Recently, biologist Nan Hauser was snorkeling in the Cook Islands in the South Pacific, when she was approached by a humpback whale. The whale nudged her forward with its closed mouth, tucked her under its pectoral fin, and even maneuvered her out of the water with its back. Hauser was initially frightened and confused by the humpback’s behavior. Only when she got out of the water did she see a large tiger shark on the far side of the whale. Hauser concluded that the whale was attempting to protect her from the shark.

While her conclusion might initially sound far-fetched, for at least the last sixty years, scientists have observed, without quite understanding what they were seeing, a series of strange and stunning events — humpback whales appearing to launch coordinated rescue missions to prevent seals and other whales from being attacked by orcas. Hauser’s experience may be just another form of this not well-understood humpback behavior.

Mother Nature Network reports of similar intentional rescues:  Marine ecologist Robert Pitman observed a particularly dramatic example of this behavior back in 2009 while observing a pod of killer whales hunting a Weddell seal trapped on an ice floe off Antarctica. The orcas were able to successfully knock the seal off the ice, and just as they were closing in for the kill, a magnificent humpback whale suddenly rose up out of the water beneath the seal. 

This was no mere accident. In order to better protect the seal, the whale placed it safely on its upturned belly to keep it out of the water. As the seal slipped down the whale’s side, the humpback appeared to use its flippers to carefully help the seal back aboard. Finally, when the coast was clear, the seal was able to safely swim off to another, more secure ice floe.

The BBC has also recorded video of humpback whales attempting to save a baby gray whale which had become separated from its mother and was under attack by a pod of orcas.  

Robert Pittman went on to study the phenomenon. His research analyzed 115 interactions that took place between humpbacks and killer whales, observed by more than 54 individuals — scientists and non-scientists — in ocean locations around the world and spanning 62 years, from 1951 through 2012.

The study found that large and powerful humpback whales, the only whales known to attack orcas, will band together and sometimes travel great distances to interrupt and terminate a killer whale attack, regardless of what type of animal the orca is attacking.

Was This Whale Trying to Save a Diver’s Life? | National Geographic