Wild birds are 3 billion fewer than in 1970, study finds

A new study reports nearly 3 billion fewer wild birds in the United States and Canada since 1970, a decline of about 29% from roughly 10.1 billion to 7.2 billion, based on weather radar, long-term surveys and modeling.

Researchers report a large decline in wild bird numbers across the United States and Canada. The study estimates the bird population fell from about 10.1 billion in 1970 to roughly 7.2 billion, a drop of about 29%. The analysis combined weather radar data, 13 long-term bird surveys and computer models to estimate trends for 529 species. The study emphasizes population loss rather than extinctions. Key facts: - The study used weather radar, long-running surveys and statistical models to estimate trends for 529 North American bird species. - Overall bird numbers are estimated at about 7.2 billion now, down from an estimated 10.1 billion in 1970, a decline of roughly 29%. - Many common species showed substantial declines in the analysis, with notable losses reported among various sparrows, meadowlarks and bobwhite quail. Summary: The reported decline reflects fewer birds across many species and habitats, including losses among birds that were once common. Undetermined at this time.