The researchers analyzed 64 vocal exchanges, called bouts, between at least two monkeys that were recorded between April and October 2012 at the Iwatayama Monkey Park in Kyoto, Japan. The team found that the median length of time between the end of one monkey’s calls and the beginning of another’s was 250 milliseconds — similar to the average 200 milliseconds in conversational pause time between humans. That makes the macaques’ gaps between turns in chattering one of the shortest call-and-response pauses yet measured in nonhuman primates.
The quick response time suggests the macaques are not calling out in habit, but are taking turns and coordinating their vocalizations, says Isaac David Schamberg, a primatologist at Harvard University who was not involved in the study.
“Monkey vocalizations are not static and automatic; they’re dynamic and conversational,” Schamberg says. [Continue reading…]