PT - JOURNAL ARTICLE AU - Rosenberg, Kenneth V. AU - Dokter, Adriaan M. AU - Blancher, Peter J. AU - Sauer, John R. AU - Smith, Adam C. AU - Smith, Paul A. AU - Stanton, Jessica C. AU - Panjabi, Arvind AU - Helft, Laura AU - Parr, Michael AU - Marra, Peter P. TI - Decline of the North American avifauna AID - 10.1126/science.aaw1313 DP - 2019 Oct 04 TA - Science PG - 120--124 VI - 366 IP - 6461 4099 - http://science.sciencemag.org/content/366/6461/120.short 4100 - http://science.sciencemag.org/content/366/6461/120.full SO - Science2019 Oct 04; 366 AB - Because birds are conspicuous and easy to identify and count, reliable records of their occurrence have been gathered over many decades in many parts of the world. Drawing on such data for North America, Rosenberg et al. report wide-spread population declines of birds over the past half-century, resulting in the cumulative loss of billions of breeding individuals across a wide range of species and habitats. They show that declines are not restricted to rare and threatened species—those once considered common and wide-spread are also diminished. These results have major implications for ecosystem integrity, the conservation of wildlife more broadly, and policies associated with the protection of birds and native ecosystems on which they depend.Science, this issue p. 120Species extinctions have defined the global biodiversity crisis, but extinction begins with loss in abundance of individuals that can result in compositional and functional changes of ecosystems. Using multiple and independent monitoring networks, we report population losses across much of the North American avifauna over 48 years, including once-common species and from most biomes. Integration of range-wide population trajectories and size estimates indicates a net loss approaching 3 billion birds, or 29% of 1970 abundance. A continent-wide weather radar network also reveals a similarly steep decline in biomass passage of migrating birds over a recent 10-year period. This loss of bird abundance signals an urgent need to address threats to avert future avifaunal collapse and associated loss of ecosystem integrity, function, and services.