Declines in Common and Migratory Breeding Landbird Species in South Korea Over the Past Two Decades

Population declines in terrestrial bird species have been reported across temperate regions the world and are attributed to habitat loss, climate change, or other direct mortality sources. North American European studies indicate that long-distance migrants, common species, associated with grasslands agricultural lands declining at greatest rates. However, data from East Asia on avian population trends drivers extremely sparse. We modeled changes occupancy of 52 breeding landbird South Korea between 1997–2005 2013–2019. Thirty-eight percent showed evidence declines, seven these were severely (46–95%). Occupancy Black-capped Kingfisher ( Halcyon pileata ) populations dropped most precipitously over study period. Among migrants (9/20) (14/20) more rapid than groups. Declines five two appeared be affected by land-cover change. causes change (46/52) remains cryptic. Based our results, we suggest an immediate re-evaluation species’ conservation status legal protection levels for Korea, a dedicated survey design analysis effort continued monitoring populations. Because many exhibiting migrate beyond national boundaries, international collaborations will required better quantify full annual cycle, understand mechanisms declines.