Mike Jacobs: Phantom species flit in from the North
The snow bunting is as much a sign of changing seasons as the robin, but perhaps not so welcome. The robin announces spring, while the bunting arrives with the snow. With us it is a winter bird. It is the same for most Canadians, most Icelanders, most Scandinavians, most Finns and most Russians, in fact for almost all humans who live south of the Arctic Circle.
The snow bunting breeds farther north than any other land bird, so far north that the limits of its range aren't known precisely — suggesting that snow buntings occur wherever nesting sites are available and the food supply is adequate to raise a brood. Those conditions vary from year to year.
The bird's winter range is known more clearly, but it varies considerably, too. Wintering snow buntings are nomads. In common with many other northern species, their appearance is somewhat erratic.
These exigencies contribute to the snow bird's reputation as a kind of phantom, sometimes present and sometimes not. Appearance and behavior add to this impression.
As birds of open country, snow buntings often occur on roadsides and in fallow fields. However bleak these appear to human observers, they appeal to buntings, perhaps because they are reminiscent of their home ranges — but more likely because they offer opportunities to glean seeds, the buntings' major food source.
Snow buntings are predominately white with black on the wings and tail. In winter, the birds acquire some rust in the plumage. White is the dominant color, though. Snow buntings that flush along a roadside appear white to a passing motorist. Sunlight accentuates the brilliant white of snowbirds, and a flock in flight can appear as a dazzling wave of white. The wave is ephemeral, however; as the flock wheels, the impression vanishes, phantomlike.
This happens with flocks of buntings feeding in a field, as well. The birds at the back of the flock rise and move to the front. This creates the impression of a loose mass rolling across the landscape. Sunlight increases the effect.
In general, snow buntings are ground-loving birds. They don't often perch very far above ground level. A group of snow buntings in a brush patch or a clump of thistles leaves its own magical impression, of startling white ornaments on a bare branch.
Snow buntings occur in smaller groups, as well, most often at the onset of migration in both fall and spring. The first snow buntings appeared along Grand Forks County Road 33 in early October, just ahead of the first snow — early for both snow and snow buntings, I thought. The birds were probably not an omen of impending snowfall; rather, they were responding to existing conditions, including the decrease in daylight in their nesting range.
County Road 33 is our usual route to Grand Forks from our place west of Gilby, N.D. The road passes bare fields and grasslands, a combination attractive to snow buntings. It also carries a lot of trucks, which spill grain along the road margin.
Like almost any rural road in the Red River Valley, that's perfect from the point of view of a snow bunting.
From a human point of view, however, it seems a hard way to make a living.
Foraging in winter in the Red River Valley is not the greatest challenge facing snow buntings, however. Conditions in the Far North are even more challenging. The birds need sheltered spots in which to nest. On the Arctic tundra, these are in short supply, and crevasses in rock ledges are at a premium, because they cut the wind and foil the predators.
Competition for these sites is intense, and male snow buntings start moving north in March in order to secure the best of them. Their departure goes unnoticed for the most part. Female buntings stick around for perhaps a month, so the number of buntings decreases but their presence is still noticeable.
To humans, the disappearance of something is less noticeable than its appearance, and even conspicuous backyard birds manage to slip away when their migration — southward in this case — begins.
The snow bunting is a circumpolar species occurring in high latitudes around the world. Populations are mostly migratory and occur as far south as northern Texas and the Delmarva Peninsula, where they forage along Atlantic Ocean beaches.
Another bird species is a kind of doppelganger. This is McKay's bunting, a species restricted to islands in the Bering Sea. Apparently, a small population of buntings remained behind as ocean levels rose at the end of the last Ice Age, and interbreeding led to the emergence of a new species.
Probably, snow buntings themselves nested along the front, or southern, edge of the glacial mass — raising the intriguing possibility that they were once summer birds in our area.