For the last 20 years, the National Audubon Society has encouraged people to go into their backyards or to their local parks and count the birds they see. It's called The Great Backyard Bird Count. It began in the U.S. and Canada. Now, 130 countries participate in the global data-gathering weekend.
Cornell Lab and the National Audubon Society use the data from these "citizen scientists" to provide a snapshot of the distribution of birds around the world. Trina Bayard is the director of bird conservation at Washington Audubon.
"Citizen scientists allow us to achieve a coverage of the geography - or the landscape, the state, the country, the world - in a way that scientists could never do on their own," she said.
Learn more at the Great Backyard Bird Count website.