Neighbor–stranger discrimination by song in male blue grouse

Playback experiments demonstrated that male blue grouse tan distinguish the songs (hoots) of neighbors in the correct direction from those of other male blue grouse. Specific responses to playbacks of song differed among individuals, but each bird responded more strongly to songs of strangers than to those of neighbors. Responses to stranger playbacks were higher while responses to neighbor playbacks were lower using stranger–neighbor–stranger sequences as compared with neighbor–stranger–neighbor sequences.