Birders, it’s that time of year: stand up and begin counting.

The 27th annual Great Backyard Bird Count (GBBC) will run Feb. 16 through Feb. 19.

An estimated half-million people participated in last year’s event and reported seeing more than 7,500 species of birds from 200-plus countries. 

“The GBBC gets bigger every year, and that’s such a positive thing,” said David Bonter, co-director of the Center for Engagement in Science and Nature at the Cornell Lab of Ornithology. “It’s well-established that time spent in nature is good for us. We also would not be able to track the long-term changes in bird populations without the eyes and ears of all our enthusiastic participants. The world is changing fast, and birds often reflect the impact of environmental change first.”

The act of birdwatching – and bird-counting – can be transformative for humans, too.

“I’ve grown to totally love something so simple as watching birds,” said longtime participant Marlene Koslowsky. “I now have a relationship with nature I never had before. It’s like my eyes are suddenly open.”

Knowing where birds are seen – and not – is crucial as weather fluctuations from climate change shift bird movements. During the past year, flamingos were spotted in Wyoming, a red-flanked bluetail was observed for the first time in New Jersey, and a cattle tyrant from South America appeared in Texas. Ornithologists speculate the birds may have been blown off course by increasingly fierce storms. The weather this year will also be influenced by El Niño, with warmer temperatures in North America impacting migration and the availability of food for birds.

To take part in the 2024 GBBC, each participant or group counts birds for any length of time (but for at least 15 minutes) and enters the birds they identified at each site they visited, whether in their backyard, a park or wilderness area, apartment balcony, or even the local landfill.

The GBBC website offers complete instructions for first-time participants, as well as helpful birding tips and birding app downloads. The website also features a new map for marking local GBBC community events. Birders can add events or find local events to join. A free, live-streamed webinar, Feb. 13 at 1 p.m., will provide more information and suggestions for GBBC-related activities.

The Great Backyard Bird Count is a joint project of the Cornell Lab of Ornithology, National Audubon Society and Birds Canada. The GBBC is made possible in part by founding sponsor Wild Birds Unlimited.

Pat Leonard is a writer for the Cornell Lab of Ornithology.