A Canadian researcher says new findings into sperm whale escape tactics are providing insight into why the marine mammals are not extinct.
Hal Whitehead, biology professor at Dalhousie University, worked with colleagues from the United States and the United Kingdom. They studied newly digitized whaling logbooks from the North Pacific Ocean, concluding sperm whales made smart use of their remarkable asset: the biggest brain on earth.
The peer-reviewed research paper was published this week, in the Royal Society research journal.
“We have a real habit of underestimating what other animals can do,” said Whitehead, a long-time sperm whale researcher who lives along the south coast of Nova Scotia, near Halifax.
Traditionally, sperm whales’ only predator was the orca. Staying safe meant forming defensive circles and smashing their tails outwards.
But that tactic left them wide open to be slaughtered when whalers began hunting them in the 18th and 19th centuries.
Whitehead says the new findings bolster a theory that the whales adjusted by leaving their formations and swimming upwind to escape from the whalers, who were also powered by the wind.
“So the whalers saw a sperm whale and they went after it. But their success in killing it went down by about 60 per cent in three to five years.”
Whitehead says the whales can communicate over great distances, using sonar clicks, with each family group using a different dialect.
He says it’s possible they warned each other in the same way they share information about where to find food.
“And they used this information to, at least some of the time, more and more often as time went on, behave in a way to evade the whalers.”
The findings could raise hope for the endangered North Atlantic right whale. Their numbers are dwindling, because of ship strikes and fishing gear entanglement, in Atlantic Canada.
“That does give us a bit of hope that they can learn effective methods to avoid the noise, the fishing gear, the plastic.”
Whitehead suggests that creatures that survived for millions of years before humans existed should not be underestimated.