Scientists Can’t Figure Out Why Humpback Whales Are Saving Animals From Orcas

Humpbacks are heroes!

Humans and apes have long been believed to be the only creatures who care about the wellbeing of animals, but a series of interesting studies and observations are coming together to add another animal to that list: humpback whales. All over the world, researchers have recorded incidents of humpback whales disrupting orca pods’ hunts. In one observation in the Weddell Sea, off Antarctica, marine researcher Robert Pitman witnessed a pod of killer whales employing one of the species’ many hunting methods: swimming in a line toward an ice floe and diving under at the last minute. With a flip of their tails, the orcas created a wave that knocked their prey off the ice.

But at the last minute, when the seal had been knocked into the water, a humpback whale rose from beneath it to remove it from harm’s way. And it wasn’t just by chance: As the seal started to slip and slide, the humpback whale used its flippers to keep the seal in place until the orca pod moved on and the seal could swim safely away. A BBC film crew captured footage of another intervened hunt, in which a grey whale calf was separated from its mother. Orcas began to attack, before two humpback whales formed a barrier around the struggling calf. After Pitman witnessed the seal-saving incident in 2009, he was intrigued and began studying humpback whale behavior all around the world. He found more than 100 observations of humpback heroism by 54 different researchers between 1961 and 2012. He found that 87% of the time, when humpback whales approached orcas, it was to intervene in hunting behavior. Of those instances, 11% involved humpbacks protecting their own calves, while 89% involved protecting seals, sea lions and grey whale calves.

While these uneven percentages may seem to indicate a neglect of their own kind, it’s not: What it really means is that, while humpbacks will always try to save members of their own pod, they will also go out of their way to protect other species. That’s undeniably altruistic behavior. Pitman ruled out the possibility that only a certain pod was participating in these aquatic rescue missions (though he did manage to identify one humpback that participated in two rescues 15 years apart) by tracking the locations of reported humpback interruptions of orca attacks.

Pitman’s research showed that the humpbacks were not always successful in their interventions. But interestingly, they were successful in 4 out of 5 observed attacks on humpback calves, perhaps noting a stronger motivation to save calves of their own kind.

But why are humpback whales doing this?

The leading theory is that adult humpback whales are attempting to teach orcas not to mess with them. While adults are too large to be killed effectively by orcas, humpback calves are often hunted. Some believe that in protecting other grey whale calves and even seals, humpback adults are sending a stronger warning message. In looking out for their neighbors as well as their own young, humpbacks may be trying to send a clear message: In order to get to our babies, you’ll have to go through us first.

Other researchers believe it’s a form of altruistic revenge from previous times when orcas attacked a humpback’s “family.” But no matter the inspiration, the disruption of orca hunting by humpbacks signifies a complex emotional processing system not otherwise identified in the animal kingdom outside humans and primates. Only continued study can provide the answers researchers are looking for, but in the meantime, we can count on humpback whales to be the ocean’s leading protectors.