Male killer whales need friends to survive

October 26, 2017, 8:18 a.m.
A trio of killer whales near each other
Photo: Chris Curtis/Shutterstock

It's tough being the outsider, especially if you're a killer whale.

A study conducted by researchers from the University of Exter, the University of York and the Center for Whale Research and published in the journal Proceedings of the Royal Society B found that male southern resident killer whales that exist on the fringes of social groups were three times more likely to die than males that had more central positions in the group.

"This research highlights the importance of social bonds to male killer whales, and shows that males that are less socially connected are more likely to die when times are hard," the study's lead author, Samuel Ellis, of the University of Exeter, said in a statement.

So what's the cause of the increased risk of death? Do the other whales just compile a really nasty "Mean Girls"-inspired burn book about the ostracized whales? Can the other whales simply not even be around these social outcasts?

The primary driver appears to be access to salmon. In years with lower-than-usual salmon, the males at the center of a social group have an easier time learning about spots where salmon can be found by following females, and whales, particularly females, share food with other whales they're close to. So male whales with more friends have better access to food.

If this is the case, why don't these whales do a bit more networking when there's less salmon readily available? Ellis and his team suggest in the study that it's a matter of trade-offs. When there's less food, whales need to spend more time foraging. This is especially important for male whales, which are heavier and require an estimated 25 percent more intake than females do.

But since they're constantly foraging for food, these wallflowers of the whale world don't have the time to invest in social interactions; they're too busy trying to eat to survive. It also doesn't help that some whales just choose to ignore these outsiders entirely during times of low salmon abundance, even if they're related to them, so as to reduce the local competition for salmon.

So even if the whales try to put in the social work necessary, it's possible that the other whales will simply keep them at bay.