When orcas are two-legged…

Two sperm whales at Surface. NW Mediterranean. 2020. © Carla A. Chicote/SUBMON

In the middle of the 19th century, whaling captains moved their ships towards the North Pacific where they began to hunt sperm whales. These large cetaceans, with big brains, very well adapted to the marine and with complex social structures faced a new predator appearing almost out of nowhere. Large sailing whaleships arrived at the whaling ground and deployed an army rowing whale open-boats that approached and harpooned them to death. If whales were killed they would be brought to the whaleship for processing: meat, bones … and most important, oil. 

Whaleship captains had a very exhaustive control over the daily navigation and capture activity, which they wrote down in their logbooks. The study of the information collected in these logbooks at present digitized and accessible, is proving to be a very valuable source of information for researchers to better understand how this large-scale commercial exploitation put in the verge of extinction many species of large cetaceans. This information it is also useful to improve knowledge on the biology and behavior of these animals …. and has also served to answer one of the big questions … if these sperm whales were so smart (they have the largest brain on the planet), why did they stay as if nothing waiting to be killed? The answer is simple: They did not. 

The spermaceti whale. The Natural History of the ordinary Cetacea or Whales. 1843. Autor: Sir William Jardine

In mid-March 2021 a study was published where after analyzing 77,749 whaling operations from logbooks it was found that the effectiveness of striking (harpooning) sperm whales, once sighted, was reduced by 58% in just 2.4 years … what was going on? The models applied in the study suggest that sperm whales learned from this new threat, information about what was happening to them was shared collectively among sperm whale groups and allowed them to make vital changes in their behavior to avoid the new threat. Among these changes there are accounts from the whalers themselves writing on defensive methods that sperm whales adopted: communicating danger within the social group, attacking both whaleships and open-boats (Melville and his Ahab were right) and also fleeing  upwind making it difficult for both sailing and rowing boats to reach the optimal position… they managed to reduce the action of these new two-legged “orcas” as far as they could … Until when?  Until Mr. Svend Foyn in 1870 invented the harpoon gun, a lethal accessory mounted on the bows of the also new steamboats … which maneuvered as far as and how they wanted … but that is another story.

“A Harpooned Whale” original J.M.W Turner 1845. © Manel Gazo