Barking Norwegian Lemmings Tell Predators to Back Off

If you try to go near a Norwegian lemming, you'll hear about it. The small rodent uses its distinctive bark and unusual coloring as a stern warning to those who would think to mess with it, a Swedish researcher has determined.

Making its living in Finland, Norway, Sweden, and the Kola peninsula in Russia, the Norwegian lemming (Lemmus lemmus) is reddish brown on its back, yellow on its sides, white on its chin and cheeks, and black on its head, neck, and shoulders.

It's rare for small rodents to make aggressive defenses of themselves, but the Norwegian lemming bucks that trend: It will scream loudly, lunge, and even bite aerial predators such as the long-tailed skua.

The video below (not part of the study) offers a glimpse of the lemming's defensive call in action.

Malte Andersson, of the University of Göteborg in Sweden, wanted to find out if the creature's audacious coloring and tendency to shriek under pressure served a purpose.

In field observations, Andersson found that Norwegian lemmings were overwhelmingly more likely than brown lemmings to issue a "be-gone!" warning call when a potential predator, such as a human, approached them.

Their coloring, meanwhile, was built to stand out. Observers in field tests found L. lemmus easier to pick out in their natural surroundings than the other most common rodent in the area, the grey-sided vole.Taken together, the coloring and behavior were thought by Andersson to be an instance of aposematism -- using coloration and other tactics as a warning to a potential predator that, in this case, some rodents are more trouble to mess with than they're worth.

Aposematism is more commonly seen in creatures such as frogs, snakes, and insects than in herbivorous mammals, making the little lemming stand out in a crowd yet again.

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