Animal rights supporters have urged an art museum in the US to call off an upcoming exhibit featuring three tortoises with iPads mounted on their backs.

But the Aspen Art Museum released a statement supporting the exhibit by Chinese-born Cai Guo-Qiang called Moving Ghost Town.

The exhibit opens tomorrow as part of the public grand opening of the town's new $45 million museum.

The African Sulcata tortoises will roam around grass on the museum's roof deck garden.

Each will have two iPads showing footage of abandoned ghost-town cabins from around the valley, images that were previously recorded with the devices while they were attached to the tortoises.

The Colorado museum said the tortoises were rescued from a breeder, a vet is overseeing their care, and that their diet includes leafy vegetables.

The iPads are on mounts attached with an epoxy used to attach tracking devices to wild animals, the museum said.

"It is not the Museum's practice to censor artists," spokeswoman Sara Fitzmaurice said in the statement.

"The three are being closely monitored, cared for, checked by a local veterinarian at regular intervals, and are being exhibited in consultation with the Turtle Conservancy."

She said the tortoises would get new homes after the exhibit closes on October 5.

The Museum also sent a statement from an Aspen vet.

"The iPads have not interfered in any way with their natural behaviour," Dr Elizabeth Kremzier said.

But the creator of a petition to stop the exhibit disagreed.

"These creatures were not designed to carry 2lb iPads," Lisabeth Oden told the Aspen Daily News.