In 1958, Disney released a wildlife documentary called “White Wilderness.” One scene shows a small, brown-furred rodent, a lemming, slinking in the Arctic snow. “There is a true living legend,” the narrator declares, before diving into an explanation of the so-called lemming suicide myth.
In a turn of events, the film shows a large number of lemmings falling off a cliff. The survivors swim to the Arctic Ocean, where they eventually die, according to the narrator. So is this description accurate? Are lemmings really killed en masse?
The truth is that lemmings don’t intentionally jump to their deaths, scientists told LiveScience.
“They don’t do any of that” Andy Baltensperger, a landscape ecologist at the International Arctic Research Center at the University of Alaska Fairbanks told Live Science. “That’s just not how biology works.”
In fact, Disney he faked the whole scene, according to a 2003 article published by the Alaska Department of Fish and Game. TO 1983 investigation of the Canadian Broadcasting Corporation found that Disney filmmakers actually threw or pushed the lemmings off the cliff, using editing and tight camera angles to suggest that the lemmings were ending their lives on purpose. Disney did not respond to a request for comment from Live Science before this article was published.
Although the myth was completely invented, some known characteristics of lemmings could have inspired the scene and perpetuated the myth.
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First, lemmings are good swimmers. The swimming scene in the movie “White Wilderness” could have happened even without the director’s heavy hand. On many of the small islands of northern Norway there are populations of lemmings that have swam across lakes and rivers to reach new habitats. Dorothée Ehricha senior researcher at UiT, Norway’s Arctic University, told LiveScience.
But sometimes when lemmings swim through bodies of water, they may not find the other side, as they have terrible eyesight. Then the lemmings could drown, Ehrich said. However, he emphasized that the lemmings are not drowning on purpose as the Disney documentary claims.
In addition to their swimming ability, lemmings can be prolific breeders. Every three to five years, lemmings experience population surges that lead large numbers of them to run across the tundra. In these years, the population multiplies tenfold, Baltensperger stated.
“There’s a population explosion of animals all over the tundra, and it seems like they’re coming out everywhere,” he said. “They come into your store and you have to be careful not to step on them.”
Spikes in lemming numbers are likely related to food abundance and predation. During the winter, lemmings live beneath the snow cover and can access vegetation still growing on the ground. If they have a good supply of lichens, mosses, sedges and grasses, some species of lemmings can reproduce efficiently, Baltensperger said. In spring, they accumulate large quantities.
A large group of lemmings as shown in the Disney movie could be possible after a productive winter. However, the Canadian Broadcasting Corporation’s investigation found that the Disney film crew transported the group of lemmings and placed them on the edge of the cliff. Lemmings don’t jump, Balthensperger said, which may explain why, according to the 1983 report, the crew pushed the lemmings off the cliff.
Rather than intentionally committing suicide, biologists believe this boom-and-bust cycle of lemmings is likely driven by specialized predators. Stoats and weasels are especially adapted to hunting lemmings. They have long, thin bodies that fit into lemming tunnels under the snow, where they eat rodents and take over their winter nests.
Over time, the lemming population declines in response to overpredation, but not because of suicide by jumping, Ehrich said. As lemmings decrease in number or disperse across the landscape to find new resources, their predators are less effective and lemming populations have the opportunity to begin the cycle of abundance again.