The GBBC "is an annual [mid-February] four-day event that engages bird watchers of all ages in counting birds to create a real-time snapshot of where the birds are across the continent." Site features material about participation, blog, and photo galleries back to 2005. View results back to 1999 using maps, U.S. state and Canadian province tallies, or top ten lists. Also includes material for children and links. From the Cornell Lab of Ornithology and Audubon.