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Killing off wild predators is a stupid idea

They're not serial killers, Quartz

Yathin S Krishnappa/Wikimedia Commons

The headline looked like a joke: "To truly end animal suffering, the most ethical choice is to kill wild predators (especially Cecil the lion)." Instead, it was an apparently serious opinion piece published earlier today on the news site Quartz. Walter Palmer — the infamous dentist who shot and killed Cecil the Lion — actually did the world a favor, the article says, since Cecil would have killed many more animals before he died. The authors argue that humans should hunt and kill predators in order to save prey animals from dying horrible deaths.

Several readers of the Quartz piece assumed it was satire. But Quartz's Editor-In-Chief, Kevin Delaney, told us in a Twitter direct message that it's "not satire; it’s an ideas piece on the issue." (The authors, Amanda MacAskill and William MacAskill, are — respectively — a philosophy Ph.D. student at New York University and an associate professor of philosophy at Lincoln College, part of Oxford University.) It's too bad they're serious; the arguments put forth are ridiculous. The piece is riddled with generalizations, faulty analogies, and propositions that have no evidence to support them. It is an embarrassment to ethicists, who typically have higher standards for public arguments.

"When I read the article in Quartz, I had to laugh."

"When I read the article in Quartz, I had to laugh, because I thought the article was written as a straw man to illustrate the many potential ethical points of view you can take regarding killing of top predators," Karl Cottenie, an associate professor of ecology at the University of Guelph, told The Verge. "The arguments made in the article seems relatively far-fetched."

The authors describe predators as murderers, comparing them to serial killers "intent on murdering several people over the next year." This is the anthropomorphic fallacy at work — projecting human emotions and attributes onto animals. It also serves as what philosophers call an "intuition pump," a problem framed in a specific fashion in order to elicit an author’s desired intuitive conclusion. Actually, predators aren't cold-blooded killers bent on destroying other animals' lives. Predators’ kills aren’t just necessary for their own survival; the kills also maintain a balanced ecosystem. It’s not a coincidence that keystone species — so named because they support an environment like a keystone supports a building — are predators. They eat quickly-reproducing prey that could otherwise overwhelm an area’s resources; this service lets animals that have slower reproductive cycles also have access to food.

So reducing the size of predator populations, even by a little, could have dire consequences. Prey animals might live longer, but their lives would be dominated by competing for food with other animals, and many — if not all — would eventually starve. This is to say nothing of the increased incidence of disease that comes with tightly-packed populations. "Let's say you kill the predators to prevent the prey from suffering." said Dan Blumstein, an ecologist at the University of California, Los Angeles. "That means there will be more prey, but they're going to suffer anyway. They'll become overabundant."

Red wolf stalking a deer. (Flickr CC by 2.0)

Case studies have shown that prey populations drastically increase when left unchecked by predation. For example, scientists found that in North American forests, deer populations averaged six times higher in places without wolves, compared to areas with the predator. A paper published in Science in 2011 found that the loss of lions and leopards in sub-Saharan Africa resulted in a giant increase in the region's baboon populations.

The increase in baboons, predictably, had consequences. The now more-numerous animals had to find new sources of food, so they started foraging closer to human-populated settlements. As a result, more people were infected with intestinal parasites that originated with the baboons. Arguably, intestinal parasites increase suffering in their hosts.

The authors use "predator" freely but don’t define it

This is something that the MacAskills actually seem to address. They write that "the cases that we are considering don’t involve a large-scale intervention." Rather, they want individual hunts, since those "are unlikely to have knock-on effects on the ecosystem of the region." On what evidence do they base this statement? None.

What evidence does show is that small changes, like a decline in a certain kind of predator, can have very large effects. A decline in insect-eating bird species worldwide, for instance, led to an increase in the pests they normally consume. That has, in turn, led to plant damage — damage that affects humans who rely on plants to live. These are the types of cascading effects that the authors seem to ignore entirely, probably because scientists barely understand these food web connections in the first place.

"The historical wildlife management record makes it quite clear that it is very tricky to anticipate the full range of complex ecological ramifications put into play whenever humans choose to cull top predators," says John Fryxell, a biologist also at the University of Guelph.

Male jumping spider, which is generally carnivorous. (Lukas Jonaitis/Wikimedia Commons)

That's not the only problem. There's a more basic one: the authors use "predator" freely but don’t define it. "Predators are everywhere," Blumstein said. Some predators, like cats or minks, are obligate carnivores — they cannot survive on plant-based diets. Other predators — humans among them — have more flexibility. Some predators are microscopic — do they count for the purposes of this argument? What about predators, like spiders or frogs, that eat pests like mosquitoes — which are themselves the source of suffering in their bites, and also in the diseases those bites transmit. What about predators like the killer whale, which prey largely on other predators like seals and sea lions?

The MacAskills suggest taking predators out of their natural environment and giving them "good lives that don't involve hunting prey." However, they offer no explanations for how to pull off such an incredibly labor-intensive and land-consuming endeavor, nor do they explain how obligate carnivores will survive on plant-based diets; asking a tiger to eat plants, food its body cannot process, for the rest of its natural life seems like a sure-fire cause of animal suffering. You know, for the tiger that is now starving to death.

Life is suffering; the only sure-fire way to avoid suffering is to die

It’s not enough to state that "interventions" — what interventions? — "could be justified following a rigorous risk analysis." (One thinks of Ben Franklin: "So convenient a thing it is to be a reasonable creature, since it enables one to find or make a reason for everything one has a mind to do.") What the MacAskills are asking is that we undertake tremendous ecosystem upheaval and damage, at staggering expense and at considerable risk to the lives of people involved — to "prevent suffering."

Life is suffering; nature is red in tooth and claw, as Lord Tennyson rightly noted. Pain is an exquisite warning system, meant to keep an animal alive; the only sure-fire way to avoid suffering is to die. Perhaps, then, the true way to alleviate suffering is to increase, rather than decrease, the number of predators. There will be more deaths — and more animals that are no longer suffering, for that very reason.