Distinctly Montana Magazine

D I S T I N C T L Y M O N T A N A M A G A Z I N E • W I N T E R 2 0 2 0 18 ered), and with enough density to rival the insulation of an Arctic fox. It also has an insurance policy. is owl can go 22 to 40 days without food, possibly related to its thick layer of fat. One more predator comes from the north, the northern shrike. is songbird also wears a hooked bill and zeroes in on voles. If snow deepens enough to hide the voles, northern shrikes will switch to hunting for small songbirds. ey have another fallback, too. When prey is plentiful, they hang their kill over a branch, building a larder for times of scarcity. Surprisingly, its song, which mimics others and increases in late spring, attracts songbirds. It may be a handy lure just as the rodent supply weakens. Undue depth of snow does not cover only prey. It also covers the seed-eater's food. American tree sparrows, which forage on the ground, have a solution for that. ey beat at grasses with seedheads above the snow, dropping seeds to the white surface. When snowfall rises above seedhead level, the sparrows turn to bird feeders or wander to less snowy areas. Open country where grass and weeds poke out of the snow works best for this sparrow, which winters farther north than any other, including much of Alberta. On occasion it takes refuge under the snow, roosting together with others of its kind. At the low end of the temperature spectrum, research shows this hardy sparrow can handle subzero temperatures, provided it consumes enough calories. Its usual daily diet of seeds amounts to 30 percent of its weight. e entire population of American tree sparrows evacuates its breed- ing grounds for the winter, but the even hardier common redpoll leaves some of its kind to winter on the breeding grounds. Like the snowy owl, the wintering redpolls fan out all the way from the Arctic to just over the Montana border in normal years. In irruption years, roughly every other year, they cover the state. e common redpoll, so much smaller than a snowy owl, has a tall order when it comes to keeping warm. Like the owl, this finch has extra feathering (31 percent more feathers by weight in November compared to July) and extra fat (50 percent more than they do in summer). It can also feed at night. In addition, this small bird that winters in the Arctic interior has a sizeable throat pouch to store the birch seed it eats— a handy pocket for a midnight snack, and a way to carry seed to its snow tunnel for husking, sparing it from more time in the elements. e redpoll also roosts and sleeps in the tunnel. As for the hoary redpoll, this scarce species differs only subtly from the common redpoll in just about all respects. Even in an irruption year, only a few are reported in Montana, where together with common red- polls, they linger around brush, weedy fields, and backyard feeders. Common redpoll Rough legged hawk STEVE AKRE LIZ LARCOM

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