One of the most functional and attractive features in your house is deadly to birds. We're talking about windows.
Birds simply don't see glass. Instead, they collide with a reflected world. And most birds do not survive the collision.
In fact, windows are so lethal to birds that only habitat destruction kills more of them.
Over the years, our windows have proved fatal to chickadees, doves, sapsuckers, woodpeckers, finches, various warblers, a courting pair of scarlet tanagers, and one ruffed grouse.
If you feed birds, you're probably familiar with the muted thump of a small body colliding with a sheet of glass. Some birds fall dead on impact and may be scavenged before you even find them. Other birds fly away from the collision to die later of brain injuries.
I've moved feeders from one place in the yard to another, hoping to create flight patterns that would lessen the chance of collision.
We've put those hawk silhouettes on the window glass, with the idea that birds will try to avoid predators. We've tied pine cones to strings and hung them in front of the glass.
Bump. Thump. More dead birds.
Daniel Klem Jr., who teaches biology at Muhlenberg College in Pennsylvania, has studied the problem for more than 30 years. He reports that 200-plus species of North American birds are vulnerable to glass collisions.
His single most important recommendation for reducing the death toll: Move your feeders as close as possible to the window(s) they are near. Close means within 3 feet.
We've done this with two small feeders that are attached to our patio doors with suction cups. Birds fly to the feeders, not into the glass. They can hardly collide with the glass when departing.
The added benefit for us is a close-up view of birds feeding, just inches away.
Give them space
Positioning feeders far from windows is another way to reduce collisions.
We've done this, too; our yard feeders are now at least 40 feet from the house. We've situated the feeders near trees and shrubs, which offer protective cover to birds, and help create flight patterns away from the house.
As for hawk silhouettes, Klem scorns them. "They do not work," he said simply.
We followed his advice, sort of. We replaced our window hawks with small (3-inch) translucent decals in the shape of leaves. We use two or three on each pane. They don't compromise our view, but do seem to alert the birds to the windows.
We still find little patches of feathers sticking to the glass as evidence of collisions. But we have fewer of them than we used to.
Feeders put us in closer contact with birds. I think that's good, because we protect what we understand and appreciate. In the long run, the benefit exceeds the cost.
Jim Williams, a member of the American Birding Association, Ducks Unlimited, Pheasants Forever and Delta Waterfowl, can be reached at email@example.com. Join his conversation about birds at www.startribune.com/wingnut.