Scientists have observed that humpback whales will often try to protect other animals from killer whales. Even more amazing, the behavior has been observed all over the world.
In 2009, the marine ecologist Robert Pitman was in Antarctica watching a pod of killer whales hunting a Weddell seal that they had trapped on an ice floe. The whales knocked the seal off the ice floe and were closing in for the kill when a humpback whale intervened to protect the seal. It surfaced and flipped onto its back so the seal could rest on its stomach. It even used its flippers to keep the seal from slipping off.
A few years, a BBC film crew saw humpback whales try to protect a gray whale calf that had gotten separated from its mother. This time, they weren’t successful, and the orcas killed and ate the youngster.
The most startling aspect of the whales’ behavior is its universality. The whales’ rescue efforts have been seen and reported from the North Pacific to Antarctica. Pitman began collecting accounts of the humpback whales’ interactions with orcas and found 115 documented episodes that had taken place between 1951 and 2012.
In 89 percent of the cases, the humpback whales approached the orcas only when they began to hunt or were in the middle of a hunt. Pitman realized the humpbacks were deliberately sabotaging the orcas’ hunts. The humpbacks have rescued harbor seals, California sea lions, ocean sunfish and gray whales. Pitman and other researchers have also noted that rescue whales typically work in pairs.
Of course, researchers would like to know why the humpbacks protect different creatures from orcas. Some have speculated that the apparently altruistic behavior may be aimed at protecting their own calves. While orcas can’t prey on healthy adult humpbacks, they can attack the young. The humpbacks’ rescue efforts may be a way of warning orcas away from their calves.