For nearly two weeks, we had been getting up every day at 3:30 a.m. to patrol a nearly impassable road, looking for signs of the jaguar. Finally, tracks on the old logging road outlined a huge feline paw –jaguar – and led from the road into la Selva Maya, a vast expanse of tropical forest stretching through southeastern Mexico, northeastern Guatemala and Belize. The five dogs were already in a frenzy, sniffing the scent of el tigre. We on the team waited. Pancho Zavala, the manager of the hounds whose expertise has earned him the title of Don Pancho, would decide.

Without speaking, he nodded to Cuauthemoc Chavez, the field biologist in charge. That was it. We were going to chase the jaguar and capture it.

Don Pancho warned us that a male jaguar usually heads straight across country. The terrain offered jagged limestone outcroppings underfoot, spiny vines and trees in dense undergrowth, as well as creatures such as the fer-de-lance, the deadly poisonous pit viper.

No matter, we were eager to go. Everyone quickly readied for the chase.

Chavez gathered the equipment, including the radio collar and antenna. Miguel Amin, a biologist studying jaguar prey species,