Prodigal Beaver.(The Talk of the Town)

One recent evening, Stephen Sautner sat behind his desk in the Bronx Zoo's administration building, hoping that Jose hadn't washed away. Jose is an American beaver, and after Sautner discovered him, in February, during a lunchtime stroll along the Bronx River, the zoo celebrated Jose as the first beaver to claim New York City residence in more than two hundred years. ("Dam! The Beaver Returns to New York," Gothamist reported.) But a month ago a tempest of rain, sleet, and snow submerged Jose's lodge, a twelve-foot-long, four-foot-high engineering marvel of sticks, rocks, and mud. No one had seen him since.

Jose's forebears had a storied, if strained, relationship with New York. The state once claimed tens of thousands of beavers--Albany was originally named Beverwijck, "district of the beavers"--but, even if the beavers managed to elude John Jacob Astor's traps, then deforestation, factory waste, pop bottles, and discarded tin lizzies evicted them from their watery tenements. For centuries, the best places in the city to see a beaver have been on the city seal, the ceramic tiles of the Astor Place subway station, and the Field House of the Brearley School, home of the Beavers. Tonight's mission: find Jose.

Sautner, who is just over six feet tall, has the goatee of an avid woodsman ("You should see him throw a hatchet," a friend said). He pulled on a blue North Face Gore-Tex jacket, slung a thermal-imaging night-vision monocular around his neck, and stepped into a pair of waterproof boots. "Beavers are active at night," he said. "Who knows? If we're going to find him, we've got a good shot tonight."

Sautner had invited Eric Sanderson, from the Wildlife Conservation Society, to join the hunt. "Full disclosure," San-derson said, as the two walked toward the river, past an empty sea-lion pool. "I first thought Jose might be a muskrat." He went on to explain that Jose is named for Jose Serrano, who represents the Bronx in Congress.

The two men hopped an iron railing and hiked gingerly down the riverbank, which was muddy and patched with snow. The floodwaters had receded, and their steps made a sucking sound. On the opposite bank, ten ...