Great horned owls and a gilded flicker on a saguaro cactus in the Sonoran Desert, Arizona

Counting crows...and every other bird. National Audubon Society's Christmas Bird Count

It's that time again! Grab your binoculars and bird guide and head outside to start counting. The National Audubon Society's Christmas Bird Count starts on December 14 annually and runs until January 5. Originating as an actual hunt in the 19th century, on Christmas Day in 1900 someone had the bright idea to stop killing the birds and instead just observe them.

Conducted entirely by volunteers, the Christmas Bird Count is the largest citizen science project in the world. It helps to track the health and well-being of bird populations and is vital to conservation efforts. Without it, species like the great horned owl and the gilded flicker, seen nesting in a saguaro cactus in today's photo of Arizona's Sonoran Desert, could end up being underrepresented and possibly endangered.