Lemmings are small
rodents,
usually found in or near the
Arctic, in
tundra
biomes. They are
subniveal animals and together with the
voles and
muskrats, they make up
the
subfamily Arvicolinae (also known as Microtinae), which
forms part of the largest
mammal radiation by far, the superfamily
Muroidea, which also includes the
rats,
mice,
hamsters, and
gerbils.
Description and habitat
Lemmings weigh from and are about long. They generally have long,
soft fur, and very short tails. They are
herbivorous, feeding mostly on leaves and shoots,
grasses, and
sedges in particular, but also on roots and
bulbs. Like other rodents, their
incisors
grow continuously, allowing them to exist on much tougher forage
than what would normally be possible.
Lemmings do not
hibernate through the
harsh northern winter. They remain active, finding food by
burrowing through the snow and utilizing grasses clipped and stored
in advance. They are solitary animals by nature, meeting only to
mate and then going their separate ways, but like all rodents they
have a high reproductive rate and can breed rapidly when food is
plentiful.
Behavior
The behavior of lemmings is much the same as that of many other
rodents which have periodic population booms and then disperse in
all directions, seeking the food and shelter that their natural
habitat cannot provide.
Lemmings of northern Norway
are one of
the few vertebrates who reproduce so quickly that their population
fluctuations are chaotic, rather than following linear growth to a
carrying capacity or regular oscillations. It is unknown why
lemming populations fluctuate with such variance roughly every four
years, before plummeting to near extinction.
While for many years it was believed that the population of lemming
predator changed with the
population cycle, there is now some
evidence to suggest that the predator's population may be more
closely involved in changing the lemming population.
Myths and misconceptions
Misconceptions about lemmings go back many centuries.
In the 1530s, the
geographer Zeigler of
Strasbourg proposed the theory that the creatures fell out of
the sky during stormy weather (also featured in the folklore of the Inupiat/Yupik at Norton Sound
), and then died suddenly when the grass grew in
spring. This myth was refuted by the natural historian
Ole Worm, who accepted that the lemmings
could fall out of the sky but that they had been brought over by
the wind rather than created by
spontaneous generation. It was Worm
who first published dissections of a lemming, which showed that
they are anatomically similar to most other rodents, and the work
of
Carl Linnaeus proved that the
animals had a natural origin.
When large numbers of lemmings get on
the move, some of them will inevitably drown while crossing rivers
and lakes, like this one in Norway.
While many people believe that lemmings commit
mass suicide when they migrate, this is not the
case. Driven by strong biological urges, they will migrate in large
groupings when population density becomes too great. Lemmings can
and do swim and may choose to cross a body of water in search of a
new habitat. On occasion, and particularly in the case of the
Norway lemmings in Scandinavia, large
migrating groups will reach a cliff overlooking the ocean. They
will stop until the urge to press on causes them to jump off the
cliff and start swimming. They then swim to exhaustion and death.
Lemmings are also often pushed into the sea as more and more
lemmings arrive at the shore.
The myth of lemming mass
suicide is
long-standing and has been popularized by a number of factors. In
1955,
Disney Studio
illustrator
Carl Barks drew an
Uncle Scrooge adventure comic with the title
"The Lemming with the Locket".
This comic, which was inspired by a 1954
National
Geographic Society
article, showed massive numbers of lemmings jumping
over Norwegian cliffs. Even more influential was the 1958
Disney film
White
Wilderness, which won an
Academy Award for
Documentary Feature, in which footage was shown that seems to
show the mass suicide of lemmings. In more recent times, the myth
is well-known as the basis for the popular 1991 video game
Lemmings, in which the player must
stop the lemmings from mindlessly marching over cliffs or into
traps.
A
Canadian Broadcasting
Corporation documentary, Cruel Camera, found that the
lemmings used for White Wilderness were flown from
Hudson
Bay
to Calgary
, Alberta
, Canada,
where they did not jump off the cliff, but in fact were launched
off the cliff using a turntable.
Due to their association with this odd behavior, lemming suicide is
a frequently-used
metaphor in reference to
people who go along unquestioningly with popular opinion, with
potentially dangerous or fatal consequences. This metaphor is seen
many times in popular culture, such as in the video game
Lemmings, and in
episodes of
Red Dwarf and
Adult Swim's show
Robot
Chicken. In
Urban Terror, falling
to one's death is called
doing the lemming thing.
Classification
References
- (Turchin & Ellner, 1997)
- Hinterland Who's Who - Lemmings
- Predators drive the lemming cycle in
Greenland
- ABC.net.au - Lemmings Suicide Myth
- Museum Wormianum seu historia rerum rariorum Ole Worm
(1655)
- Lemming Suicide Myth Disney Film Faked Bogus
Behavior
- Lemming video at Britannica Online
- Blum, Geoffrey. 1996. "One Billion of Something," in: Uncle
Scrooge Adventures by Carl Barks, #9
- snopes.com: White Wilderness Lemmings
Suicide
- Cruel Camera, Time slice: 14:01-15:27
External links
- article by Nils Christian Stenseth on the population cycles of
lemmings and other northern rodents.
- Article about Collared Lemming, see also the main page on
Alaskan mammals
- Rebuttal of lemming suicide:
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