A crowdsourcing tradition which goes back 113 years – facilitated by the National Audubon Society. Last year 63,227 observers, spread across over 2,200 “circles” around the world, collected the data.
“From December 14 through January 5 tens of thousands of volunteers throughout the Americas take part in an adventure that has become a family tradition among generations. Families and students, birders and scientists, armed with binoculars, bird guides and checklists go out on an annual mission - often before dawn. For over one hundred years, the desire to both make a difference and to experience the beauty of nature has driven dedicated people to leave the comfort of a warm house during the Holiday season.
Each of the citizen scientists who annually braves snow, wind, or rain, to take part in the Christmas Bird Count makes an enormous contribution to conservation. Audubon and other organizations use data collected in this longest-running wildlife census to assess the health of bird populations - and to help guide conservation action.”
In graph, an example of the report that summarizes some of the data collected.