Lemmings are on the move. Particularly when night falls, there are dozens, even hundreds of them scurrying about on roads and yards in the northernmost parts of Finland. We have waited for the lemming migration for more than 30 years, and now it’s here. It began in the spring, and after a quiet summer, they are becoming more active again. In Finland, the last great migration took place in 1969–70. Now it’s possible to watch nature’s drama both in the wild and in people’s own yards.
In reality, the lemming migration is not what you see in Walt Disney movies, where they move in great masses, but there are so many of them that it is rare to see such hustle and bustle in the Finnish wilds. With all the lemmings and millions of voles, birds of prey and mammals are also doing well. People wondered why there were so few birds of prey in early summer, but the reason is obvious: it was so easy to catch food that the mother birds caught all they needed for themselves and their families in the morning and could sit on a branch digesting it for the rest of the day. Now you can see owls and hawks again, as the young birds have spread their wings and are filling up with food for the winter and migration. Even the endangered snowy owl has nested in Finland after a break of several years.
Report sightings
The Finnish Association for Nature Conservation, together with Metsähallitus Natural Heritage Services, has been gathering information on the distribution of lemmings all summer. Anyone can report their sightings at www.sll.fi (in Finnish) and see how the migration is progressing. There are currently more than 10,000 lemming sightings, and the figure is growing steadily. The lemmings’ adventures have also been recorded on video throughout the summer, and you can find very nice clips in the social media!
Strategic background
The Norway lemming is well adapted to arctic conditions. Dramatic changes in the size of its population are common, similar to voles and many other mammals. Lemmings live peacefully in their home fells, caring for their young, until there are so many of them that they are forced to move to lower slopes in search of food. When they find food, they stop to feed and breed. The population increases quickly. Five to seven young are born every three weeks. They reach sexual maturity at about five weeks of age and start their own family.
Large numbers cause distress
As their number grows, the lemmings begin to bump into one another. Distressed lemmings become angry and lash out at other lemmings – and eventually at anything that moves. The migrants have no clear common destination. They are heading for a new feeding ground, but its location is probably a mystery to these little creatures. In the end, those who survive do so mainly because of chance.
A quiet, snowy world
The life of a lemming quietens down when winter comes. They do well under dry powder snow, but wet snow freezes the feeding grounds and nest holes in the shrubs, making it hard to survive the winter. If the upcoming winter is as good as the last one, there will still be plenty of lemmings next spring. However, if you want to be sure of seeing lemmings with your own eyes, you should head north this very autumn. At the moment, most lemming sightings are made north of the Kolari–Sodankylä line and the best places for sightings are in northernmost Lapland. Observation is easy, as you do not necessarily need to go into the wild. Even those who like to stay close to civilization can observe lemmings from, say, a restaurant terrace. The best time for sightings continues well into the night!