Friends react faster when a friend calls for help than when a stranger calls, according to study results released July 31. Makes sense, except that the subjects in the study weren’t human. They were crested black macaques (Macaca nigra). Dr. Antje Engelhard, working from an Indonesian field station near Mt. Tangkoko, tested the reaction of group members to alarm calls that macaques make when they see a python. (Pythons are one type of snake that eats macaques.) The alarm call of a macaque attracts other macaques to help drive away the predator. Analysis of video-recordings made by the researchers showed that friend macaques react faster than stranger macaques. Englehard concludes that social bonds are more important than kinship in cooperative defense against predators.
Here’s what you need to know: Male crested macaques weigh about 22 lbs., about twice as much as the average female, according to the Primate Information Center at the University of Wisconsin, Madison. In Tangkoko, on the island of Sulawesi, these primates travel in groups “varying from 27 to 97 individuals.” These macaques mainly eat fruit, but they also consume seeds and leaves, flowers, and pith (center portion) of many stems, as well as fungi, bird eggs, birds, lizards, and frogs.
- German Primate Center (2012, July 31). Friends help more promptly, at least in monkeys. ScienceDaily. Retrieved August 1, 2012.
- Cawthon Lang KA. 2006 February 2. Primate Factsheets: Crested black macaque (Macaca nigra) Taxonomy, Morphology, & Ecology<http://pin.primate.wisc.edu/factsheets/entry/crested_black_macaque>. Accessed 2012 August 1.