A Fatal Attraction

Nov. 13, 2006 — -- Bird-watching is a classic American pastime; over $30 billion a year is spent on the hobby. We love to watch birds when they are in our backyards -- their native habitats -- but few of us realize the dangers the birds face during their seasonal migrations.

Between 100 million and one billion birds are killed every year in the United States when they crash into glass windows. And even one billion deaths might be a conservative estimate, says ornithologist Daniel Klem Jr. of Muhlenberg College in Allentown, Pa.

At that upper estimate, it would take approximately 3,000 Exxon Valdez oil spills to match one year's death toll due to glass collisions, says Klem, who has studied the causes of bird fatalities for more than 30 years.

And until recently, he says, the conservation community has not paid attention to the problem "because there's no easy solution."

"There are billions of dollars spent on bird watching," Klem told ABC News. "Acquaintances that I know that are so avid and so knowledgeable about birding -- they're totally clueless about this. It's like our populations are bleeding away, and they're not able to be replenished."

Most of the fatalities come during the spring and fall migrations, when billions of birds cross the country as they travel great distances -- sometimes as far as from Central America to Canada.

The problem is that the glass in buildings is as invisible to birds as it is to people. "By day, birds see sky, clouds and trees reflected in glass facades and they 'think' that they can fly into it," explains industrial ornithologist Richard Podolsky.

"And by night, especially foggy nights when the top of the Empire State Building is draped in fog, birds fixate on lights and fly towards them or around them and crash into buildings."

"We now are building these all-glass buildings everywhere," said New York architect Bruce Fowle. By adding more trees to our cities, says Fowle, "We're enhancing the bird habitat ... At the same time we're creating these killers."

Dr. Podolsky has been advising the developers of New York's 1,776-foot Freedom Tower, which will be built on the site of the World Trade Center and will incorporate innovative designs to reduce bird deaths.