U.S. bird populations plummet
Rhett A. Butler, mongabay.com
June 14, 2007





Populations of some of America's most common birds have plummeted over the past forty years, reports a new analysis by the National Audubon Society. Some species have seen a decline of 80 percent.

The study, which combines the National Audubon Society's Christmas Bird Count with summertime surveys by the U.S. Geological Survey, found California species were particularly affected, with populations declines of 75 to 96 percent for several species, including the Northern Pintail, Horned Lark, and Loggerhead Shrike.

The National Audubon Society attributes the decline to loss of habitat, especially grasslands, forests and wetlands to urban sprawl, energy development, and industrialized agriculture. The group warns that climate change could compound losses in the future.


Evening Grosbeak. Photo by Dave Menke of the U.S. Fish and Wildlife Service

"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 Audubon Chairperson and former EPA Administrator, Carol Browner. "Their decline tells us we have serious work to do, from protecting local habitats to addressing the huge threats from global warming."

All the species on Audubon's list of 20 Common Birds in Decline have seen their populations plummet at least 54 percent since 1967. Nationwide, the hardest hit were the Northern Bobwhite (82 percent decline), Evening Grosbeaks (78 percent), Northern Pintail (78 percent), and Greater Scaup (75 percent). The charismatic Rufous Hummingbird saw its population fall 58 percent.

The National Audubon Society said agricultural and development pressures have driven grassland birds to the worst declines.


Evening Grosbeak. Photo by Howard B. Eskin

"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."

"People who care about the birds and about human quality of life need to get involved in habitat protection at home, in pushing for better state and national protections and in making changes in their daily routines," he added.

The National Audubon Society says habitat protection through sound agricultural policy, sustainable forest use, and wetland conservation is the most important step to protecting bird species. It notes that combating invasive species and reducing global warming emissions and pollution will also help America's bird populations.

A study published earlier this month in PLoS Biology warned that climate change and habitat destruction could cause the extinction of 10-20 percent of terrestrial bird species by 2100. Similar figures were put forth by researchers in a paper published in The Proceedings of the National Academy of Sciences last year.

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CITATION:
Rhett A. Butler, mongabay.com (June 14, 2007).

U.S. bird populations plummet.

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