Populations of many of the US most commons birds have crashed

Species on Audubon’s list of 20 Common Birds in Decline have seen their populations plummet at least 54 percent since 1967. The following are among those hardest hit:

• Northern Bobwhite populations are down 82 percent and have largely vanished from northern parts of their range in Wisconsin, Michigan, New York and New England mainly due to loss of suitable habitat to development, agricultural expansion and plantation-style forestry practices.
• Evening Grosbeaks that range from mountains of the west to northern portions of the east coast show population declines of nearly 78 percent amid increasing habitat damage and loss from logging, mining, drilling and development.
• Northern Pintail populations in the continental U.S. are down nearly 78 percent due to expanding agricultural activity in their prairie pothole breeding grounds.
• Greater Scaup populations that breed in Alaska, but winter in the Great Lakes and along Atlantic to Pacific Coasts are being hard hit by global warming induced melting of permafrost and invasion of formerly-southern species; populations are down approximately 75 percent.
• Eastern Meadowlarks, down 71 percent, are declining as grasslands are lost to industrialized agricultural practices. Increased demand for biofuel crops threatens increased agricultural use of lands that are currently protected, making both Eastern and Western Meadowlarks even more vulnerable.
• Common Terns, which nest on islands and forage for fish near ocean coasts, lakes and rivers, are vulnerable to development, pollution and sea level rise from global warming. Populations in unmanaged colonies have dropped as much as 70 percent, making the species’ outlook increasingly dependent on targeted conservation efforts.
• Snow Buntings, which breed in Alaska and northern Canada, are suffering from the loss of fragile tundra habitat as global warming alters and disrupts the Arctic’s delicate ecological balance; populations are down 64 percent.
• Rufous Hummingbird populations have declined 58 percent as a result of the loss of forest habitat to logging and development, in both their breeding range in the Pacific Northwest and their wintering sites in Mexico.
• Whip-poor-wills, down 57 percent, are vulnerable to fragmentation and alteration of their forest habitat from development and poor forest management practices.
• Little Blue Herons now number 150,000 in the U.S. and 110,000 in Mexico, down 54 percent in the U.S. Their decline is driven by wetland loss from development and degradation of water quality, which limits their food supply.