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.