To find the quickest declines, look where birds are most abundant
Areas where birds are most abundant are also seeing the most rapid shrinking of bird populations. Birds are facing declines around the world, and breeding birds in North America are facing a more than 25% loss since 1970. In a study published in Science, researchers used citizen science data from the eBird app to determine where birds were facing the most trouble in North America. Looking at data from over 36 million eBird checklists from 2007 to 2021, the team developed population trends for 495 bird species in North America, Central America and the Caribbean. Overall, they found that 75% of bird species are declining across their ranges. However, 97% of species are experiencing both gains and losses depending on their locations. In addition, the team revealed that birds are declining fastest in places where they are the most abundant, particularly in birds that breed in grasslands and drylands.
