This winter marks the 125th year of Audubon’s Christmas Bird Count, in which bird nerds across the Western Hemisphere venture outside to record all the birds they see and hear.Scientists use that data to understand how birds are faring, where they’re moving, and what they’re up to when it’s not breeding season. With 125 years under its belt, the Christmas Bird Count is the longest-running community science program in the world.How do scientists use this data? And what have they learned in those 125 years? Ira Flatow talks with Dr. Brooke Bateman, senior director of climate and community science at the National Audubon Society, and Dr. Janet Ng, wildlife biologist at Environment and Climate Change Canada in Regina, Canada.Transcripts for each segment will be available after the show airs on sciencefriday.com. Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.