Tuesday, October 2, 2012

Making Our Windows Safe for Birds

Black-and-white Warbler

Before winter descends in earnest, it’s a good idea to check your bird feeding station for potential dangers. It’s a dreadful irony to invite birds in for human enjoyment if the price they pay is injury or even death.

The windows through which we so enjoy watching our winter birds are treacherous deathtraps. Windows kill half a billion to as many as a billion birds in the United States every year. Of birds that hit windows and fly away, studies conclude that a full 50 percent die later from head trauma and other collision-related injuries. Many of these birds aren’t drawn into our yards by feeders: every spring and fall I hear of residential house window mortality by Ovenbirds, cuckoos, and other insectivores that never visit feeders. Some of these were attracted to yards by all the bird activity even though they themselves don’t visit feeders. I’ve been brought dead and injured saw-whet and Boreal Owls that had been drawn to feeding stations not for bird seed but for the birds themselves.

Many window-related deaths take place in cities—birds have to pass through all kinds of habitat in their journeys to the tropics, and many nocturnal migrants are disoriented by lights at skyscraper windows up at the elevations at which the birds are migrating. Several large cities have organizations that work on minimizing those kills by encouraging owners and managers to douse the lights on good migration nights. [See the Fatal Light Awareness Program's website.) But kills at lower windows are just as bad, and trickier for us to deal with. A recent study inEdmonton found that birds are, as one might expect, most likely to be killed in areas where their numbers are most dense—in other words, in rural areas, in established urban areas that have many mature trees, and near bird feeding stations. So whatever we can do to minimize the issues in our yards does make a difference.

Unfortunately, making our windows safe for birds isn’t easy. When you’re installing new windows, double-hung windows with the screens on the outside are the only windows that are actually bird-friendly, at least as long as those screens stay up. You can affix decals or tape to the outside of the glass—including some sold by the American Bird Conservancy—to help birds see the glass, but it’s important to remember that in nature birds easily negotiate flying rapidly between branches. The only way decals or tape work effectively is when you leave no more space between them than a spread hand.

Bird Screening

Setting bird netting on the outside of a window can help, too, though it’s tricky to get it set to be taut enough to work as a trampoline rather than a bird trap. The BirdScreen Company customizes window screening designed to be hung on the outside of windows; creative people can devise similar systems for themselves.

Whether or not you can get up external screening, decals, or tape, set your feeders directly on the glass or window framing. When birds fly off from a feeder set any further than 3 feet away from the window, they can collide at top speed. When we set feeders any further than that while still at a comfortable distance for our viewing pleasure, we are unknowingly setting a deathtrap. One Mother’s Day, my husband and kids built a big platform feeder set into the framing of our dining room window, and since then not a single bird has crashed into what had been a real killer. Now THAT was a gift that keeps on giving.

Pileated Woodpecker