Winter weather brings winter birds, and that is something to welcome and to wonder at.
Why do the birds come?
How do they find their way?
Bird lovers have puzzled about these questions for generations, and still there is no single, clear and definitive answer.
That bit of mystery enhances the arrival of these wanderers, at least for me. The first snowy owl of the season, for me, appeared Monday afternoon, propelling itself across County Road 33, my usual road to Grand Forks. Its powerful wings drove it quickly southward, perhaps 10 feet above the ground, silent and ghostlike.
Magnificent in every respect.
There is no way to know with certainty whether this bird is the vanguard of an invasion of snowy owls. Their numbers vary from year to year. I once saw more than 60 in a single day within the borders of Grand Forks County. One year, I saw only six in a whole season.
Why should this be?
The usual theory is that owls come south when food is scarce in the Arctic. Lately, however, ornithologists have wondered whether the opposite might be true. Years of plenty spur greater nesting success, and surplus population drifts southward, not because food is scarce but because competition for food is greater and pickings are easier elsewhere.
Or, it might be simple wanderlust. That powerful impulse drives many species to explore the world, ours among them. Of course, want helped drive humans to overrun the planet. And opportunity, as well.
Probably, it’s the same with wild birds.
Snowy owls are not the only northern species that come south in winter. On the afternoon of my owl sighting, I was seldom out of sight of snow buntings, which lifted off the shoulder of the road as I drove along. The buntings undoubtedly were gleaning seeds along the roadside; both spilled grain and weed seeds.
The number of buntings seemed to me to be greater than in other years. The same is true for Lapland longspurs, another northern seed eater.
Perhaps this was a good year for buntings and the population is larger than it has been. Or, could it be that the buntings moved en masse and quickly, rather than at leisure and in smaller groups? The sudden start of winter weather might have spurred them on.
The same may be true for longspurs.
It may be, however, that I haven’t actually seen more longspurs, just recognized more longspurs. In other words, I’ve suddenly acquired the ability to pick them out among the buntings.
Longspurs do form pure flocks, and in that situation, they are easy enough to recognize, if only because there are few other possibilities. Horned larks might be confused with longspurs, but horned larks don’t often occur in such large flocks. Plus, they give themselves away by flashing white feathers as they fly.
Flocks of snow buntings often include a few longspurs but seldom a lot. This complicates identification, especially while driving. A speeding automobile doesn’t permit close examination of fleeing birds.
At rest, however, the longspurs appear plainer than the buntings, grayer or browner, overall, while the buntings show quite a lot of white and rust color and not so much brown. This gives them a lighter, brighter appearance. This is especially obvious when the birds rise and fly ahead, almost seeming to roll across the landscape. Of course, they move too quickly to pick the browner birds out of the mass.
Another northern bird can be expected in open country. This is the rough-legged hawk, which I think of as “November’s hawk.” The rough-legged hawk is a large bird, often seen hovering over grasslands and marshes — landscapes that resemble the bird’s Arctic nesting grounds. No other large hovering hawk occurs here. These hawks usually show sharp contrast between light and dark, though perhaps 10 percent of rough-legged hawks are dark or “melanistic” individuals.
A couple of other northern species have shown up: Pine siskins seem more numerous than usual, and common redpolls arrived early this year. Sightings of northern ravens seem more frequent, too.
A couple of reports of pine grosbeaks have reached me, but so far, no word of evening grosbeaks — one of the most valued sightings locally. These sightings have diminished over the last couple of decades.