The 16th annual Great Backyard Bird Count will run Friday through Monday.

Millions of bird watchers across North America will take part in this citizen science effort. Led by the Audubon Society and the Cornell Laboratory of Ornithology, anyone – expert or novice – can count birds from wherever they are and enter their tallies online.

Last year, participants sent in more than 100,000 checklists tallying 623 species and more than 17 million individual birds.

The data in these reports provides valuable information on the status of bird populations and movements.

If you would like to take part, go to birdsource.org/gbbc for more information and to submit your observations during the Bird Count weekend.