Bird of the Week

This week’s Bird of the Week, compliments of the Weminuche Audubon Society and Audubon Rockies, is the American tree sparrow. European settlers in North America, reminded of a bird on the continent they left behind, gave the American tree sparrow a name that really doesn’t fit. Instead of in trees, these birds are more likely found on the ground, where, in winter, they search for food in weedy fields, brushy edges of woodlands, crop fields and overgrown gardens. Even their breeding areas in far northern tundras are scrubby areas at or above the northern treeline, and usually have only a few small trees used by males to perch and sing their sweet songs. These regions, which stretch across Alaska and northern Canada, provide the abundant supply of insects, spiders and snails which birds eat and feed to their young during breeding season. In winter, American tree sparrows range across northern and central North America. From fall through spring their diet is almost exclusively vegetarian. In small flocks they scratch and peck at the ground, hop up at bent weeds and fly up and beat their wings against grass heads to dislodge seeds. Flocks communicate with musical two-note calls while foraging. Where they live around people, they readily eat seeds under bird feeders. These sparrows need to take in around 30 percent of their body weight and a similar proportion of water each day to survive. Comparing to a human, this would mean a person weighing 150 pounds would daily need to take in 45 pounds of food and five gallons of water. American tree sparrows are identified by a rust-colored cap and eyeline, plain gray chest with a central smudge spot and bi-colored bills, dark on top and yellow on bottom. They are known as “winter chippies,” a nod to the similarities shared with chipping sparrows, a common summer sparrow that migrates south in winter. Due to troubling long-term population trends, Partners in Flight lists these birds in the category of Common Birds in Steep Decline. The loss of weedy field habitats in their winter range is thought to be a contributing factor. For information on events, visit www.weminucheaudubon.org and www.facebook.com/weminucheaudubon/.