Stan DeOrsey frequently thinks back on one of his favorite moments participating in the National Audubon Society’s annual Christmas Bird Count.

His group came upon a large bush that was “absolutely filled” with pine grosbeaks, an unusual site. Though the dusty reddish finches generally stay in Canada, Maine sees an irruption about once every 10 years. Even then, seeing so many in one place is a rare treat.

“Every time I see that bush, I think of those birds,” says DeOrsey,

Born in Auburn, DeOrsey now lives in Monmouth. He and his wife, Joan, have been birding for about 40 years and have been active in Lewiston’s Stanton Bird Club for about a decade. For most of that time, DeOrsey has also been Lewiston-Auburn’s coordinator for the Christmas Bird Count.

Overseen by the National Audubon Society, the annual count has been a fixture in the birding community since 1900.

“It’s pervasive. You can’t be involved with a club or birds in any kind of way without being exposed to it. If you’re interested in birds, you just run into it,” says DeOrsey.

As the name suggests, the count takes place each year on a single day during late December or early January. The Lewiston-Auburn count covers a 7.5-mile radius, with Bates College as the bullseye. Six teams of four or five birders each take a wedge of the pie, which includes not only Lewiston and Auburn, but parts of Sabattus, Lisbon, Green, Turner and Minot.

To DeOrsey, one of the most interesting things about the count is how many remarkable birds his group generally spots right in downtown L-A.

Because fish often become stunned tumbling over the Great Falls, the area at the base of the falls is a popular fishing location for large birds of prey.

“It’s memorable because you’re right in the middle of Lewiston and Auburn and you’re looking at these eagles and peregrine falcons. Most people aren’t even aware of them,” says DeOrsey.

Because the area at the base of the falls is always open, ducks are another common wintertime resident of downtown. DeOrsey has even spotted hooded mergansers, an eye-catching species of waterfowl with a bold white dotted crest on its head, skimming along the Androscoggin during the annual count.

As exciting as these individual sightings can be for birders, though, the true value of the annual count lies in aggregating the observations of tens of thousands of count participants across North America. Data collected each year helps wildlife biologists understand how populations of birds shift over time.

Even with his micro-view of the whole picture, DeOrsey has learned first-hand how wildly bird populations in Maine can fluctuate. Many of those numbers, though, aren’t fluctuating so much as moving in just one direction: down.

“Birds are in trouble. You can look at the bald eagles and you can look at peregrine falcons. They have been restored after the DDT problems and are coming back. Others are being devastated by habitat loss and climate change,” he says.

“Each year, the numbers in our count for most species have been dropping. We’re seeing all the same species, but lower populations.”

By pulling in numbers from across the United States and Canada, biologists can look at entire populations of species to understand whether such fluctuations represent a true blow to species, or whether birds have just shifted their habitats.

The count provides valuable data that helps biologists study how factors such as climate change, shifting landscapes from people planting nonnative plant species in their gardens and suburban developments creating more “edge” areas between forest and lawns, and a proliferation of backyard bird feeders affect migration patterns.

Our changing culture and climate have already had an impact on bird populations in Maine, and not always in predictable ways. In the last few years, counters in Maine have found many species of birds coming to Maine earlier or leaving later than in years past. Others, such as the cardinal, an ever-popular year-round resident, are relatively new residents of this area, appearing as recently as the 1970s.

Irruptions of birds, when birders see an unusually large number of birds from a particular species, are another occurrence the count can help to measure. For instance, due to a very cold winter across much of the Northeastern U.S., Maine had an irruption of snowy owls last winter. While it’s not unusual for individuals to venture into the state from Canada, where they usually spend the winter, they came in exceptionally large numbers, to the excitement of many.

While the Christmas Bird Count is the oldest and most well-known of what Audubon has come to call its “Citizen Science” programs, it is far from the only way average nature lovers can help biologists understand wildlife.

“Our Citizen Science initiatives try to engage citizens, both children and adults, to get actually get out and do some field work,” says Michelle Smith, communications manager for Maine Audubon.

“All of these little observations people make contribute to a bigger picture to help us understand on a state and national level how to make decisions that will protect these vulnerable species.”

And in the social media age, biologists are even using data from online sources to learn about birds and their habitats. eBird is an online birding tool created by the National Audubon Society and the Cornell Lab of Ornithology, a world leader in the study and conservation of birds.

Birders can drop pointers on a map detailing where they were birding and what they saw there. For its Important Birding Areas project, Maine Audubon made use of this tool by giving volunteers a list of areas of interest to visit and having them fill out their reports on eBird.

The organization released a list of important birding areas a little over five years ago, and is now in the process of updating that list using data from the project.

“(eBird) has made the analysis piece easier than ever,” says Susan Gallo, a wildlife biologist with Maine Audubon.

That’s a rapid change for an organization that, as recently as the early 2000s collected hundreds of paper checklists for each of its annual counts.

Here in Maine, the Maine Loon Project’s annual count is the oldest Citizen Science initiative, engaging approximately 1,000 volunteers across Maine to spend half an hour scanning the perimeters of more than 300 lakes and ponds for one of the state’s most iconic birds.

A program of Maine Audubon, the count has occurred every year since 1983 on the third Saturday in July. Through the count, Audubon has monitored the rebound of the species in Maine, from around 1,500 in the early years of the count more than twice that in recent years.

“There’s no way you could have a survey like this without volunteers. We need upwards of 1,000 people. You couldn’t hire 1,000 people for half an hour,” says Gallo.

Gallo adds that there are other benefits to using volunteers, too, including efficiency. Most of the people volunteering to survey lakes and ponds during the loon count use those same lakes and ponds recreationally, so they know their way around. A biologist would have to spend a significant amount of time getting to know the lay of the land, or in this case the water, before collecting any useful data.

For Maine Audubon, counting loons in the state is about much more than just knowing how many loons there are. The annual count helps the organization monitor water quality.

“If you have a loon, you have a lot of other good things going on in your lake,” says Gallo.

One of the earliest benefits of the loon count occurred not from counting the number of live loons that volunteers found, but in the loon corpses they reported. In an effort to learn what was behind loon mortality, Audubon partnered with Tufts University to perform necropsies on dead loons collected by volunteers – more than 500 loon carcasses over the last 25 years.

Through this study, they learned that many of Maine’s loons died of lead poisoning after swallowing fishing tackle. This led to legislation last year banning the sale of lead fishing tackle in the state, and the Audubon’s new tackle exchange program, created in hopes of reducing needless loon fatalities.

“We would not have been as successful collecting these loons if it weren’t for the awareness created among this group of dedicated volunteers,” says Gallo.

Other Citizen Science initiatives study populations of amphibians, brook trout and even roadkill.

“All projects start with a question,” says Gallo.

Audubon started its Wildlife Road Watch project in 2010, beginning with the question of how to reduce wildlife traffic fatalities, particularly for species that are threatened.

“We’d like to understand better what different types of animals are crossing the road, both successfully and not successfully,” says Barbara Charry, a wildlife biologist with Maine Audubon who worked on developing the program.

Through this project, biologists seek to have a better understanding of how different factors impact wildlife survival rates – including the amount of traffic, average speed, visibility and curves. The study also looks at whether survival rates vary among species or at different times of year.

Due to their famously slow gait, turtles are among the species most in need of help. In Maine, a few reptile species – the black racer snake, the spotted turtle and Blanding’s turtle – are all in danger of becoming extinct if they aren’t protected from traffic fatalities.

“Turtles live a long time and take a long time to mature, so when a breeding adult is killed, it takes a very long time for it to be replaced. Just a couple of road deaths each year can wipe out a population in less than 50 years,” says Charry.

There are two ways to volunteer for the Wildlife Road Watch. Audubon takes random reports of roadkill sightings year round. Those who wish to participate simply fill out a sighting report on Maine Audubon’s website

Others volunteer to monitor specific stretches of road at set times during the year.

“Once we know what areas to focus on, we can definitely make mitigations to help wildlife cross safely and to help people travel more safely, too,” said Charry.

Appropriate fencing can funnel animals away from dangerous crossings and into specially designed underpasses. The focus of these studies is primarily in York and Cumberland counties, where the bulk of threatened species live, and where traffic is heaviest.

“We usually have several of these projects going on. Some come and go, some are long-term,” notes Gallo.

Some like the Christmas Bird Count and the ongoing Breeding Birds Survey are national efforts that local Audubon groups support. Others come through partnerships with local organizations such as the Maine Department of Inland Fisheries and Wildlife, who tap Audubon because of their wealth of experience engaging the general public in amateur field work.

For the past two years, Audubon-organized volunteers participated in a bat census to determine the effects of White Nose Syndrome on bat colonies in Maine. As a result of the fungal disease, more than five million bats in the Northeast have died since 2007. Biologists predict the little brown bat could face extinction by 2026 if current trends continue.

“The counts were really dismal,” says Gallo.

Volunteers found no bats at all in the historic colonies they visited. While that result was disappointing for volunteers and biologists alike, the study proved to be important.

The dearth of bats to count led the U.S. Fish and Wildlife Service to consider adding three species of bats — northern long-eared bats, eastern small-footed bats and little brown bats — to the Endangered Species List.

Other studies include a national amphibian survey that’s in its 17th year, a pioneering owl study in the early 2000s primarily for the purpose of creating a protocol for how to study owls and an ongoing partnership with Trout Unlimited and Maine IF&W to survey wild brook trout in unstocked and previously unsurveyed waters.

Peter Wohl, an addiction counselor and Registered Maine Guide who lives in Oakland, was among the early volunteers for the Brook Trout study in 2012, heading out with his son to a collection of remote ponds in the Rangeley area.

“I would like my grandson to be able to see a wild brook trout someday,” says Wohl of his participation.

“I think it’s just wonderful that Maine has this wild native population of trout. They’re a beautiful part of our ecosystem and they only thrive in the cleanest, coldest water, so they’re a bellwether for the health of our waters.”

Beyond that, the experience was fun for Wohl, because just getting to some of those all-but-forgotten ponds offered a challenge for the seasoned outdoorsman. Reliable trail maps were hard to come by, if trails existed at all, and many of those that were marked were overgrown and required extensive bushwhacking.

While that may not sound like everyone’s idea of a restful weekend, Wohl said it was central to his experience.

“It was an adventure. It’s exciting throwing a line into a pond few people get to fish and not knowing what you’re going to pull out,” he says.

Wohl sees another benefit to participating in Citizen Science projects. One of his professional interests is ecopsychology, an emerging discipline that begins from two basic premises: humans need nature for our well-being and nature needs humans to be psychologically connected to it for its preservation.

“I think we all experience some sense of nurturance, some inner-peace when we’re in a rich natural setting,” says Wohl, whose guide service, Moosis Zen Journeys, provides wilderness trips designed to foster that connection through exercises that help participants stop and pay attention to their surroundings.

Smith agrees, “Once you stop and look and listen you’ll start to notice all kinds of things you usually take for granted. You’re more in tune with the environment and what’s happening. The first step is to slow down and pay attention. For families, it’s a great activity to get out and do together, just going out and listening for frogs or standing on the side of the road and seeing what wildlife goes across.”

Charry puts it even more simply, “It’s just a great way to get outside and make a difference for wildlife in an easy, fun way.”

For more information about Citizen Science, visit www.maineaudubon.org.