Image: Gabriel Barathieu

When American and British whaling ships hunted for sperm whales in the North Pacific in the early 1800s, they noted something disturbing. After initially good results, the whalers’ success in harpooning the whales fell by about 58% over the first few years of whaling. Now, a study led by Hal Whitehead, a whale biologist at Dalhousie University in Nova Scotia, may have found the answer as to why this happened. Using data from digitized whaleship logbooks, his team determined that the most likely explanation is that the sperm whales learned how to avoid the whalers and taught other groups of whales how to do the same.

Sperm whales are intelligent with the largest brain of any animal. They are also a highly socially evolved species, with strong familial bonds. When the whalers first arrived the only predator encountered by sperm whales were orcas. The sperm whale formed defensive circles which were effective in countering orcas but made them easy prey for the whalers.

The research suggests that over about a two and a half year period, the whales learned to swim into the wind or to dive deep to avoid the whalers in open boats. The analysis suggests that the spread of these techniques across widely dispersed groups of whales reflects “rapid social learning on a large scale” made possible, in part, by the use of long-range echolocation and directionally focused clicks to communicate over several kilometers. 

Sperm whale study reveals survival lessons within species

Thanks to Alaric Bond for contributing to this post.