He’d been hosing down his bear cage when I rang. Yates has about 200 exotic animals at his house. Most are pets that the F.W.C. confiscated from owners who failed to comply with state regulations and then entrusted to Yates’s one-man nonprofit, Wildlife Rescue and Rehabilitation. There were 17 tigers, some leopards, cougars, a pile of alligators in a concrete pool and a dusty battalion of large African spurred tortoises. Yates likes tortoises — he also keeps a single Galápagos tortoise as a pet. “I’ve been married five times,” he told me. “In one of my divorces, I lost $100,000 worth of tortoises.”

At his desk, Yates unfolded a map of Tampa Bay. But he found he had to flip the map over, then consult other maps, at different scales, to trace the macaque’s entire odyssey. “It’s an amazing feat, when you think about his travels,” he said. Since 2009, Yates estimates that he has gone after the animal on roughly 100 different occasions. The monkey was his white whale. He claimed to have darted it at least a dozen times, steadily upping the tranquilizer dosage, to no avail. The animal is too wily — it retreats into the woods and sleeps off the drug. A few times, the monkey stared Yates right in the eye and pulled the dart out.

For the last two years, the macaque seems to have lingered in the same area of South St. Petersburg, ranging between a bulbous peninsula and the small island of Coquina Key, about two miles away. Yates still received calls about the animal — one came in the previous week. But the trail went cold a long time ago. Sightings were seldom reported now. As a woman on Coquina Key named Rosalie Broten told me: “Nobody wants the monkey to be captured. Everybody wants it to be free.”

The citizenry of Tampa Bay was adamantly pro-monkey. People had long been abetting the animal, leaving fruit plates on their patios. A few people, one F.W.C. officer told me, called the agency’s monkey hot line to report that they’d seen the macaque several hours or even a couple of days earlier — offering totally useless intelligence, in other words, presumably just to stick their thumbs in the government’s eye. The Mystery Monkey of Tampa Bay, as people called it, had very quickly become a celebrity. There were at least two styles of Mystery Monkey T-shirts on offer, and a catchphrase: Go, Monkey, Go. As the macaque passed through the town of Oldsmar, a self-storage facility threw the monkey’s picture on a digital billboard with the message: “Stay Free Mystery Monkey.” And a Facebook page for the animal got 82,000 likes. “The taxpaying citizens of Tampa have been driven bananas by the out-of-touch political establishment,” the monkey wrote on its blog at the end of 2010, announcing its run for mayor.

At no point had the macaque threatened or hurt anyone. So it was easy for the public to see the authorities — who, on at least a couple of occasions, surrounded the macaque with rifles and Tasers drawn, or hovered overhead in helicopters, beaming video surveillance to troops on the ground — as bullying or wasteful. (“In this economy,” one television reporter quipped, “you have to wonder if it’s time to stop monkeying around.”) Lt. Steve De Lacure of Florida Fish and Wildlife told me, “The general public perceives that we’re the Gestapo.” He was adamant that his agency was not “chasing” the animal, and had deployed officers only a handful of times, when they felt they had a reasonable shot at capturing the macaque. He didn’t even like it when I used the word “pursue.”

I sympathized with the F.W.C. What they had to do was unpopular, but their sense of duty was unshakable. They were even prepared to shoot the animal dead if, in a given situation, tranquilization wasn’t an option. And they knew they’d be vilified if it came to that. But they took a somewhat traditional view: the American people had a right to be protected by their government from wild monkeys. It was disorienting to watch the people of Tampa Bay champion the monkey’s rights instead.