Humpback whales manufacture and wield tools

This video from 2019 provides an overview of humpback whales and their ability to create bubble nets to trap prey. Via University of Hawaii at Manoa.

• Humpback whales have long been known to create bubble nets for hunting.
• The whales should be considered “tool wielders,” says a new study. That’s because the study shows whales manipulating the bubble nets in a variety of ways, to maximize their food intake in their Alaskan feeding grounds.
• The scientists used suction-cup tags and drones to study these behaviors among whales.

Humpback whales as tool wielders

It’s long been known that humpback whales near the ocean surface sometimes feed by blowing bubbles to corral prey like krill and small fish. In the jargon of scientists, the whales are using bubble nets. What’s fascinating is that the bubble nets are, in essence, tools created by the whales. Now, a new study shows that the whales are able to manipulate their bubble net tools, to maximize the amount of prey they catch. This result has prompted these scientists to label the whales as tool wielders.

Lars Bejder, co-lead author of the study and director of the Marine Mammal Research Program at the UH Hawai’i Institute of Marine Biology, explained in a statement:

Many animals use tools to help them find food. But very few actually create or modify these tools themselves.

We discovered that solitary humpback whales in southeast Alaska craft complex bubble nets to catch krill, which are tiny shrimp-like creatures. These whales skillfully blow bubbles in patterns that form nets with internal rings, actively controlling details like the number of rings, the size and depth of the net, and the spacing between bubbles. This method lets them capture up to seven times more prey in a single feeding dive without using extra energy.

This impressive behavior places humpback whales among the rare group of animals that both make and use their own tools for hunting.

This study was published in Royal Society Open Science on August 21, 2024.

Last week at Icy Strait Point Alaska we skipped the whale watching zodiac tour. As happy hour started, I saw a peculiar circle of bubbles next to the ship and took out my phone just in time to record a humpback whale bubble net feeding. Astounding! pic.twitter.com/UQlToqNB8K

— Randy Nesse (@RandyNesse) July 6, 2024

Humpback whales shape bubble nets for better hunting

There are several populations of humpback whales worldwide. But the whales in this study spend the summer and fall feeding off the coast of southeast Alaska. There, they feed intensively to build up fat reserves. That’s because they’ll need that stored fat to sustain them as they migrate to waters off Hawaii where they spend the winter months. And during that time, they do not feed.

To accomplish the huge task of feeding themselves, these humpback whales (Megaptera novaeangliae) exhale complex bubble structures from their blowholes. They do this while swimming in a circular path below their prey. The rising bubbles form vertical “nets” that disorient and direct prey, such as krill and small fish, into a tight area where they can be easily swallowed.

This feeding behavior has been seen in individual whales and also in cooperative hunting groups. In this study, scientists reported on the feeding strategy of individual humpback whales in waters off southeast Alaska.

How scientists studied the whales

Scientists used tags with motion sensors and video cameras to study the humpback whales. These tags were temporarily suction-cupped to five whales to track their movements. In addition, the researchers used drones to monitor the whales from above. Data from this equipment allowed them to reconstruct a three-dimensional view of the whale’s foraging techniques with bubble nets.

William Gough, also of the University of Hawai’i at Manoa, said:

We deployed non-invasive suction-cup tags on whales and flew drones over solitary bubble-netting humpback whales in southeast Alaska, collecting data on their underwater movements. Whales are a difficult group to study, requiring skill and precision to successfully tag and/or drone them.

This little-studied foraging behavior is wholly unique to humpback whales. It’s so incredible to see these animals in their natural habitat, performing behaviors that only a few people ever get to see. And it’s rewarding to be able to come back to the lab, dive into the data, and learn about what they’re doing underwater once they disappear from view.

And Bejder said their research will guide further study of M. novaeangliae:

This is a rich dataset that will allow us to learn even more about the physics and energetics of solitary bubble-netting. There is also data coming in from humpback whales performing other feeding behaviors, such as cooperative bubble-netting, surface feeding, and deep lunge feeding, allowing for further exploration of this population’s energetic landscape and fitness.

Efficient hunting is key to whales’ survival

Understanding how cetaceans, such as humpback whales, hunt helps resource managers monitor and conserve habitat in the waters where they feed. That’s because these creatures face many threats, such as climate change, degraded habitats and overfishing, as well as chemical and noise pollution. Andy Szabo, of the Alaska Whale Foundation, commented in the statement:

What I find exciting is that humpbacks have come up with complex tools allowing them to exploit prey aggregations that otherwise would be unavailable to them. It is this behavioral flexibility and ingenuity that I hope will serve these whales well as our oceans continue to change.

Bottom line: Humpback whales create and manipulate bubble nets as tools. Alone and in groups, the whales use the nets to encircle prey and maximize their catch.

Source: Solitary humpback whales manufacture bubble-nets as tools to increase prey intake

Via University of Hawai’i at Manoa

Read more: Whales are the biggest living animals: Lifeform of the week

The post Humpback whales manufacture and wield tools first appeared on EarthSky.