AUDIE CORNISH, HOST:
National parks have long struggled to prevent theft. Visitors have tried to make off with everything from Native American pottery to civil war relics and valuable fossils. In Arizona, though, park rangers are more concerned about cactus thievery. They're hoping a subtle device will help them put a stop to it. Tyler Fingert from Cronkite News at Arizona PBS brings us the story.
TYLER FINGERT, BYLINE: In the Arizona desert, saguaro cacti crisscross the landscape. They are as common here as the redwoods in Northern California. If you stand next to one of the cacti, chances are it will tower over you. Some of them can grow to more than 40 feet tall and live for up to 200 years. Wisconsinite Jean Gascho was on a recent trip to Saguaro National Park near Tucson, Ariz.
JEAN GASCHO: The saguaros can be quite tall, and it makes you feel really small.
FINGERT: In Arizona, saguaro are protected. You can't vandalize them, let alone steal them. But in fact, they do get stolen, dug right out of the ground.
KEVIN DAHL: It's absolute robbery, and it's absolute criminal activity. And it's for profit.
FINGERT: Kevin Dahl works with the National Parks Conservation Association. He says being a cactus thief can be lucrative. Each one can fetch 100 bucks or more per foot.
DAHL: A mature saguaro in a landscape adds something to the value of the home or the business that's for sale or rent.
FINGERT: To try to prevent theft, the National Park Service has turned to technology. Rangers put tiny microchips in some of their cacti but not many. Of the roughly 1.9 million saguaro cacti in the park, only 1,000 of them are tagged - the ones close to roads and the smaller cacti, those most likely to be stolen. The trackers are similar to pet microchips, but they don't actively broadcast a signal. So if a cactus goes missing, the only way to know if it's from the park is for a ranger to scan the suspect cactus with a specialized reader.
RAY O'NEIL: Our biggest hope is that it's a deterrent.
FINGERT: Ray O'Neil is the chief ranger at Saguaro National Park.
O'NEIL: That people recognize that if they steal cacti from Saguaro National Park, that there's a chance that we're going to be able to identify that that cactus came from the park.
FINGERT: A few cacti thefts may not be noticeable to the casual visitor, but conservationist Kevin Dahl says there was a concern the rolling hills here could forever change.
DAHL: It's a slippery slope. I've been to places where a couple of cactuses went missing and then a couple more. And now there aren't any cactuses there.
FINGERT: The park doesn't have specific numbers on how many cacti have disappeared. They know it's happening, however, because they found holes in the ground where cacti used to stand. For NPR News, I'm Tyler Fingert.
CORNISH: This piece is part of the public media collaboration Elemental: Covering Sustainability. Transcript provided by NPR, Copyright NPR.