Humpback Whales Make and Use Tools for Hunting, Study Discoveries

It is not uncommon for non-human animals to use tools. New research suggests that humpback whales engage in an even rarer behavior: creation hunting tools. The paper, published in Royal Society Open Sciencedocuments how whales blow bubbles to create nets to trap krill.

To be considered tool use, animals must use something not attached to their body to manipulate their environment. Animals from chimpanzees and elephants to fish and insects are known to use tools, but this is an uncommon practice. Even less common is tool making.

“Unlike something an animal finds in its environment, for example a stick for poking holes in to get bugs, these animals actually make and make and modify these tools and create optimal tools for specific environments,” said Andy Szabo, director of Alaska. Whale Foundation and first author on the paper.

This is far from the first time bubble nets have been documented. In particular, much has been written about humpback whales working together to hunt fish.

But Szabo says this paper, which focuses on single whale hunting krill, is unique because the scientists used new tools to take a deep dive (literally) into whale behavior. By deploying underwater cameras on animal tags and aerial cameras on drones, the researchers were able to see the exact structure of the bubble nets and the precise movements of the whales.

Humpback whales hunt krill using bubble net rings, according to the paper. Although krill are physically capable of swimming through bubbles, they are reluctant to cross them. Szabo said this could be due to the visual barrier created by the bubbles, but said this aspect of the nets is not fully understood.

As the nets get smaller and smaller, the groups of krill get deeper and deeper. On average, the paper found that the whales increased krill density sevenfold by using the nets. This means a whale must take fewer mouthfuls to eat, Szabo explains.

Humpback whales also appear to learn from each other through observation. Szabo says whales are not born blowing bubble nets. Instead, they learn how to do it through practice and by watching other whales. There is no evidence that whales intentionally teach others.

“They know they can blow bubbles and I think just by trial and error a whale learns a new trick, and if they are successful and they can improve it then they will continue to use it,” said said Szabo. “Other individuals in the area are watching what happens with the whale blowing the bubble net and doing well, and they will probably pick up on that as well.” He said there were at least 70 whales within two miles of the researchers’ boat all making bubble whales in the same way.

But the whales not only learned from each other, they also stole from each other. Some of the solo-hunters appear to take prey from the nets of other whales.

“What we saw was that in some instances one whale was making a bubble net and another whale came by and inhaled a mouthful of krill,” said Szabo, who said the behavior was not included in the set. of data.

Whales that fail the nets sometimes appear frustrated, Szabo said. He said that when the whales teamed up to hunt herring, it was common for them to drop their nets and rise to the surface looking “disturbed.”

What does anxiety look like in a whale? Szabo says they start making a wheezing, frustrated sound before diving down to try again.

The new paper provides great insight into bubble net feeding, said Olaf Meynecke, manager and researcher at the Whales and Climate research program at Griffith University in Australia. Meynecke is not involved in the new role.

“The study shows that humpback whales developed a way to catch prey, probably shared this knowledge with others, refined the technique and probably did it within a relatively short period of time,” said Meynecke.

He said whales have an outstanding ability to adapt and have also shown remarkable behavior in other areas, including research suggesting they can develop complex communication and cultural transmission of information.