"The Jaguar Freeway"

"The pounding on my door jolts me awake. 'Get up!' a voice booms. 'They caught a jaguar!'

It's 2 a.m. I stumble into my clothes, grab my gear and slip into the full-moon-lit night. Within minutes, I'm in a boat with three biologists blasting up the wide Cuiabá River in southwestern Brazil's vast Pantanal wetlands, the boatman pushing the 115-horsepower engine full throttle. We disembark, climb into a pickup truck and bump through scrubby pastureland.

Half a mile in we see them: two Brazilian biologists and a veterinarian are kneeling in a semicircle, their headlamps spotlighting a tranquilized jaguar. It's a young male, about 4 years old: He's not fully grown and the dagger-like, two-inch canines that protrude from his slack jaw are pearly white and show no signs of wear."

Sharon Guynup reports for Smithsonian magazine with photographs by Steve Winter in the October 2011 issue.