Long-term declines in bird populations in tropical agricultural countryside

Significance As agricultural lands rapidly expand in the tropics, they become critical for the future of tropical biodiversity, but little is known about their long-term conservation value. Over 12 years in Costa Rica, we measured the abundance and diversity of birds in agricultural areas and embedded forest remnants. We recorded 185 bird species in coffee plantations and 230 species at forest sites, but 69 out of 112 populations showed...