As the tourist season gets underway, managers of the wild horses that roam Corolla, North Carolina, are reminding visitors to the Currituck Outer Banks that interacting with the horses can be detrimental to the animals.

More than 100 wild horses in the Corolla herd reside on a 7,500-acre sanctuary in the Currituck National Wildlife Refuge. The nonprofit Corolla Wild Horse Fund (CWHF) manages the horses. Local laws protect the animals from harassment and prohibit visitors from feeding them. CWHF volunteers patrol areas where the horse roam. During the summer the Outer Banks and the wild horses draw between 50,000 and 60,000 visitors each week.

This month, the CWHF has launched a campaign intended to discourage tourists from feeding or otherwise interacting with the horses. The effort includes a billboard that reads, “Admire But Don’t Feed! Apples and Carrots Kill Wild Horses,” a series of commercials on local radio stations, and yard signs bearing the “No Feed/No Approach” message.

“The public is unaware that their snacks are harmful and often cause painful colic and may result in death,” the CWHF said in a written statement. “The strong message is intended to make the public aware that wild horses cannot eat any food that is not from their natural habitat of beach grasses.”

This year’s campaign is just the latest CWHF effort to educate tourists about inappropriately interacting with wild herd. The group launched a similar campaign in 2011 when the consumption of human food was blamed for a wild foal’s death.