Snow Bunting

Snow bunting

Plectrophenax nivalis

By Ted Brewer

This story is featured in Montana Outdoors November-December 2012 issue

If ever a bird represents cold temperatures, it’s the snow bunting, a winter visitor to Montana from the far north. There’s the name, appropriate for the bright white plumage both males and females wear during breeding season. And there’s the fact that the best chance of seeing these birds in Montana is after a snowstorm, along a roadside where the birds feed on exposed weed and grass seeds unavailable in the buried fields. What’s more, snow buntings thrive in frigid conditions, playing and singing even while winter storms rage around them in temperatures of -25 F or lower.

There’s also this tidbit: Most of the snow bunting’s breeding grounds lie above the Arctic Circle. No songbird breeds as far north as the snow bunting.

Males journey from Montana back to their breeding grounds on the tundra in late winter, when nighttime temperatures in the Arctic still drop down to -20 degrees (females follow four to six weeks later). Males migrate early to establish and defend territories that hold promising nesting sites. To keep warm, males burrow into the snow. They also roost and forage together in flocks of up to 80 individuals.

The cold is also no object when it comes to choosing nest sites. Nests are constructed in deep crevices within rocks—places safe from predators but chilly. To keep the clutch of two to seven eggs warm, the female lines the nest with fur and feathers and rarely leaves. The male forages for insects, then feeds the female on the nest, just as both sexes will later feed the nestlings.

Snow buntings are medium-sized songbirds of the longspur family, roughly 7 inches long with a wingspan of 14 inches. Though not completely lacking darker colors, they show the most white of any similar-sized bird living in Montana, making them easy to identify.

Unfortunately, we in Montana don’t get to see their glorious breeding plumage. When snow buntings are here, pale ginger tips, acquired during the fall molt, veil the pure-white feathers that cover most of their body. During winter, the male bunting rubs these dark outer tips across the snow, wearing them down. By breeding season, he is again sporting his brilliant white plumage, made all the more striking by the streaks of jet black running down his back and across his wingtips. The female at this time looks similar, though her head is white with dark streaks while his is pure white.

With a few minor exceptions, the male and female have indistinguishable plumage color before and after the breeding season, from March through August.

Like other buntings and longspurs, the snow bunting has an elongated hind claw.

Renowned Dutch ornithologist Nikolaas Tinbergen named one of the snow bunting’s defense tactics the “song-fight.” The male flutters up steeply, then sails down in the direction of the intruder, body curved upward, wings trembling in a horizontal position, all the while singing at the top of his lungs. The trespassing snow bunting male usually flees, though ornithologists have witnessed fights in which combatants locked feet and bills and tumbled across snow and rocks.

Throughout their range in the Arctic and Montana, snow buntings are common and widespread, though numbers vary greatly from year to year in any one area. Because snow buntings need snow and cold, our increasingly warmer winters are the species’ primary long-term threat.Bear bullet

Ted Brewer is a writer in Helena.