Biologists have observed several instances of humpbacks rescuing seals, sunfish, and other species from killer whales. They may be doing this by mistake or for some unknown reasons, but they might also be empathizing with these creatures and attempting to save them for altruistic reasons.
In May 2012 researchers witnessed a mind-bending scene. A pod of killer whales was attacking a gray whale and its calf. After a struggle, the calf was killed and the pod moved on to the big whale. Things got really weird after that.
“One specific humpback whale appeared to station itself next to that calf carcass, head pointed toward it, staying within a body length away, loudly vocalizing and tail slashing every time a killer whale came over to feed,” Alisa Schulman-Janiger, a whale researcher with the California Killer Whale Project told National Geographic.
For six and a half hours, 14 humpbacks violently defended the whale and its calf carcass. Although thick swarms of krill were spotted nearby (which humpbacks enjoy eating) and although they themselves risked getting injured, they did not budge. Although they arrived too late for the calf, they defended the mother. This was not an isolated event.
In the last 62 years, there have been 115 recorded interactions between humpback whales and killer whales, according to a study published this July in the journal Marine Mammal Science. Of course, researchers have been able to intercept only an extremely small fraction of them, so exactly how many similar interactions there were is anyone's guess.
“This humpback whale behavior continues to happen in multiple areas throughout the world,” says Schulman-Janiger, who coauthored the study.
Why whales do this
Generally, when animals do something, they either get a benefit from it or have some kind of instinctual behavior. It may be the later case here, as orcas (killer whales) have been known to attack humpbacks, especially when they are young. A full-grown humpback whale could challenge an entire orca pod and still win, so perhaps they've developed this defensive strategy to help other animals get through their young stage in life.
But this doesn't explain why they're helping other species. In fact, in just 11% of the recorded interactions humpbacks were protecting other humpbacks. In the other instances, they protected seals, sea lions, porpoises, and other marine mammals. There's even one event where they defended a pair of ocean sunfish from becoming orca food.
Another explanation would be that it's personal. Biologists have noted that not all humpbacks defend other creatures. Most individuals that do however bear scars from orcas, likely obtained as a calf. So maybe they just hate killer whales and are trying to thwart their efforts. If this is the case, then it's a fantastic example of sophisticated and complex thinking. Hate is a strong empathetic response and one that humpbacks are probably capable of.
“Although this behavior is very interesting, I don’t find it completely surprising that a cetacean would intervene to help a member of another species,” says Lori Marino, an expert in cetacean intelligence and president of the Whale Sanctuary Project.