song characteristics according to playback characteristics predict response to territorial intrusions and may, therefore, play an important role in male-male interactions. [ABSTRACT FROM AUTHOR]