29 March: Lemming Day

Today is Lemming day. 10 facts about lemmings:

1. There are about 19 species of lemming. They belong to the family Cricetidae and are most closely related to Hamsters, voles and muskrats.

2. They are native to USA, Canada, Norway, Sweden, Greenland, China and Russia.

3. The different species vary in size but on average they are 7-14cm in length (not including their tails) and weigh between 30g and 115g.

4. They don’t hibernate in winter. Those living in extremely cold climates will burrow in Snow to keep warm and eat tree bark and twigs. In summer they eat grass, moss, berries, shoots and roots.

5. They are solitary creatures as a rule, only coming together to mate. Although it has to be said, they mate a lot. The breeding season is usually during the warmer summer months from June to September, although some especially determined (or randy) individuals may start mating in January. In the summer the females are continually pregnant and can produce two or three litters of about seven (but possibly as many as 13) each year. The young are sexually mature after just two weeks and can start producing litters of their own.

6. It has been observed that lemming populations fluctuate wildly. Some years there will be lots, others they may seem to virtually disappear altogether. There have been a number of wacky theories which try to explain this, dating back to 1532 when Jacob Ziegler put forward the suggestion that lemmings fall from the sky during storms, and die when the first grass grows in spring.

7. Whatever the reason, one thing it definitely isn’t is that they throw themselves off cliffs in huge numbers when the population gets too large. This is a myth perpetrated by Disney. Although the concept dates back to the 19^th century when a magazine called Popular Science Monthly suggested that lemmings throw themselves in the sea so they can swim off in search of the lost continent of Lemuria. And no, this article appeared in August, not April 1^st! A 1958 Disney documentary called White Wilderness is to blame for popularising the myth, as it included footage of lemmings running across the tundra and apparently throwing themselves off a cliff. It was completely staged involving snowy turntables, clever editing, and it has to be said, a lot of cruelty to lemmings. The truth came out in 1983 and the backlash from scientists and animal rights activists resulted in White Wilderness being removed from the list of films on Disney’s website.

8. A much more likely explanation is that, while lemmings don’t migrate en masse, they will disperse if an area gets too crowded, in search of food and territory. They might tend to go in the same direction but not as a pack. They can swim, and might attempt to cross a river if it’s in their path, but will avoid doing so if they can. If they drown, it’s not intentional.

9. In the 90’s there was a popular video game called ‘Lemmings’, where players had to guide lemmings through various obstacles to stop them killing themselves.

10. Even if they get lucky, they only live for a year or two. They are seen as a tasty snack by many predators like Foxes, weasels, Owls, Wolves, wolverines, hawks, gulls, and falcons. There’s another myth that lemmings will explode if threatened. Needless to say it’s not true, but they will expose their sharp teeth and screech.