As well as the sponging technique, a new technique for drinking was observed at Bossou, whereby the chimpanzees would fold a leaf in their mouth and placed it into the water hole using it as a receptacle. This behavior differs from that observed at other chimpanzee field sites, where chimpanzees only use leaves as a leaf sponge for drinking water. The outdoor laboratory was also recently set up to observe this behavior in more details.

The chimpanzees of Bossou also use leaves as a sponge or as a recipient for drinking water (Sugiyama, 1995; Tonooka et al, 1994; Tonooka, 2001).

leaves folded by chimpanzees