Khao Yai white-handed gibbons present during the study period.
: individual males for which only descriptive analysis is available (seeTable 4);**
: H. pileatus female coupled with a lar male for several years;°
: animals excluded from analysis (N = 3) because of missing samples;‡
: animals excluded from analysis (N = 3) because no male solo songs were recorded (only duets were available).
Only adult males were considered in the analysis.