For bonobos, all sex sounds the same
Bonobos, great apes renowned for their sexual promiscuity, copulate for a variety of reasons—to procreate, to strengthen social bonds, to ease tension, and to settle spats between group members. So one would expect that a bonobo engaged in sex might produce a different vocalization for each different social context in which the act was occurring. Not so, according to researchers studying the species' copulation calls in the wild. The scientists recorded calls from 4 adult female bonobos in the Democratic Republic of Congo and found that their acoustic structure did not change whether they were mating with a male or another female. This is surprising because other primates that engage in reproductive and non-reproductive sex typically make distinct ...