Friday, November 27, 2009
American Tree Sparrows
I opened my blinds to a fresh sunny morning after several consecutive days of gray skies and rain. Though I've not been to the prairie in a few weeks, I plan on making a visit sometime this weekend. Now the tan and russet fields of Pheasant Branch are decorated with American Tree Sparrows. They'll conspicuously perch and feed atop "dead" goldenrod and other wildflowers. These particular sparrows won't return to Canada until March - there's plenty of food here to sustain them through the winter (but the diminutive birds are also food to shrikes and kestrels).
The cold weather they deserted in September is slowly catching up with them, and soon much of their quarry will be buried beneath snow. Out of curiosity, I've visited the prairie during blizzard conditions and witnessed the hearty sparrows at work. Surprisingly, the foraging flocks are a little tighter despite the wind. If a few take off, the rest immediately follow. If they can manage, they'll still perch on tall plants, but under extremely harsh conditions they tend to feed around fallen stalks within reach of the snow-covered ground.
A snowstorm in December or January might last the remainder of the day and duration of the night, whereupon the weary birds are likely to roost communally in snow cavities. With a storm ending before first light, their familiar tweedle tweedle calls can be heard all across the prairie by morning. Quickly replenishing their energy is critical for survival as they endure subzero temperatures 24 hours a day during cold snaps lasting a week or longer. The American Tree Sparrows that come to your backyard feeders certainly have it easier, so my respect and admiration goes to those facing winter the old fashioned way.
© 2009 Mike McDowell
Posted by Mike McDowell at 2:38 PM