Wired Magazine introduced the term "crowdsourcing" to the lexicon in 2006 to describe a generation of new, user-generated websites like Wikipedia. But crowdsourcing was, by then, old hat for ornithologists, who have been using it — to great effect — for well over a century.

This Saturday at 5:30 a.m., the Audubon Society's Elissa Landre and her team of 10 will strike out in the predawn darkness, canvassing a 15-mile circle in the woods around Millis, Mass., "to see, and mostly listen for, screech owls great horned owls and the barred owl.

From sunrise until sunset, they will hike and drive prescribed routes in teams, painstakingly recording every single bird they see. Every owl. Every starling. Every chickadee. Every goldfinch.

"We're also compiling information on the weather condition, the amount of snow cover, the percentage of the area that’s frozen, and we record all that information," Landre said.

Landre's stalwart gang of enthusiastic volunteers won’t be alone. Over the next three weeks more than 2,500 groups like hers will complete counts throughout the western hemisphere. This is the Audubon Society's Annual Christmas Bird Count. It’s happened every year since 1900. And all 114 years of detailed info is compiled in a staggering, accessible database — an indispensable ornithological gold mine.

"You couldn’t possibly fund a study that looks at what’s happened with birds over half the continent over three quarters of a century," said Geoff LeBaron, director of the Annual Christmas Bird Count for the National Audubon Society. "But by looking at citizen-science data sets where people with a passion about something are gathering data and contributing it to a database, then it's available for scientists to use and do their analyses on."

With some 70,000 citizen-scientists collecting — everyone from high-school students to retired college professors — collecting data each year, how reliable can it be? How do they know they aren’t just counting the same birds over and over again?

"People have routes that they take and areas that they cover and you don’t retrace your steps, and you don’t recount if you do have to trace your steps," LeBaron said.

OK. Well, what about the fact that some people might not even know what kind of bird they are looking at?

"Anyone who is new to birding or new to the area wouldn’t be out alone," LeBaron said. "They’ll always be with someone who knows the birds and the area."

Fine. But how about the fact that some circles have way more people than others, and not everyone is out for the same period of time?

"More people in more areas are going to count more birds, but if you actually weight the data for effort [which they do] then you get a real feel for what’s happening over time across the continent," LeBaron said.

The proof is really in the pudding. LeBaron says the Audubon Society fields multiple requests for their data every single week — from researchers, conservationists and teachers. It’s provided scientists with a real world look at the effects of climate change.

"What we’ve been able to track is how birds have shifted over the last 50-70 years in terms of the actual center of abundance of their range — and that center of abundance, that place where your most likely to find the most of that species has actually shifted significantly northward for 2/3 of the species we’ve studied," LeBaron said.

And it’s now helping them chart a course for the future.

"The exciting thing now is our recent climate change report is looking at what might be happening based on different climate change scenarios in the next 20, 50 and 80 years," LeBaron said. "It’s a whole new way at looking at conservation really."

And it’s all thanks to tens of thousands of citizen scientists, who Landre and LeBaron both say, yes, are excited about the science, but come out each year because of their passion for our fine feathered friends, and for each other.

"We start at 5:30 in the morning and by 4:30 in the evening it's already sunset, so we gather for soup and stories of our days in the field, and that’s one of the reasons that people are so avid about doing their counts, because not only do they get to see a lot of great birds, they get to see a lot of their great friends while they’re doing it."

A number of area circles will be doing their counts in the coming days, including in Millis and in Concord. If you're interested in participating, visit the Audubon Society's Christmas Bird Count page.