Birds of a feather are slowly losing the members that flock together.

We read in the Christian Science Monitor that some bird populations are getting smaller and smaller:

New data show the populations of some of America's well-known birds in a tailspin, thanks to the one-two punch of habitat fragmentation and, increasingly, global warming.

The data comes from a new report conducted by the National Audubon Society, which shows that the populations of 20 common bird species declined by more than 50 percent over the last four decades.

Terns, whippoorwills, meadow larks, sparrows, and the ruffed grouse all made the list, indicating that the losses are occurring in most regions of the country. Although this study was not peer reviewed, it adds to the body of research and will help scientists determine how changes to the environment affect our feathered friends.

Thursday's study updates and expands earlier efforts: It adds to the annual Breeding Bird Survey, which is done by the US Geological Survey, some 40 years of data gathered by thousands of volunteers from the Audubon Society's Christmas Bird Count program. Together, these data make the new study one of the most comprehensive looks at bird-population trends in North America.

Thankfully, many of the species listed in the study still have healthy populations, despite the dramatic declines.

If only the same were true for our checking and saving accounts.

This article originally appeared in Plenty in June 2007. This story was added to in July 2009.

Copyright Environ Press 2007.