For its 124th annual Christmas bird count, The Audubon Society of Western Pennsylvania is having counts Saturday, Dec. 16, in Buffalo Creek Valley at the Todd Nature Preserve and Buffalo Creek Nature Park, and Dec. 31, at Succop Nature Park in Penn Township.

The Christmas bird count is the world’s longest-running citizen science project, according to the society. People of all ages and birding experience count birds that they see on the count dates and the data is used to measure changes in the environment and in bird populations.

Participation is free and prior experience is not necessary. New bird-watchers can be teamed up with experienced bird-watchers. Bird count training classes can be found on the society’s website, aswp.org/events.

Bird count groups can be found here.