Pinoy scientist helps uncover sperm whales' complex language and social structure

Researchers from Dalhousie University, University of Colorado at Boulder, University of the Philippines, University of California-Santa Barbara, Georgia Institute of Technology, and the University of Notre Dame have found evidence that sperm whales use culture to maintain separate social groups even while sharing the same waters, just like humans do. The research was published in the journal Nature Communications.

Filipino pride
 

Reniel Cabral, a Filipino who is one the study's coauthors and a recent PhD graduate of the National Institute of Physics in UP Diliman, says that "I am proud that a Philippine institution is included in a paper published in one of the world's top [academic] journals. I hope that the Philippines will continue fostering international collaboration by supporting the research of students and academic institutions."

Clan 'codas'
 

Sperm whales (Physeter macrocephalus) form hierarchal social groups like those found in humans, non-human primates, and African elephants. The smallest social group is a unit composed of about 12 members that share the same maternal line, with several units joining together to form a clan. Each clan has a distinctive set of "codas", or the click patterns sperm whales use to communicate with each other. Previous studies have shown that each whale only groups with other whales that share its codas. Considering that each ocean houses several sperm whale clans that could potentially mix together, how do these clans maintain their groupings over time?

 

The researchers used 18 years worth of tracking data from sperm whale clans in the Eastern Pacific Ocean. Individual whales were identified using the marking on their tails, while clans were determined based on how similar their codas were. Using the data to produce agent-based models, the researchers tested whether sperm whale groupings in the wild could be explained by calves coming up with their own codas (individual learning), calves learning codas from their mothers (genetic inheritance), or calves copying codas from random adults (pure social learning).

Cultural heritage among whales
 

Their results showed that genetic inheritance or pure social learning could not explain sperm whale groupings. Rather, they found that biased social learning through a combination of calves copying adults who sounded similar to them (homophilly) and calves copying the most common coda types (conformism) best explained the groupings. In short, whale clans stick together through the passing down of culture, or socially learned behaviors shared within the group.

 

Said Mauricio Cantor, lead author of the study, "Our findings show that social learning among sperm whales is the required ingredient for the segregation of clans with different 'dialects'. This gives us evidence that key features of human culture—which we think makes us so different from everything else in nature—might be at play in populations of other animals." — TJD, GMA News
 

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Macy Añonuevo, a noted photographer, travel writer, and biologist, earned her MS Marine Science degree from the University of the Philippines. Her writings and photographs may be found at www.theislandergirl.com.