Do Predators Only Kill out of Necessity?

Claim
Predators only kill out of necessity.

Origin
Take your pick here. From nature documentaries to animal rights advocates, the idea of nature existing in a constant state of balance where predators only take what they need is a popular narrative.

Facts
Simply put, predators kill for many reasons other than just eating what they need to survive. Wolves kill other wolves in territory disputes. Male bears kill cubs in order to create more breeding opportunities. Lions kill hyenas and hyenas kill lions over food. Well-fed domestic cats kill billions of birds and rodents in order to leave them on their owner’s porch.

Then there’s surplus killing. From weasels to wolves, predators occasionally kill more than they could possibly eat. The practice is most closely associated with the killing of confined, domestic animals like chickens or sheep, but it also happens in the wild.

For example, wolf packs have been known to lay waste to elk herds stuck in deep snow. It has been suggested that they may do this to cache food for later use, but there’s no clear evidence that surplus killing is a long-term survival strategy. It’s also plausible that the canines just get caught up in the chaos of the hunt, or their instincts drive them to get while the getting is good.

Clearly, predators kill for reasons other than keeping themselves fed. But we also need to avoid the “fox in the henhouse” assumption that predators engage in surplus killing for pleasure or greed. Likewise, when a grizzly bear wipes out a flock of sheep or wolves kill a herd of elk floundering in snow, it’s easy to say the predators are bloodthirsty or killing for fun.

Such labels are likely off the mark. These are wild animals that survive—even in normal conditions—by ripping the throats out of large ungulates, so it feels a little silly and anthropomorphic to impute some human emotion like fun or bloodthirstiness.

Takeaway
The truth is, nobody really knows why they do it. If a hungry predator comes across animals that don’t attempt to or can’t escape, perhaps it simply keeps killing because that’s what it’s programmed to do. The best and simplest explanation might be that predators are just being opportunistic, taking advantage of a situation they rarely encounter. In that case and others, a predator is killing, but not out of necessity.

Sources
Solving the mystery of bear cub killings — ScienceNordic
Staggering Stats: Cats Kill Billions of Animals a Year — Live Science
Wolf Pack Slaughters 19 Elk in Rare ‘Surplus Killing’ — National Geographic

Feature image via Wiki Commons.