The National Audubon Society just dropped a bombshell of a report detailing 20 common North American birds whose populations have declined over the last 40 years. The list of birds, all of which have lost at least half their populations in just four decades, is both surprising and disconcerting, indicating that even the most robust species may be vulnerable to our rough and thoughtless treatment of this planet.

A new analysis by the National Audubon Society reveals that populations of some of America’s most familiar and beloved birds have taken a nosedive over the past forty years, with some down as much as 80 percent. The dramatic declines are attributed to the loss of grasslands, healthy forests and wetlands, and other critical habitats from multiple environmental threats such as sprawl, energy development, and the spread of industrialized agriculture. The study notes that these threats are now compounded by new and broader problems including the escalating effects of global warming. In concert, they paint a challenging picture for the future of many common species and send a serious warning about our increasing toll on local habitats and the environment itself.

Among the most severely impacted species on Audubon’s list of 20 Common Birds in Decline are the following:

  • 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.
  • Whip-poor-wills, down 57 percent, are vulnerable to fragmentation and alteration of their forest habitat from development and poor forest management practices.

Rounding out this list are familiar birds like Boreal Chickadee, Loggerhead Shrike, Field Sparrow, Grasshopper Sparrow, Black-throated Sparrow, Lark Sparrow, Common Grackle, American Bittern, Rufous Hummingbird, Horned Lark, Little Blue Heron, and Ruffed Grouse.

Audubon does point out that these Common Birds in Decline are not in immediate danger of extinction, even though some of them are perilously close to the traditional 500,000 bird threshold that designates “common” status. Though I’m just a single observer, I can certainly vouch for the apparent decline of some of these species. Just recently, I either barely sighted or outright missed species like Grasshopper Sparrow and Boreal Chickadee in places where they should have thrived. Northern Pintail was uncharacteristically rare in the NYC area this winter, though buntings and larks seemed to do well by the ocean. But by the same token, one set of eyes is insufficient to track these changes; Common Grackles may be taking a hit in other places, but they couldn’t be more abundant around here. That’s why citizen science initiatives like the Christmas Bird Count are so critical in producing both the quantity and quality of data ornithologists require to track population trends.

How about you? In your observations of North American avifauna, have you been missing these birds or other previously common ones?

Written by Mike
Mike is a leading authority in the field of standardized test preparation, but he's also a traveler who fully expects to see every bird in the world. Besides founding 10,000 Birds in 2003, Mike has also created a number of other entertaining but now extirpated nature blog resources, particularly the Nature Blog Network and I and the Bird.