Context-specificity of the different calls produced by the three habituated males in response to natural events.

B = boom, K+ = krak-oo; K = krak, H+ = hok-oo, H = hok, W+ = wak-oo. N = number of events; In each cell: mean (± standard deviation) number of calls recorded per event; 1mostly flying squirrels; 2mostly Diana monkeys, C. diana; 3mostly fleeing duikers (Cephalophus spp.); 4mostly male loud calls; 5Call exchanges by females and juveniles, usually in response to neighbouring male; 6Male usually out of visual contact with group.