A well-constructed brush pile should last five or six years, though over time it will collapse under its own weight. To extend the life of the pile add to it every year as materials become available. When the pile becomes simply a mass of organic matter, build a new one right next to the old one. If you live in a rural area and have access to some acreage, build a series of brush piles about 20 yards apart to create even more habitat.
The success of a brush pile can be evaluated by simple observation. After a significant snowfall, which makes brush piles look like igloos, watch them whenever possible. When predators patrol the area, you'll see birds and mammals dash inside to escape danger.
In the morning shortly after daybreak, watch for birds leaving the brush pile. The blanket of snow that covers the pile provides insulation from frigid night air and makes it an ideal roosting site. In late afternoon, watch as these same birds return to the protection of the brush pile to roost. Birds that roost in brush piles include song sparrows, house finches, juncos, white-throated sparrows, and towhees.
The best way to evaluate how mammals use a brush pile is to inspect the perimeter each morning, especially after a snow. Look for tracks of everything from small mammals such as shrews, deer mice, and weasels to skunks, raccoons and opossums.
A trip to the local library should yield some excellent guides to tracking, including "Field Guide to Tracking Animals in Snow" by Louise Forrest and Denise Casey (1988, Stackpole Books, $19.95), "Tracking and the Art of Seeing: How to Read Animal Tracks and Sign" by Paul Rezendes (1999, Collins, $25), and "Mammal Tracks & Sign: A Guide to North American Species" by Mark Elbroch (2003, Stackpole Books. $46.95). Used copies at discounted prices are available at www.amazon.com.
Send questions and comments to Dr. Scott Shalaway, 2222 Fish Ridge Road, Cameron, WV 26033 or by email at sshala...@aol.com