avian science Citizen Science: Mid-winter Eagle Survey By Dale Bolton • Jun 23, 2014 Wikimedia Commons Listen Listening... / 4:29 When America adopted the bald eagle as the national symbol in 1782, there may have been 100,000 nesting eagles. But the eagle population declined, in part due to pesticides. Citizen Science: Breeding Bird Survey By Dale Bolton • Jun 16, 2014 Cornell Lab of Ornithology Listen Listening... / 4:29 The North American Breeding Bird Survey is a cooperative effort between the United States and Canada. Citizen Science: Bird Banding By Dale Bolton • Jun 9, 2014 Powdermill Nature Reserve Listen Listening... / 4:29 How do scientists get the data they need to study birds? A lot of data is collected by volunteers, "citizen scientists," through bird surveys and bird banding.