One morning the scientists chugged up to ten orcas and found them in some kind of splashy muddle with a couple much-larger humpback whales. Bellowing like crazy, the humpbacks were whacking the water's surface with flippers and tails. The orcas were milling around. Then they moved on. The researchers guessed the orcas might have been checking to see if the humpbacks could be weak enough to attack. But when they looked at their video, they noticed a Weddell seal in the melee, between the humpbacks, and wondered if the orcas had been after the seal.
The scientists pursued the pod of orcas, who soon spotted a crabeater seal relaxing on an ice floe. Oho! Inconsiderately, the orcas generated a wave which broke the floe into pieces. The seal, “distraught,” was now on a much tinier floe. Before the orcas could make their next move, the same humpbacks appeared. Again with the bellowing and splashing! As Pitman and Durban recount in the November 2009 Natural History the orcas “seemed annoyed,” and took off without harassing the seal further. Hmm, “mobbing behavior,” the researchers concluded. Interesting.
Next week they were spying on a different batch of orcas, attacking a different Weddell seal on a different ice floe, when who should appear but a different pair of humpbacks. The orcas had actually knocked the seal into the water, but before they could grab it, the seal swam toward the humpbacks. When it got to the closest one, the humpback rolled onto its back in such a way that the seal was swept up onto the humpback's chest. The humpback arched its body to lift the seal above the water, nudging it with a flipper so it didn't slide off. “Moments later, the seal scrambled off and swam to the safety of a nearby ice floe.” A bigger one, I presume.
Pitman and Durban changed their speculation from “mobbing behavior” to “maternal behavior.” They refer to “allomaternal care.” They go on say that while this is called instinct when it's seen in a whale, when a human does it “we call it compassion.... But sometimes the distinction isn't all that clear.”
My guess is that yes, there was compassion. The humpbacks felt sorry for terrified seals. But maybe they also disapproved of the orcas' behavior. They sound outraged. Buncha violent creeps terrorizing pipsqueaks. Can't someone relax on some ice without you guys ruining everything? You make me feel like bellowing! Put that pinniped down! Why don't you pick on someone your own size? Bite this!
This suggestion certainly leaves me open to charges of anthropomorphism. But the outrage people feel when they see bullies picking on a weakling doesn't necessarily arise from the most abstractly intellectual workings of our fabulous neocortex. Like compassion, maybe it's more visceral than that. Maybe it comes from the bottom of the heart.
*Orcinus orca (Linnaeus). People have various views on “killer whale” versus “orca.” Is it calumny to call them killers? Is it sentimental PC-ishness to call them orcas? (Are you calling Linnaeus PC?) This article called them killer whales. I use both terms. Mostly orca, because it's shorter.