Lemming
Lemming Facts
Size | 3-6 inches (8-15 cm) |
Speed | Up to 3 mph (5 km/h) |
Weight | 1.4-5.2 ounces (40-150 grams) |
Lifespan | 1-2 years |
Food | Moss, grasses, berries, herbs |
Predators | Owls, foxes, wolves, weasels, ermines |
Habitat | Northern Europe, Asia, North America |
Order | Rodents |
Family | Cricetidae |
Scientific name | Lemmus |
Characteristics | Small rodent, reproduces quickly, lives under the snow in winter |
Main Characteristics
Lemmings are small rodents known for their rapid reproduction. When their population becomes too large in one area, they migrate in search of new habitats. They're closely related to mice.
Species
Lemmings are part of the arvicolinae family, which also includes voles and muskrats. There are several species, including the Norway lemming, the West Siberian lemming, the Canadian brown lemming, and the collared lemming.
Distribution and Habitat
Lemmings can be found in Norway, Siberia, Asia, northern Canada, and Alaska. They thrive in the Arctic tundra environment.
Way of Life
Lemmings are active both day and night, only taking a quick nap when they're tired. When they're not foraging for food, they hide in their burrows underground, where they are safe from predators and the cold. While they are generally solitary creatures, they come together in large groups when searching for a new habitat or a mate. It's a common myth that they collectively leap off cliffs, but that's not true.
Anatomy and Appearance
Size and Weight
Lemmings measure 3-6 inches (8-15 cm) in body length, with tails being 0.4-0.8 inches (1-2 cm) long. Their weight ranges from 1.4-5.2 ounces (40-150 grams).
Coat
Lemmings have a waterproof coat that is typically gray or brown. However, the Norway lemming stands out with its striking, multicolored fur, featuring shades of light brown, reddish-brown, and dark brown. Interestingly, the collared lemming is unique in that it changes its fur color in winter, turning completely white.
Teeth and Claws
Lemmings have really sharp teeth and claws. They help them cut grass, moss, and leaves or pull them out from tiny cracks in rocks.
Lemming or Hamster – What's the Difference?
The Norway lemming looks a lot like the European hamster. Are they related? Yes, they are both part of the cricetidae family, but they belong to different subfamilies. European hamsters are at least twice as big and weigh double as much. Their ears are much larger too. There are more differences: hamsters don’t eat grasses and moss but grain. They live in fields, gardens, and meadows, not in the tundra. Their behavior is different as well. When hamsters feel threatened, they run away, while lemmings will defend themselves.
Diet
Lemmings are herbivores. They eat grass, moss, leaves, buds, bark, twigs, and seeds.
Adataptions to the Habitat
Surviving in the Arctic tundra is quite a challenge. The temperatures are extremely low, and food is scarce. Lemmings have made remarkable adaptations:
Small Ears and Short Legs
Lemmings have very small ears and short legs, which help them retain warmth more effectively.
Camouflage in the Snow
In winter, collared lemmings change their color from brown to white. They venture out of their burrows more often during this season and are perfectly camouflaged with their white fur.
Insulating Winter Coat
In winter, lemmings grow a thick, insulating coat that keeps them warm.
Winter Claws
The collared lemming develops "winter claws" on its third and fourth toes during the winter. These claws are longer than those in summer and resemble small shovels, aiding them in digging for food in the snow.
Behavior
Burrow Construction
Lemmings build cozy burrows, lining them with soft materials like wool, grass, and feathers to enhance their comfort.
Hibernation
Lemmings don't hibernate. Their underground burrows remain frost-free, allowing them to stay active during the cold winter months. They only leave their burrow to search for food.
Sounds
Lemmings emit high-pitched squeals to deter potential threats.
Defense
Lemmings are known for their aggressive nature and remarkable bravery. When threatened by predators, they scream and bite to ward them off.
Migrations
Due to Overcrowding
Lemmings experience a massive population boom every four years. This leads to them living in very close quarters, which can be quite bothersome since they are solitary creatures. As a result, they set off in search of more food and space and thousands of them march across the tundra.
Obstacles
These migrations are incredibly exhausting, and many lemmings unfortunately starve along the way. Occasionally, they encounter obstacles, such as a lake. While they are adept at swimming, sometimes the lake is simply too vast or the river too turbulent. Consequently, many of them drown. Once they reach a new home, the surviving lemmings quickly reproduce again.
Abilities and Senses
Swimming
During their journeys, lemmings often need to cross small stretches of water. Fortunately, they are excellent swimmers and even have waterproof fur. The widespread myth that they intentionally jump into the water to drown is not true.
The Life Cycle of Lemmings
The "Normal" Cycle
During the Arctic summer, lemmings become prey for arctic foxes, snowy owls, and skuas. When lemming populations are high, these predators have plenty to eat and can reproduce rapidly. However, this leads to an overpopulation of predators and a shortage of lemmings, resulting in many predators starving. In winter, lemmings can then reproduce again, and the cycle starts anew.
Every Four Years, They Reproduce Explosively
Every four years, there is a significant increase in the lemming population. Shortly after, their numbers drop dramatically. This occurs for two main reasons. First, the stoat, unlike other predators, hunts lemmings even in winter. Second, the stoat only has offspring once a year. As a result, it takes four years for the population of hungry stoats to grow large enough to cause a sudden and significant decline in lemming numbers. Thus, the stoat is primarily responsible for their mass die-off.
Life Expectancy
In the wild, lemmings typically live for just 1-2 years.
Predators and Threats
Natural Enemies
Lemmings face numerous predators. They are hunted by Arctic foxes, snowy owls, skuas, stoats, weasels, owls, foxes, and wolves.
Human Impact
Climate change poses the greatest threat to lemmings. The snow in their homes is melting away. At first, it might seem like this is good for them since they won’t be as cold. However, the changes in their environment actually make things harder. Their burrows are less safe because the ground isn’t frozen anymore. They have to stay above ground more often, which puts them at risk from predators and bad weather. Their migrations become more difficult as they have to navigate uneven terrain.
Conservation Status
Lemmings aren't considered an endangered species.
Importance for the Ecosystem
Lemmings play a crucial role in the ecosystem, primarily as prey for a variety of predators. A decline in lemming populations can disrupt the delicate balance of the Arctic tundra.
Reproduction
Lemmings reproduce at a rapid pace. The babies are born after a gestation period of about three weeks, weighing only 0.1 ounces (3 grams) at birth. Initially, they stay in their cozy burrow to avoid freezing during the harsh Arctic winter. They open their eyes after 11 days and start walking by 15 days old. By the time they are 5-6 weeks, they reach maturity and are capable of having offspring. Female lemmings can give birth to young up to eight times in their lifetime, with each litter typically consisting of 5-6 babies.
Lemmings As Pets
When talking about pet lemmings, people are actually referring to the steppe lemming. However, it isn't a true lemming; it belongs to the Lagurini family. Still, the two types are closely related.
Fun Facts
Lemmings Don't Commit Suicide
It is said that lemmings jump off cliffs in droves to commit suicide, a notion that even inspired a video game of the same name. However, this idea is completely false. The blame lies with the Disney film "White Wilderness," where filmmakers allegedly manipulated the footage. Rumor has it that they not only recorded a misleading narration but also staged nearly all the scenes depicting the mass suicide.
Don't Be a Lemming
"Don't be a lemming" is a well-known saying. It means that a person shouldn't just follow what everyone else is doing without thinking for themselves. The saying comes from the mistaken belief that lemmings mindlessly follow each other and jump off cliffs in big groups.
The Lemming Is Related To:
- Hamster
- Mouse
Animals in the Same Biome:
- Arctic Fox
- Arctic Hare
- Beaver
- Black Bear
- Brown Bear
- Musk Ox
- Polar Bear
- Reindeer
- Snowy Owl
- Tiger
- Wolf
Sources:
- „Lemmings“ (https://www.adfg.alaska.gov)
- „On reproduction in lemmings“ (https://www.arlis.org)
- „Lemming facts“ (https://arcticwildlifeknowledge.com)