February 7, 2017 by Bob Yirka
(Phys.org)—A team of researchers with members from Canada, Japan and the U.S. has found that social skills in capuchin monkey mothers plays a role in the survivability of her offspring. In their paper published in Proceedings of the National Academy of Sciences, the researchers describe their study of the monkeys in their native Costa Rica and behavioral traits they observed that might be translatable to humans.
To learn more about capuchin behavior, the research team studied data collected over the years 2005 and 2011 by researchers studying the monkeys in their native Costa Rica. They found that adult females that are more sociable tended to have babies with higher survival rates than less social mothers during times of stability. But, they also found that the situation was reversed when the dominant male in the group was either threatened or replaced—offspring of more social mothers were more likely to become the victims of infanticide by the new leader. Interestingly, they also found that maternal sociability came out even in the end—the team found no evidence of differences in offspring survivability rates overall.
Capuchin monkeys are well known throughout the world as both companions (or organ-grinders) and care-givers for humans. Their small size and childlike demeanor are considered assets and because of that, they have often been used in television and movies. In the wild, they are very different, of course—they inhabit areas from as far north as Central America to as far south as Argentina. Their behavior in groups as large as 35 has been extensively studied due to their social nature, which in some ways mimics that seen in humans.
In this latest study, the researchers suggest sociability plays a factor in offspring survivability because of the physical location they both occupy within the group—generally in the social nucleus. During times of stability, living in the middle of the group can provide protection for offspring from predators. Unfortunately, it can also make them the first to be targeted when a new lead male is looking to mate with those females closest in proximity. It is thought that new males kill infants to relieve the mothers from responsibility for them, making them available for mating.