When you hear the word “culture,” you might think more of the opera or the ballet than a whale whacking its tail on the surface of the ocean or monkeys that band together based on a liking for pink-dyed corn.
But a broader definition of culture includes simply any knowledge or experience transmitted through communication. And scientists are finding more evidence that certain animals exhibit behavior that meets that definition. In a pair of papers published in the journal Science on Friday, researchers found traces of what could be called cultural transmission in humpback whales and wild vervet monkeys.
"I've been arguing for over a decade now that cultural transmission is important in cetacean societies," Luke Rendell, the study's co-author and a University of St. Andrews marine biologist, told National Geographic.
Rendell and his team have followed the spread of a new kind of whale hunting technique called lobtail feeding that originated with a single individual off the coast of New England in 1980. The technique is a complement to an existing strategy called bubble-net feeding, where whales corral their prey by blowing bubbles around them, then surge through the ball of fish to gulp down a meal. Humpbacks that employ the lobtail feeding strategy smack their tails on the surface of the water before they blow bubbles, possibly to keep fish from jumping up away from the whale when it later surges upward.
The whale that first employed this technique did so at a time when herring populations crashed, leaving the whales more likely to feed on a fish called the sand lance.
In 27 years since the first whale started trying out the lobtail trick, 278 humpback whales have learned the strategy. Whale social networks seem to be a major factor in the spread of the behavior, the scientists found. A whale was more likely to pick up lobtail technique if they hung out with other whales that use the trick, suggesting there's some sort of knowledge transfer that can't be ascribed to genetics.
Is it social learning, culture, or just a matter of a bunch of whales learning to cope with a new kind of prey, independently? No one can quite say for sure.
In the other study published in Science, a team led by University of St. Andrews primate researcher, Erica van de Waal, divided vervet monkeys in the wild into two teams: “pink” and “blue.” Some monkeys were trained to prefer eating corn that was dyed in their team color and were also coached to dislike the opposing color. Then, they looked to see how new arrivals to the groups – both adult males on the move and newly born monkeys – reacted to the color-coded norms.
Baby monkeys followed their mothers' examples when selecting which color corn to eat. Most of the adult males tended to adhere to the local culture as well. The only male that didn't stick with the right color was one that soon became the big honcho of his group – possibly indicating that even among monkeys, those on the top don't have to worry about what everyone else is doing.
“The take-home message is that social learning — learning from others rather than through individual trial and error — is a more potent force in shaping wild animals’ behavior than has been recognized so far,” coauthor, Andrew Whiten, told Scientific American.
SOURCES: Allen et al. “Network-Based Diffusion Analysis Reveals Cultural Transmission of Lobtail Feeding in Humpback Whales.” Science 340: 485-488; van de Waal et al. “Potent Social Learning and Conformity Shape a Wild Primate's Foraging Decisions.” Science 340:483-485, 26 April 2013.