North American Wild Bird Population Drops by 29%

A study led by Cornell University and published in Science reports that the total breeding bird population in the continental U.S. and Canada has dropped by 29% since 1970. The team analyzed both long-term population surveys and radar imagery in their effort. Although scientists have long recognized declines in the populations of some species, it appeared that increases in other species, such as raptors and waterfowl, might offset the net decline. However, this study showed massive losses among birds in every biome. The study authors say habitat loss is a driving factor in the decline.