A recent study describes how researchers closely observed humpback whales in Southeast Alaska using advanced technology including drones and special tags that monitor their movements and behaviours. What they’ve discovered is fascinating: humpback whales create intricate bubble-nets by releasing air from their blowholes while swimming in circles. These bubbles rise to the surface, forming a net-like structure that traps krill and small fish.

Tool use in animals

Several mammal, bird, fish, and insect species are known to use tools, but such behavior remains relatively rare across the animal kingdom. Even less common are species that go beyond simple tool use to actually manufacture or modify their tools. Notable examples include chimpanzees and orangutans, who create specialized tools to extract insects and fruits, and New Caledonian crows and Goffin’s cockatoos, who craft wooden tools to access vegetation and seeds. The process of making these tools involves a series of complex actions, such as selecting and modifying natural materials to fit specific needs. This advanced behaviour, combined with the larger and more complex brains of these species, has led researchers to suggest that the rarity of tool use and manufacture may be limited by cognitive constraints across different species. It is therefore telling in terms of their intelligence, that humpback whales are now included among the animals who create and use tools.

A precise method

Here’s how it works: the whales produce the bubbles in distinct bursts, not continuously. They can adjust the size, depth, and spacing of the bubbles to fine-tune their net. This ability to control the net's design allows them to increase their prey intake significantly—by up to seven times—without using extra energy. 

The study found that these bubble-nets are made up of several rings, each one smaller than the last, creating a tight mesh that keeps their prey from escaping. The whales start creating these nets at an average depth of about 22 meters and can go deeper while making the net, which means they can catch prey more effectively as they dive.

A proven technique

Interestingly, each whale tends to follow a similar pattern in how they create their nets, suggesting that there’s a consistent method behind their technique. This innovation not only helps them catch more food but also allows them to hunt in areas where prey might be less dense, making it a smart strategy for survival.

In summary, humpback whales have mastered a remarkable foraging tool that enhances their feeding efficiency while conserving energy. This clever technique helps them thrive even when prey is sparse, showing just how adaptable and intelligent these magnificent creatures are. Future research will likely explore how these bubble-nets might change under different conditions or when whales work together, offering even more insights into their fascinating hunting skills.