In chimpanzees, however, victims of aggression often produce
another type of call, ‘waa’ barks. Chimpanzee ‘waa’ barks belong to
an acoustic cluster of bark vocalizations that are given in several
contexts, such as hunting or when replying to long-distance calls
from other group members or from members of other communities
(Crockford & Boesch, 2003; Goodall, 1986; Marler & Tenaza, 1977).