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DisprovedChanged1983

Lemmings commit mass suicide by jumping off cliffs

The old claim turned out to be wrong and was rejected by evidence.

TaughtWhen lemming populations get too large, the animals instinctively march to the sea and hurl themselves off cliffs to thin the herd.

NowLemmings do not commit suicide. The belief comes largely from Disney's 1958 documentary White Wilderness, in which the filmmakers threw the animals off a cliff themselves.

What actually happened

The film won an Academy Award for Best Documentary Feature. The lemming sequence was staged. The animals were bought from Inuit children, filmed on a turntable to simulate a migration, and then driven off a cliff into a river by the crew. A 1983 CBC investigation documented how the scene was made.

The biology underneath is real but different. Lemming populations do boom and crash on roughly four-year cycles, and during booms the animals disperse in large numbers looking for territory. Some drown crossing water they misjudge. That is a navigation failure during migration, not a suicide instinct, and evolution has no mechanism to select for individually fatal population control of this kind. The idea persists because a beloved documentary staged it convincingly.

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Sources

  1. Encyclopaedia Britannica: Do lemmings really commit mass suicide?britannica.com
  2. Alaska Department of Fish and Game: Lemmingsadfg.alaska.gov

Who was taught this

Still standard through 2000, so anyone who finished school between 1950 and 1983 learned the earlier version.