[♩INTRO].

Orcas are sometimes referred to as the wolves of the sea. When hunting, they work together as a pod to single out a young or injured animal and take it down for their next meal -- much like wolves do.

They’ll even target young humpback whales. But adult humpbacks are big enough to fight back and win, against an entire pod of hungry orcas. And they will fight fiercely to protect their own kind.

But weirdly enough, humpbacks will also swoop in to defend other creatures being targeted by orcas. This comes as a complete surprise to researchers. We don’t expect animals to act in a way that doesn’t directly benefit their own species, especially when it involves interacting with one of their natural predators.

So the question before scientists is:. Are these gentle giants just practicing for the next time one of their own is under attack, or have they decided to become the superheroes of the sea? Humpback whales are so large that they don’t have much in the way of natural predators.

Nothing is bold enough to try to take on a whale weighing over 30 tons. Nothing, that is, except a pod of hungry orcas. Orcas regularly attack humpback whale calves and juveniles, risking the wrath of the mother whale as well as any others nearby.

These attacks are rarely witnessed, but many humpbacks bear scars of attacks on their flukes. Researchers estimate that up to a third of all humpbacks have tangled with an orca at some point in their lives. Since they don’t have teeth, humpbacks use their enormous bodies and oversized fins and tail as weapons.

And these giants don’t wait to be attacked to bust out their incredible defensive moves. They have been observed rushing in to defend others in need. But, more often than not, they are coming to the defense of a completely unrelated species under attack.

A 2016 study looked at over 60 years of observations of humpbacks interfering with an orca attack. They were surprised to find that the animal being attacked was another humpback whale only 11 percent of the time. The other 89 percent was a mixed bag of species, including other whales, seals, sea lions, porpoises, and even some fish!

These rescues can last hours, with multiple humpbacks getting involved and not giving in until the orcas finally decide to back off. Which, as you can imagine, comes at a huge energy cost for the humpbacks. Not to mention, it takes away from their regular activities, like feeding and resting.

So researchers aren’t exactly sure why these whales go to great lengths, risking injury and energy, to protect those that aren’t even their own species. They suggest the whales’ behavior may benefit their own species just often enough that it persists. Some have even proposed that humpbacks could have a soft spot for others under attack, because some of the whales rushing to the rescue have scars from previous orca attacks.

We can’t really know what’s in their heads, though. Or it could be simply be that the whales always rush in when there’s an orca fight. Because at least some of the time, they are swooping in from several kilometers away, too far to see who’s in trouble.

That means they don’t know who the victim is, they’re only responding to the sounds the orcas are making as they go in for the kill. It’s clear we still have a lot left to learn about why the whales behave this way. But one thing is for certain:.

They’re the heroes of a grateful ocean! Thanks for watching this episode of SciShow, which was brought to you with the help of our patrons. Patrons get access to neat perks, like a Discord server where you can chat with members of our team.

If you’re interested in joining, check out patreon.com/scishow. [♩OUTRO].