Bird watchers are invited to take part in the 13th annual Great Backyard Bird Count, Friday through Feb. 15, a free event that will join tens of thousands of volunteers counting birds in their own backyards, local parks or wildlife refuges.

Each checklist submitted by these “citizen scientists” helps researchers at the Cornell Lab of Ornithology, the National Audubon Society and Bird Studies Canada learn more about how the birds are doing—and how to protect them.

Last year, participants turned in more than 93,600 checklists online, creating the continent’s largest instantaneous snapshot of bird populations ever recorded.

“Even if you can identify a few species you can provide important information that enables scientists to learn more about how the environment is changing and how that affects our conservation priorities,” said Audubon Education Vice President Judy Braus.

Participants from novice bird watchers to experts count birds for as little as 15 minutes (or as long as they wish) on one or more days of the event and report their sightings online at

www.birdcount.org

. The site has more information on the count, tips to help identify birds and special materials for educators.

—Cornell University