Rabinowitz is the world's leading jaguar expert, and he has begun to realize his dream of creating a vast network of interconnected corridors and refuges extending from the U.S.-Mexico border into South America. It is known as Paseo del Jaguar—Path of the Jaguar. Rabinowitz considers such a network the best hope for keeping this great New World cat from joining lions and tigers on the endangered species list.
Rabinowitz began his work with the Wildlife Conservation Society and now heads the Panthera Foundation, a conservation group dedicated to protecting the world's 36 species of wild cats. The foundation's current work represents a radical change in Rabinowitz's conservation philosophy from just a decade ago. In the 1990s, having censused jaguars across their range, Rabinowitz and other specialists identified dozens of what they called jaguar conservation units (JCUs): large areas with perhaps 50 jaguars, where the local population was either stable or increasing. At the heart of most of the JCUs were existing parks or other protected areas, which Rabinowitz hoped to expand and secure with surrounding buffer zones. "I felt that the best thing we could hope to do was to lock up these great populations in these fragmented areas," he said.
Within a few years, though, the new science of DNA fingerprinting—studying genetic material to determine family and species relationships—revealed an amazing fact: The jaguar is the only large, wide-ranging carnivore in the world with no subspecies. Simply put, this means that for millennia jaguars have been mingling their genes throughout their entire range, so that individuals in northern Mexico are identical to those in southern Brazil. For that to be true, some of the cats must wander regularly and widely between populations.
Rabinowitz and his colleagues went back to their data to see whether the preserves could still be linked with habitat adequate to support a traveling jaguar. "Lo and behold," Rabinowitz said, "while good jaguar habitat, where the cats can live and breed, has decreased by 50 percent since the 1900s, habitat a jaguar can use to travel through has decreased only by 16 percent. Most of it is intact and contiguous. These places are like little oases—very small patches that jaguars will come to, use a while, and then leave. We were writing these places off because they're not habitat where a permanent jaguar population can live. Now they're turning out to be crucial."