Windows pose deadly, invisible threat to birds on the wing

By Rich Landers | The (Spokane) Spokesman-Review • Published November 07, 2008

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Picture windows that enable us to enjoy nature from the comfort of our homes can be deadly to the birds we love to watch. And that's putting it mildly.

Ornithologists estimate that in North America alone, 100 million to 1 billion birds a year are killed in collisions with windows or towers, said Laura Erickson, science editor for the Cornell Lab of Ornithology.

That's about twice the carnage caused by free-roaming cats, and maybe a thousand times the toll taken by hunters.

The problem was driven home last weekend when neighbors called me to admire and identify a beautiful young hawk that had met its maker in a large pane of glass above their front door.

With the help of a falconer who weighed the bird at 23 ounces, we were able to rule out the possibility it was a female Cooper's hawk and identify the victim as an immature male goshawk. The predator likely was attracted by the quail at a backyard feeder.

With a twinge of angst, we all admired the hawk, limp and lifeless but still warm and pristine, from its hooked beak to its lavishly feathered thighs. Bare yellow legs and toes were spiked with sharp polished-black talons.

"We've got to do something about our windows," said my neighbor, looking at the expanses of glass around their lovely home. "We have all kinds of birds hitting the windows all the time."

My God, I thought: If I stepped out on my porch with a shotgun and blasted a few songbirds every day, the neighborhood would be rightfully outraged.

But we're all so nonchalant about the passive and indiscriminant killing of birds that collide with our homes.

"We suspect a high percentage of the birds that fly away after a window strike don't make it," Erickson said.

Famed bird artist and guidebook author David Sibley has taken a keen interest in window collisions. Behind habitat loss, windows are a leading human threat to birds even though they may be among the easiest threats to tame.

Taking a scientific approach at the window facing his bird feeders, Sibley's recorded as many as six bird strikes in 1 hour, 40 minutes. His experiments with deterrents can be found on his blog at www.sibleyguides.com.