According to a report from the Australian periodical New Idea, the couple want to preserve their 16-acre property outside of Nashville. Kidman was close friends with animal advocate Steve Irwin before his death in 2006, and wants to help continue his legacy in her own backyard.
"It was Nicole's idea to create the wildlife sanctuary for their girls," says Kidman's friend Bobby Saucier, who manages the Nashville-area store and restaurant, Puckett's Grocery. "She liked what the Irwins did for Bindi."
The couple own an expansive $3.5 million farm in Leiper's Fork, a small town located just south of Nashville. The property is reportedly home to an array of wild animals, including horses, cows, deer and pigs. Although Urban and Kidman spend most of their time in their mansion in metro Nashville, the pair see the farm as a true refuge for their family.
"Keith and Nicole want their girls to appreciate nature and animals," Saucier explained. "I think they'd love to live here full-time if they could."
The business owner says the couple also appreciate the small-town atmosphere, which allows them to be out and about without being harassed by fans or paparazzi.
"When they come here, they're treated just like any other normal family," he says. "They love it because Keith can just put his baseball cap on and be treated just like any other country guy in these parts."
It's unclear if Kidman and Urban have an specific plans to make their property a full-time residence, but it seems likely that the pair will use the property to help instill a love of nature in their two daughters.