Snowy Owls and Lemmings
There is an irruption of snowy owls going on in the United States this winter. They are showing up in unusually large numbers in the northeast and mid-Atlantic states as well as in the Midwest. For example, they are making the news for showing up in around the shore on Lake Michigan in the Chicago area and have even been sighted as far south as South Carolina. Although I have not heard about an unusually large number of sightings in North Dakota yet, we will probably be in for a great winter of owl watching. So be on the lookout!
Snowy owls are species of the tundra but a few of them seem to show up in North Dakota most winters. However, this interesting species is known for their occasional invasions or irruptions in areas south of their normal wintering range when the populations of lemmings, their principle prey, are down. Lemmings are those small mouse-like mammals of the tundra that are known for their wide population fluctuations.
Lemming populations are cyclic on 3-4 year intervals. These cycles are not well understood, but may be related to food availability, predation, and or other factors. It is a common misconception that when the lemming population reaches some critical density, some internal mechanism kicks-in, resulting in mass suicide, complete with lemmings jumping of cliffs into the ocean and the like. That is pure fiction, and seems to have originated with the 1950’s Walt Disney movie Wild Wilderness. Large numbers of lemmings were shown jumping off a cliff near the ocean, in what seemed an obviously bizarre mass suicide, when in fact the animals were collected and released in a small area and herded off the cliff, assumedly for dramatic effect.
Some of you may recall that we had an irruption of snowy owls in the region during the winter of 2011-2012. That irruption was different in that the owls came southward, not because of a food shortage, but because of an unusually successful breeding season. Snowy owls are territorial, and apparently all those young owls (mostly males) could not find suitable territories closer to home and so wandered southward.
So be on the lookout for these magnificent birds perching on utility poles, fence posts as well as on the ground this winter. There is something quite interesting and exotic to this occasional arctic visitor.
Natural North Dakota is supported by NDSU Central Grasslands Research Extension Center and Minot State University-Bottineau, and by the members of Prairie Public. Thanks to Sunny 101.9 in Bottineau for their recording services.