First Collared Jaguar in the U.S. Euthanized

A mere ten days after researchers collared the first jaguar in the United States, the cat suffered from kidney failure and officials put it to sleep.

“We were very excited to be able to start to identify important areas for jaguars and unlock some of those secrets so we can make better management decisions,” says Bill Van Pelt, Arizona Game and Fish Department’s birds and mammals program director. “It’s just really unfortunate that we’re going to have to continue to speculate on what the jaguar needs really are.”

After reviewing GPS data, the scientists watching the animal’s movements noticed that the cat, named Macho B, hadn’t traveled for three days. When they went to where it was resting to observe it, they saw that he was heavy on his feet and not moving very quickly, so they brought him to the Phoenix Zoo, where veterinarians diagnosed it with kidney failure, a common ailment for older cats.

The veterinarian at the zoo told the Arizona Daily Star that the sedative the researchers used to capture the cat could have hastened the jaguar's demise.

"According to reports, Dean Rice, the Phoenix Zoo's executive vice president and one of two veterinarians to examine Macho B's remains, found the jaguar likely had a kidney condition before his capture. However, the combination of stress from capture and the passing of tranquilizing drugs through the ailing kidney played a key role in his death, Rice said."

When researchers found Macho B in a snare, they had to sedate him before they freed him, says Van Pelt, who has been observing camera trap photos of the jaguar for 13 of his 18 years at the department. The collar was meant to provide researchers and wildlife managers with previously unknown information about the jaguar, like where and how often it crossed the border into Mexico, what it was eating, and how long it remained in one location.

Still, Van Pelt and others who have been working on jaguar conservation for more than a decade remain hopeful that they will continue to learn more about the cats in their northernmost range, despite obstacles to the cats’ survival, like the border fence and habitat loss.

“It’s definitely a tragedy that this has happened,” says Van Pelt. “But we know that he was a territorial male, so maybe he was keeping other jaguars out.”