Bubbles are surprisingly important to a wide range of cetaceans. Different species use them for play, to help capture prey, and even in aggressive encounters. Now, researchers are looking at bubble rings made by humpback whales to learn more about why the species makes such a specific shape.
Humpback whales have a wide range of bubble-based creations, from the cooperatively made spiral bubble nets to clouds of bubbles that rise through the air. The team were particularly interested in bubble rings that rise up through the water column and resemble smoke rings blown from a pipe.
“Humpback whales live in complex societies, are acoustically diverse, use bubble tools and assist other species being harassed by predators,” said co-lead author Dr Fred Sharpe, UC Davis Affiliate, in a statement.
The team looked at “12 ring-production episodes involving 39 bubble rings produced by 11 individual humpback whales,” they explained in their paper. The aim was to find out more about why the humpbacks were producing this specific type of bubble.
The images and videos of the bubble rings were obtained from a variety of sources, including whale watching trips, small planes, and private vessels. The team also looked at footage from drones to see if the bubble rings were still produced in the absence of humans.
All the ring episodes showed the whales were either still in the water or moving very slowly forward. One episode showed the ring emerging from only the right nostril of the whale. Two of the 12 cases saw the bubble rings emerge in line with suspected predation on sand lance and the creation of a bubble net.
Ten of the 12 episodes of bubble ring production were made in the presence of humans or swimmers near the whales, and six of the 12 had more than one whale present. The team report no aggression either towards people or other whales in these events and instead believe that the whales were relaxed and even inquisitive in these situations.
“Humpback whales often exhibit inquisitive, friendly behavior towards boats and human swimmers,” said co-lead author Jodi Frediani, marine wildlife photographer and U.C. Davis Affiliate. “We’ve now located a dozen whales from populations around the world, the majority of which have voluntarily approached boats and swimmers blowing bubble rings during these episodes of curious behavior.
The paper is published in Marine Mammal Science.
Source Link: Watch Inquisitive Humpback Whales Blow Bubble Rings At Whale Watchers