Feb. 21, 2002 -- It took 4 ½ years to get it, but the rare photo Jack Childs captured near the border between Arizona and Mexico was well worth the wait. His automatic, motion-sensing cameras snapped hundreds of photos of virtually everything that moves in the deserts of the Southwest, but in January he finally got his cat.

There, slinking across the desert in the dark of night, was a wild jaguar, one of the most powerful animals in the world, and a rare visitor to the United States.

"Everybody said I'd never get it," says Childs, a retired land surveyor turned wildlife researcher.

The picture of the jaguar was precisely what Childs was after, because scientists believe there is a chance that the exotic cats might be attempting to "recolonize" the southern part of the United States. They were never there in great abundance, but jaguars used to roam across southern Arizona, New Mexico and even Southern California and Texas, according to Howard Quigley, director of the Wildlife Conservation Society's Global Carnivore Program, which is funding Childs' photographic efforts.

Childs has been using 10 cameras at different sites in southern Arizona, and he will soon expand that number to 16. But just like the princess who had to kiss a lot of ugly frogs before finding her prince, Childs wound up with boxes full of bad photos before he got the one he was after.

"We've got pictures of everything that lives in this country," he says. "Wild pigs, mountain lions, black bears, bobcats, a gray fox, and even illegal immigrants, dope smugglers and backpackers." So far, he says, none of the humans captured on film have swiped any of his gear.

‘A Mystical Experience’

Childs' jaguar was the first photographed in North America in about six years. There were two other confirmed sightings in 1996, both by hunters who were looking for mountain lions.

One of those hunters was Childs.

"I was lion hunting with my hounds," says Childs. "I thought I was chasing a mountain lion, and it turned out to be a jaguar."

The sight of the huge yellow cat, renowned for the black rosettes that distinguish it from other cats, set Childs on a different course. He contacted the Wildlife Conservation Society, headquartered at the Bronx Zoo in New York, which funded his efforts to get a handle on how many jaguars are in the area.

The proposal had special appeal to Quigley, a wildlife biologist who has studied jaguars and other cats all over the world.

Quigley knows firsthand what it's like to see one of these animals in the wild.

"It's the kind of thing you take with you for the rest of your life," says Quigley. "It's kind of a mystical experience."

But seeing one is extremely difficult, as evidenced by the fact that it took Childs more than four years to capture a single photograph. And it could get a lot harder. The U.S. Fish and Wildlife Service recently added the jaguar to the Endangered Species List, so their numbers are not great.

Reasons for the jaguar's decline range from lost habitat to competition with other species — including humans — for its food. Seems we both have a taste for venison, and even wild pigs.

A Really Big Kitty

The jaguar is the largest of the New World cats, ranging up to 8 feet in length and weighing up to 250 pounds.

It is an especially powerful beast, capable of dragging a cow across the ground.

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.