Bonobos apparently search for a lost member injured by a snare

Nahoko Tokuyama, Besao Emikey, Batuafe Bafike, Batuafe Isolumbo, Bahanande Iyokango, Mbangi N. Mulavwa, Takeshi Furuichi

This is the first report to demonstrate that a large mixed-sex party of bonobos travelled a long distance to return to the location of a snare apparently to search for a member that had been caught in it. An adult male was caught in a metallic snare in a swamp forest at Wamba, Luo Scientific Reserve, Democratic Republic of the Congo. After he escaped from the snare by breaking a sapling to which the snare was attached, other members of his party assisted him by unfastening the snare from lianas in which it was caught and licked his wound and tried to remove the snare from his fingers. In the late afternoon, they left him in the place where he was stuck in the liana and travelled to the dry forest where they usually spend the night. The next morning, they travelled back 1.8 km to revisit the location of the injured male. When they confirmed that he was no longer there, they returned to the dry forest to forage. This was unlike the usual ranging patterns of the party, suggesting that the bonobos travelled with the specific intention of searching for this injured individual who had been left behind. The incident described in this report likely occurred because bonobos usually range in a large mixed-sex party and try to maintain group cohesion as much as possible.