On Saturday, Dec. 19, close to 130 volunteers dispersed on a mission to count every visible bird and bird species during the San Diego Audubon Society annual Christmas Bird Count. San Diego Audubon, an organization dedicated to fostering the protection and appreciation of local birds, wildlife and habitats, coordinates the San Diego Christmas Bird Count as a portion of the world’s largest citizen science project. Saturday’s event mobilized 35 teams of volunteers spread out in a 15-mile-diameter circle centered on the Sweetwater River in Chula Vista. The circle’s boundaries extended south to the Tijuana River Valley, north to the Trolley Barn Park on Adams Avenue, east to Sweetwater Reservoir and west five miles offshore. Teams recorded 220 bird species, compared to 209 last year; the fourth-most diverse count of more than 2,400 recorded in the western hemisphere. The annual Christmas Bird Count provides a snapshot of San Diego’s ecosystem by recording the presence and abundance of bird species at a scale that scientists could never evaluate alone. Audubon climate scientists have used data collected from the Christmas Bird Count to analyze bird populations and their response to changes in climate, which has led to the conclusion that 314 species of North American birds are threatened by global warming. “We know bird populations respond to changes in our climate – we’ve watched the winter range of hundreds of bird species move nearly 40 miles to the north in just the past 50 years,” says Chris Redfern, executive director of San Diego Audubon. “The Christmas Bird Count helps us recognize such trends, collect data and better understand the effects of climate change so we can prioritize local conservation efforts to match. We’re incredibly grateful to everyone who gave a bit of their holiday time to participate on Saturday.” In 2016, San Diego Audubon will review the Christmas Bird Count results to inform local bird conservation efforts. For more information about San Diego Audubon and its annual Christmas Bird Count, please visit http://www.sandiegoaudubon.org.