Christmas Is Bird-Counting Season For 60,000 Americans

This winter marks the 117th year of a scientific holiday tradition — the National Audubon Society’s annual Christmas Bird Count. Every year beginning on Dec. 14,1 thousands of birders around the world, organized into local bird-watching “circles,” head out to count and record millions of bird sightings. The count will end Jan. 5, after which the bird-sighting data will be compiled, edited and entered into the Christmas Bird Count database.

The count is an enormous undertaking in citizen science. Last year, about 60,000 people in the U.S. participated in nearly...