The phrase “monkey see, monkey do” applies to humpback whales. Vervet monkeys and humpback whales both copy behaviors from their neighbors, researchers report April 25 in Science. The two studies suggest that, like humans, some wild animals pick up new habits from each other.
Accurately imitating one another’s actions is a “potential building block of culture,” says cultural evolutionist Peter Richerson of the University of California, Davis, who was not involved with the work. Complex culture builds upon people learning skills from each other, he says.
Scientists have previously spotted signs of social learning in monkeys, birds and other animals, but most studies relied on field observations or experiments with captive animals, says cognitive biologist Andrew Whiten of the University of St. Andrews in Scotland.
To gauge the role of social learning in wild animals, Whiten’s team trained four groups of vervet monkeys living in a South African game preserve to eat either blue or pink corn and despise corn of the other color. Whiten and colleagues did this by soaking one type of colored corn in an aloe solution that the monkeys found disgusting.
Then the researchers waited four to six months until the monkeys had given birth to a new generation. The team brought out both colors of corn again — but this time, none was tainted with the nasty flavor. Most of the adult monkeys stuck with the color they had learned was tasty, and all but one of the 27 infants munched on the color that their group preferred.
Since adult male vervet monkeys migrate among groups, the researchers could observe that nine out of 10 males that moved from pink to blue groups or vice versa swapped their color preference and ate what the locals were eating.
The migrants may have been tapping into local knowledge about food, Whiten says. Or the animals could have been trying to fit in with their new friends. “Trying to be like others is a way of bonding with another group,” he says.
Humpback whales learn from their buddies as well, reports marine biologist Luke Rendell, also from the University of St. Andrews – in this case, a feeding behavior. Humpbacks commonly blow bubbles underwater to round up prey, but in 1980, a single whale was seen adding a new twist to the old technique: Before casting a bubble net, the whale whacked its tail on the sea’s surface. The loud smack shakes up the water and may help the whale catch more prey. Since then, more and more whales have adopted the skill, called lobtail feeding.
The new results suggest the more time whales spend with members of their species who lobtail feed, the faster the whales learn the technique.
Rendell’s team drew on a gigantic collection of whale sightings in the Gulf of Maine, from a 27-year-long project. Whale watchers made more than 73,000 sightings, and logged date, identity, and behavior information (including hunting technique) about each humpback they spotted. The research team then used network analysis to draw connections between whales and their friends — a social network for humpbacks.
The more lobtail-hunting friends a whale had, Rendell says, the more likely the animal was to pick up the skill. The results suggest that humpback whales, which researchers have previously shown learn songs from one another, also pass on hunting behaviors.
“In this population, you’ve got multiple traditions going on,” Rendell says. He argues that this could constitute culture in the whales.
“Claims of tradition and culture in wild animals can be very contentious,” says evolutionary anthropologist Rachel Kendal of Durham University in England. Rendell’s group did a good job heading off potential criticisms, she says.
Still, Rendell says, “I’d love to be able to say that the case is closed, but I think there will always be debate about culture in animals.” And now, when people have that debate, he says, humpback whales will have to be part of it.