Northland Nature: Unlike mosquitoes, winter crane flies don’t bite

The second half of November has given us more cold and snow than expected. It has been several years since we’ve entered December with as much of a snow cover as we now have.

Even though early snowfalls happened before the ground and water surfaces froze, the subsequent chill allowed these substrates to freeze — and the snow has remained.

This white blanket has stalled the thickening of lake ice, causing for slush in many of these wetlands. Otherwise, conditions are good for those participating in winter recreation (and at an earlier date than the last few years).

I find that the early snows have opened up other activities as well. Bird feeding is presently being done in earnest; each day I watch as about 10 species — along with a plethora of gray and red squirrels in the daylight, flying squirrels after dark — come by for cold-weather snacks.

Though many of the same kinds appear every day, there are dynamic changes that take place here. What I saw this week differs from last week. Such patterns will probably continue until the deep cold sets in.

Also, this is a terrific time to see animal tracks.

Early-season snowfalls provide the best of several conditions: The snows are not too deep; the weather not too cold; and the texture is often just right to allow for clear footprints and gait. Many of the track makers are active at night and usually not seen, but each morning I can step out to read nocturnal news that tells of what critters have been here — even if I did not see them.

Snowy messages have recently been left by ermines, pine martens, shrews, snowshoe hares and even a sleepless bear. Not one of these wanderers did I see.

While observing the prints on a mild day last week, I noticed more on the snow. Temperatures were in the 20-30 degree range and winds were calm.

As I looked at this crystalline covering, I saw movement. Getting down near it, I saw an insect that at first glance superficially resembled a mosquito. Minnesota is proud of its mosquitoes, and we frequently do see them around us, but not in the snow. I took a closer look: wings like a mosquito, but with no proboscis (mouth tube). The insect was identified as a winter crane fly (pictured). It sat on the snow as though that is where it was supposed to be.

Moving on, I saw that some of these insects were flying. Later I also saw another crane fly and three kinds of spiders on the snow.

A little research determined that a few species of crane flies reach maturity in winter, and, even though their lifetimes are a bit abbreviated since they do not have mouth parts (thus no feeding), they remain active in the chilly times, mating and laying eggs.

Some may be seen during winter days that are near freezing, but they are most common early in the season. I have often noted their movements over the snow, walking or flying, in early December — before the deep cold settles in. When needing shelter, they’ll go behind loose bark or get under the snowpack, where subsurface space is warmer.

During our outdoor activities in the next few weeks, if you think that you’ve just seen an insect on the snow or one fly by, you probably did. You may have just seen winter crane flies, not mosquitoes, and they are not going to bite.