Overlapping And Synchronization In The Song Of The Indris (Indri indri)

In Indri indri, males and females within a social group emit loud, long distance calls in a coordinated manner. An indri may start emitting a vocal utterance before the end of another individual’s contribution, resulting in different degrees of overlap between individual songs. This study provides the first quantitative analysis of the individual overlap between indri males and females showing the adult pair members mainly overlap each other. The adult female song also has an effect on male singing in 35% of the cases, while the timing of a song unit could predict the occurrence of a unit sung by another group-member in only 10% of the other dyads (e.g. male-female or male-youngster).