November 14, 2007
By Susan Benson
Director of Education
Cable Natural History Museum
The snow buntings have arrived. You may have noticed the flocks of “little brown birds” along road shoulders and in open fields that are more white than brown. They are hard to see when they are on the ground, but when the flock takes flight, it looks as if a tuft of snow has blown up in the wind.
Snow buntings (Plectrophenax nivalis) are common winter visitors to the northern United States and the higher elevations of northern Colorado and Utah. They come to us from above the Arctic Circle, where they are found in Alaska, across northern Canada, Greenland, Iceland, and very northern Eurasia. They nest on tundra, rocky coastlines, and in the crevices and cracks of rocky mountain slopes. When they are here, we find them feeding on the seeds of grasses and other plants along roads, in fields, and along lakeshores, places most like the open tundra they are accustomed to further north. They are usually seen in flocks, often mixed with other winter birds such as horned larks.
Snow buntings are well-named. The species name nivalis comes from the Latin word, nivis, meaning “snow.” Adults have pure white heads, breasts, and bellies. Over the rest of the body, white is broken up by black on the back, shoulders, wing tips, and tail during the breeding season. Some of this coloration is retained over the winter, but when we see them here, the black has given way to more white on the back and tail along with some light tan on the head and back. Still, the white coloration is very striking, making this little bird difficult to confuse with any of the other winter finches.
Snow buntings are also well-named because, in our region, they portend the arrival of snow. Usually, when the snow buntings arrive, we see snow mixed with the rain or blowing in the cold north wind within a week. This year, just three days passed between my first sighting of the buntings and the first falling of snow. This is in contrast to the Koyukon people of northwestern Alaska who regard snow buntings as a sign of spring, “the certain proof that winter is vanquished at last,” according to writer and anthropologist Richard Nelson. But even in that far land, snow buntings are only visitors that “twitter over the drifts in April and vanish to places farther north a few weeks after [they] appear.”
How do such small birds survive in a bitterly cold place like the Arctic tundra? In her book, For the Birds, Laura Erickson writes that snow buntings can easily survive temperatures of 40 degrees below zero. But during periods of severe cold, the snow bunting, like the ruffed grouse, will stay warm by diving into a snow bank and burrowing in. Also, the black feathers on its back help the bunting to retain heat from the sun. Think of when you wear a black shirt on a sunny day. The black color absorbs light and heat, keeping you warmer than if you were wearing a lighter-colored shirt. Throughout the winter, buntings will use their bills to preen their feathers and they will “snow-bathe” flapping and rubbing in the snow. This actually causes the white and tan colors on their feathers to wear off, exposing the black feathers beneath. By spring, when they head north, the snow bunting is once again brilliantly black and white.
Snow buntings are just one of the winter visitors to our region. Others include the horned lark, common redpoll, pine siskin, and bohemian waxwing (the larger cousin of our resident cedar waxwing). Other, larger birds such as owls attract more attention, but the smaller snow bunting is one of the first to arrive, a special category for a beautiful little bird.
Nature Watch is brought to you by the Cable Natural History Museum. For 40 years, the Museum has served as a guide and mentor to generations of visitors and residents interested in learning to better appreciate and care for the extraordinary natural resources of the region. The Museum invites you to visit its facility in Cable at 43570 Kavanaugh Street or on the web at www.cablemuseum.org to learn more about exhibits and programs.