Conservation Guardians of Northwest Illinois

More Field Notes Previous Next

Home  •  Field Notes  • Snow Birds

Snow Birds

Winter 2003-2004 Newsletter

Now that the winter winds have begun to howl, many folks head south or southwest. These “snow birds” are seeking warmth. The real snow birds are of the avian variety. Triggered by food shortages farther north, several species arrive in our area to survive the winter.

This sudden increase in an animal population is not a true migration; rather, it is called an invasion or irruption. Periodic scarcities of pine seeds, for example, cause Crossbills, Pine Siskins, and other species to wander great distances.

One of our more spectacular winter visitors is the Snowy Owl. This large white-to-greyish owl usually feeds on lemmings in the Arctic. The lemming population declines about every four years, and then the Snowy Owl ranges as far south as Northwest Illinois, seeking rodents, birds, rabbits, and squirrels.

Look for them on power poles, on hay bales, or along the shoreline. The Great Gray Owl is another rarity from the North.

Two familiar winter visitors that we can count on every year are the Dark-eyed Junco and the American Tree Sparrow. The Junco is dark gray with white under parts and the Tree Sparrow has a brown, partially streaked upper body and a clear breast with a brown spot.

Both these species are attracted to bird feeders where they forage on the ground. They also gather along gravel roadsides, eating grit to aid in digestion.

Enjoy these hardy inhabitants of the Far North as they brighten our winter landscape. Come March or early April, they will head north once again.