The average population of these common birds has fallen 68% since 1967; the 20 birds listed on the national "Common Birds in Decline" database (including such perennial favorites as the Common Tern and Field Sparrow) have lost at least half of their populations during that period. Some species, including the once familiar Northern Bobwhite (seen above), have witnessed collapses in their numbers as high as 80%. These numbers were obtained from the Audubon Society's long-running citizen-led Christmas Bird Count and its Breeding Bird Survey.
"The song of Eastern meadowlarks used to be the soundtrack of summer," said Scott Weidensaul, a naturalist and author born in eastern Pennsylvania. "Now it's a rare thing. The landscape is changing. Farming is much more industrialized. Development is sprawling across these valleys."
Much of the blame can be attributed to the usual suspects: reckless human development, pressure from logging, industrialized agriculture and mining. In recent decades, these anthropogenic effects have been greatly amplified by the influence of global warming, which will continue to loom large as a critical threat to the future survival of many of these species even as we begin taking constructive steps towards remedying the situation.
"These are not rare or exotic birds we're talking about—these are the birds that visit our feeders and congregate at nearby lakes and seashores and yet they are disappearing day by day," said Carol Browner, the Audubon chair and former EPA administrator. "Their decline tells us we have serious work to do, from protecting local habitats to addressing the huge threats from global warming."
For tips on how you can help to take on this serious issue, head over to this page.