That latter feat is one reason some people are less than fond of the jaguar, which, like the mountain lion, has been known to feed on livestock. So not everyone is likely to welcome it back to its former range, although Quigley and other scientists insist that the animal dines mainly on wild prey.
"One individual [animal] in the Southwest is not going to be a concern, but if the population does re-establish itself" it could become a problem, Quigley says. That's one reason the exact location of the most recent sighting has not been revealed.
The two cats seen in 1996, as well as the recent visitor, were all young males and had moved into the area from their normal habitat, which extends about 150 miles south of the border with Mexico. Scientists know the cats were different, rather than one animal that keeps turning up, because the spots, or rosettes, are different. It turns out that you really can tell a cat by its spots.
Quigley says the cat in the most recent photo was young, judging by the fact it had not filled out, and "that would indicate it's probably from a healthy population."
Some of the young male cats stray north after they are "kicked out of the family" by their mother, he says. That suggests the population is robust and growing.
"They start this wanderlust before they settle down in their own territory," he adds. Quigley says he hopes the animals are moving back into a region they once called home, but it's too early to tell. The two cats that were seen in 1996 apparently didn't like what they saw.
"They didn't stay around long," says Childs, who has looked tirelessly for them. "We don't know where they went, of course."
Maybe, with any luck, the latest visitor will decide to settle down here. That would re-establish a colony of animals that you might not want to meet in a dark alley. But as Childs can testify, all you have to do is see one to change your life.
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.