One of the best days of the year for finding coins on the sidewalks of New York, according to Roger Pasquier, is March 18th, right after St. Patrick’s Day. In general, the best time is early morning, and the best weather is chilly: cold enough so that people have to wear gloves, but not so cold that they stay inside. Sundays are good; Mondays are bad. The west side of a southbound street is good because that’s where buses stop and people fumble with wallets as they get on. Snow is an impediment, at least until it melts. Then it can be helpful.

Pasquier, who is sixty-seven, is an ornithologist, who retired from the National Audubon Society in 2012. He spends every day of birding season in Central Park. But he is also an élite money hunter. He started out casually picking up coins, bills, and dropped MetroCards. “But then I said, Be scientific, keep track of this.” From 1987, when he began recording his findings, through 2014, he retrieved a thousand nine hundred and twenty dollars and eighty-seven cents. From 1987 to 2006, he averaged about fifty-eight dollars a year. Then Apple introduced the iPhone, and millions of potential competitors started to stare at their screens rather than at the sidewalks. Since 2007, Pasquier has averaged just over ninety-five dollars a year.

One Monday morning, Pasquier, who is compact and wiry, headed south from his apartment, on East Sixty-eighth Street, and explained the hazards of his craft. Good spirits, he said, are a liability. When you’re happy, you tend to look up, not down. “It takes a lot of will power to focus when you’re in a cheerful mood,” he said. On Second Avenue, between Sixty-second and Sixty-third, he dashed into the street, reached down, and grabbed a quarter.

“I can tell you’re just hate-agreeing with me.”

Which brought him to the second hazard of his hobby: oncoming cars. The best place to find coins is in the gutter of the street, where few people walk and there aren’t as many distractions, such as bottle caps or the circular stains of ground-in chewing gum. Pasquier tends to avoid eye contact with other pedestrians: “It’s important that I keep my eyes on where the money is.”

He maneuvered through crowds like a speed skater. His strategy comes from his main passion. Birds rely on a “search image,” he explained._“_They have a general sense of what their food or predator looks like and they become very attuned to those shapes.” A chickadee knows to dart the moment it senses the shadow of a hawk. Pasquier can find a coin by its shine or its shape, or by the sound it makes when dropped. Asked if he believes that picking up a penny brings you good luck, he said, “The penny is the luck.”

At Fifty-fifth Street and Second Avenue, Pasquier noticed a glint in the street and stepped out to retrieve a penny. It hadn’t been a bad day so far—twenty-six cents in thirteen blocks.

His greatest find, he said, occurred in 1995, in Grand Central Terminal. He spied the faint outline of a tightly folded bill; from a distance, he couldn’t tell if it was a one or a twenty. He approached discreetly. Then, he said, “like a heron spearing a fish, I jabbed out my arm.” Outside, he unfolded the bill and saw the face of Benjamin Franklin. First, he felt excited, then he got worried: perhaps the money belonged to a child heading out on his first trip alone? A friend made him feel better by suggesting that the bill had been dropped by a drug dealer.

South of Thirty-fourth Street, he cut over to Third Avenue, noting the number of bars there. (Alcohol is the ally of a coin hunter.) Then came a string of pennies, one of which had been run over so many times that the back looked like a dime. Another was bent like a taco. Money was hard to come by in SoHo. Near the entrance to the Staten Island Ferry, Pasquier stopped to tally his earnings: thirty-two cents. Then he looked down at his right foot. Behind it, shining in the sun, was a bright copper penny. “It just shows how easy it is to miss things,” he said, reaching down. ♦