What's so striking in this morning's story on declining bird species in the U.S.--of 683 species that regularly breed in this country, 178, or 26 percent, are in trouble--is the new culprit on the scene: global warming.

That should have been obvious. If you're a murrelet that breeds and feeds around Alaskan glaciers, as those ice mountains melt of course you're in trouble. And if you're a shorebird like the sharp-tailed sparrow, which lives only in a saltmarshes along the Atlantic and Gulf Coasts, of course as seas rise your home shrinks.

Global warming is also having indirect effects on bird populations. It is altering ocean circulation and the distribution of fish, mollusks and other bird foods, with the result that the Xantus’s murrelet, for instance, which nests on islands off southern California, and other coastal seabirds are imperiled due to food shortages.

As John Flicker, president of the National Audubon Society, put it during a press conference, these birds' fate "is determined by human activities more than anything else. For WatchList birds, the clock is ticking." George Fenwick, president of the American Bird Conservancy (which together with Audubon is issuing the WatchList), went further: "We should not be the generation about whom future Americans ask, 'Why didn't they act?'"