Consider: A new bird report from the National Audubon Society shows that populations of some of America's most “familiar and beloved birds” have taken a precipitous fall over the past four decades, with some down as much as 80 percent. On the list are northern bobwhites, red-headed woodpeckers, northern pintail ducks and Eastern meadowlarks, among many other birds that once boasted healthy populations.

The dramatic declines are caused by the loss of grasslands, healthy forests and wetlands and other critical habitats from multiple environmental threats: urban sprawl, energy development and the spread of industrialized agriculture, according to the report.

“Direct habitat loss continues to be a leading cause for concern,” said Audubon Bird Conservation Director and analysis author, Dr. Greg Butcher. “But now we're seeing the added impact of large-scale environmental problems and policies.”

Grassland bird species have been declining for years. That's not a big surprise, nor should it be to the Audubon Society or any other conservation group. Still, for those who love to see birds at their bird feeders, or for those who are active in the fine art of spying birds in the field, the American landscape has seen better days.

Dr. Butcher says that global warming “is damaging some key habitats and speeding the spread of invasive species” that many scientists believe could spur further bird declines. Mounting demand for corn-based fuels is expected to result in increased use of marginal farmland that currently serves as important habitat.

On the latter point, demand for ethanol across the Great Plains (and beyond) is already causing land-use shifts into environmentally sensitive areas, a disturbing trend that most conservation officials say will continue for the foreseeable future. With corn at roughly $4 a bushel, farmers are cashing in, and it is tough to blame them, for they're simply heeding national policy set by President Bush and lawmakers from both major political parties.