New ways to grab dinner, the trick to using a tool, and
learning the local dialect. These are behaviors that animals pick up from each
other. Killer whales, chimpanzees, and birds seem to have a cultural component
to their lives. Now a new study suggests that sperm whales should be added to
that list.
The ocean around the Galápagos Islands hosts thousands of
female sperm whales and their calves that have organized into clans with their
own dialects. (Mature males congregate in colder waters near the poles.) How
these clans form has been something of a mystery until now.
A study published recently in the journal ‘Nature
Communications’ suggests that culture—behaviors shared by group members—keeps
these sperm whale clans together. Specifically, these deep-diving whales have a
distinct series of clicks called codas they use to communicate during social
interactions.
Sperm whales with similar behaviors spend time together, and
they pick up vocalizations from each other. Scientists call this social
learning. Whales that "speak the same language" stick together,
giving rise to the clans that researchers have observed for more than 30 years.
This is one more pillar of support for the idea that animals
have culture, says lead study author Mauricio Cantor, a marine biologist at
Dalhousie University in Halifax, Canada.
When Cantor and colleagues ran computer simulations to
determine the most likely way the clans formed, factors like genetic
relatedness or the transmission of information from mother to offspring
couldn't explain the pattern observed in the wild. The best explanation their
analysis could find was a preference in how sperm whales learned vocalizations.
"Like-minded" individuals learned from each other.
It's fascinating to see that animals like whales display
something that may seem uniquely human, Cantor says. But really, "we're
not that different from them."
Killer whale pods have their own dialects, humpback whales
pass on new feeding behaviors via their social networks, and chimpanzees share
the secrets of tool use with their compatriots.
(Adapted from National
Geographic magazine 2015)