Inside the Mystery of Animal 'Suicide'

The first I heard about animals suiciding was after getting up close with tarsiers, a type of primate found in the Philippines. These teeny-tiny Yoda lookalikes are nocturnal and loathe noise and human contact; the misery of being stuck in a never-ending line of selfie opps—such as the one I joined at a so-called tarsier “sanctuary”—can cause them to bang their tiny heads against the cage until they die. Of course, I only discovered this after I left. And I felt awful.

Tarsiers aren’t the only species prone to suicide. Records of animals taking their own lives date back to ancient times, with Aristotle writing about a case of a stallion who threw itself into an abyss after it realised it had unknowingly mated with its mother. Animal experts and media have been similarly intrigued ever since: scientists still don’t know what motivates groups of healthy whales to beach themselves, and lemmings have earned themselves a place in popular culture by throwing themselves off cliffs en masse.

Modern-day fascination with the topic appears to have started in Victorian England. A London news article in 1845 reported on a dog who appeared to be trying to drown itself. After being repeatedly rescued, "it again rushed in, and at last determinedly held its head under water until life was extinct." A growing number of reports then circulated during the 1870s and 1880s: a duck that drowned itself; a cat that hanged itself from a branch following the death of her kittens. Timing-wise, the examples seemed to bounce off the emerging idea that animals also had inner lives, and should therefore be spared pain and suffering.

There have been more recent cases of animals supposedly killing themselves, especially after experiencing unspeakable cruelty at the hands of humans. In China in 2011, a captive bear was reported to have smothered her cub and then killed herself after the cub was subjected to the extremely painful insertion of a catheter into its abdomen to extract bile. According to someone who claims to have witnessed the procedures on the grotesque “bile farm”, and was quoted in Reminbao.com:

"The mother bear broke out its cage when it heard its cub howl in fear before a worker punctured its stomach to milk the bile … Unable to free the cub from its restraints, the mother hugged the cub and eventually strangled it. It then dropped the cub and ran head-first into a wall, killing itself."

The use of the term suicide is “iffy” in a scientific framework because it requires us to prove an animal's conscious intention to die, says Barbara King, anthropologist and author of How Animals Grieve. “How can we reliably measure such a thing?” she asks.

Nonetheless, King points to dolphins as perhaps the strongest indication that suicide does happen in the animal kingdom. She says dolphins have been known to hold their breath until they die when faced with certain death from hunting, or when being cruelly confined. “Dolphins are conscious breathers and they are extremely intelligent, to the extent of being able to plan in complex ways, so perhaps suicide is within their realm of choice.”

Dr David Pena-Guzman from San Francisco State University has written extensively on the subject, and believes animals are capable of self-destructive behaviour. “There is also evidence that animals have rich emotional lives,” he says, “and experience negative emotions such as PTSD, depression, complicated grief and so on, which are commonly recognised as precursors to suicide.”

Some pets, argues Pena-Guzman, can actually die of grief when they lose their owner, just as we are gutted when they pass away. “Animals whose human companions die can be devastated by the loss,” he says. “In some cases, they sink into a depression so deep and so dark that they simply lose their will to live. They stop eating and die.”

However, Antonio Preti, a psychiatrist at the University of Cagliari, thinks that this is humans projecting our specific type of grief onto animals. He told the BBC that these pet deaths can be explained instead as the disruption of a social tie: “The animal does not make a conscious decision to die; instead, the animal was so used to its master that it no longer accepts food from another individual.”

Some animal behaviours that appear to be suicide are something else entirely, other experts say. Take whales: they are social creatures, so when one member of the group gets sick and seeks safety in shallow water, the others follow suit. They don’t necessarily do it with the intention of ending their lives.

Nor do lemmings suicide—that’s an urban legend we can blame on Disney. Lemmings choose to migrate in big groups when the population gets too dense and they overgraze their immediate environs. They are seeking out new habitats and may accidentally die in the process, such as by falling down a steep slope or drowning in a river.

Another freakish example is spiders. Mother spiders will sometimes allow themselves to be eaten alive by their babies. It’s not suicide, as such, but a selfless way of giving their offspring their first nutritional meal, which helps to ensure their survival.

Although there isn’t consensus in the scientific world about whether animals are capable of dying by suicide, Pena-Guzman credits the study of animals as having taught us a lot about suicide in humans. “Most of our knowledge of human suicide, including knowledge of its causes, comes from inferences about human suicide from animal research,” he says. “This makes sense only if there are strong parallels—biological, neurological, psychological, cognitive and social—between humans and animals relevant to suicide. These parallels further support the idea that animals have what it takes to suicide.”