Photo: Gillian Pullinger/Alamy

In 1996, a young naturalist in San Francisco joined a group of birders on an ambitious Big Day excursion. The plan: drive, and drive, and drive, and hopefully see 150-plus bird species between dawn and dusk.

Josiah Clark, an ecologist now in his early 40s, still remembers that 300-mile road trip with a bit of distaste—how they all piled in and out of the car every 20 minutes and spent hours elbow to elbow while fighting for legroom and a view out the window. “After that, I was like, ‘I don’t ever want to do a Big Day by car again,’” Clark says.

That event prompted a radical shift for Clark. The next year, he rode his bicycle 90 miles and climbed more than 10,000 feet on the first of his biking Big Days. He has since completed numerous bird-focused long rides of up to 160 miles, usually with several companions. Each year, he says, more birders join him, and he also leads increasingly popular organized tours of varying lengths. Most recently, in March, he took 28 birders around San Francisco.

Pedal-powered birding might not be for everyone—heavy gear, safety concerns, injuries, or mobility impairments can be barriers—but around the country, more birders are choosing to break away from their car and opt for bicycles. They cite a combination of factors, from a desire to lower their carbon footprint to the benefits of being able to stop on a dime and tune into a pretty birdsong, while covering more ground than walking allows.

Upstate New York birder and cyclist Cullen Hanks, who has also resided in California and Texas, says he’s seen growing interest, especially on the West Coast where there’s “a confluence of critical mass in both birding and biking cultures.” There, topographical diversity lends itself to covering multiple habitat types and seeing lots of birds in the course of a ride. “It’s such a great way to move across the landscape,” he says.

In Minneapolis, naturalist Sharon Stiteler, a cyclist and writer known by the name Birdchick, interprets an uptick in interest as a response to both worsening traffic in cities and more awareness of the impacts of driving cars. “If you can find a way to get some exercise and avoid being stuck in a car in rush-hour traffic, you’ll do it,” she says.

It helps that Minneapolis is one of the country’s most bike-friendly cities, says Gregg Severson, who is currently pursuing a “big green half year” by only counting birds seen while venturing from home using human power. “If people don't feel safe biking, they won't go birding by bike,” he says. Many of the city's bike paths pass through parks or near lakes that offer prime migratory bird habitat, he adds.

Cycling offers other benefits; it can be more affordable than driving, and it provides transport for kids and adults who can’t drive or, like Severson, don’t own a car. Beyond the cramped interior of a sedan and the frustration of traffic jams and parking lot queues, bikers can listen while they travel, quickly turn around, take their bikes onto trails—and do all of this while making almost no noise themselves. While cyclists usually move more slowly than motorists, Clark says, each mile traveled can be more productive from the saddle, especially in dynamic landscapes.

At the end of the trail ride, they’d seen more than 100 bird species.

California birder Genna DeVries was already a seasoned cyclist when she joined one of Clark’s guided birdwatching bike rides in 2015 at the Point Reyes National Seashore. At the end of the trail ride, they’d seen more than 100 bird species. She realized how much she was missing, by sight and sound when contained in a car or limited by the slow pace of walking, especially over monotonous terrain. "I thought, ‘This is a much better way to see a lot of birds,’” DeVries says.

Since then, she’s added mounts and racks to one of her mountain bikes to hold her scope, camera, and binoculars. She now leads monthly trips of her own, which she organizes via the site Meetup. She finds biking the perfect compromise between driving and walking. “If nothing’s happening in one place, we’ll just zip to the next hotspot,” she says. (On the other hand, taking your time is sometimes still the point, such as on Audubon California's recent 1.6-mile "Slow Ride" along the Los Angeles River.)

Still, the shift from car to bike is hardly a revolution—at least not yet—and many birders still burn volumes of fossil fuel in cars and planes to get to destinations and, perhaps, add a coveted species to their life list. Clark, who usually tries to bird door-to-door by bike, notes that many birding organizations inadvertently encourage emissions by promoting Big Days in which participants collectively drive thousands of miles.

There is, however, growing awareness of this issue, as festivals encourage birders to reduce their carbon footprints and globe-trotting competitive birders net Big Year records while offsetting their emissions. The World Series of Birding now offers a prize category to the team that sees the most birds without burning carbon. Similarly, the Great Texas Birding Classic promotes a “green” tournament category in which birds cannot be counted when seen from motor vehicles—people bike, walk, or even canoe instead. In Oklahoma, the Payne County Audubon Society's Big Day prize for non-motorized transport suggests riding by bike or perhaps horseback.

Going carbon free was part of Dorian Anderson’s goal in 2014 when he started out on his pedal-powered Big Year around the U.S. In the end, he rode 18,000 miles and tallied 618 bird species. More than a scoresheet of numbers, though, his trip was meant to be a deviation from the standard vehicle-centric approach to Big Years. Anderson says he hoped his endeavor “would rub off on people.”

But five years after his green Big Year, Anderson, who still travels by airplane but does all his near-home birding without driving, is discouraged by the slow pace of change. While more birders now ride bikes than a decade ago, the shift “is statistically insignificant," he says.

“There’s a disconnect [in the birding community]," Anderson say, "because we read how climate change is affecting the very birds we want to see, yet people still burn a lot of fossil fuel in pursuit of the exact birds that are threatened."