GRAND CANYON NATIONAL PARK, Ariz. (AP) — Grand Canyon National Park says it will increase surveillance for a fungus that spreads rapidly among bats and can kill them.

The park has been sampling bats and bat droppings for years and hasn't found any infected with white-nose syndrome. Testing earlier this year on a fringed bat came up inconclusive for the fungus that leads to the disease, which biologists say could mean it's arrived at the Grand Canyon.

The park says it will increase surveillance for the fungal disease this winter and spring to better understand any movement in the Southwest.

Grand Canyon wildlife biologist Brandon Holton says white-nose syndrome tends to show up in bats a few years after the fungus is detected. Infected bats have visible, white fuzz on their nose, ears and wings.

The park is home to 22 bat species, 12 of which are more susceptible to the fungus because they hibernate in the winter.

Holton says infected bats shed the fungus in the spring when they emerge from hibernation. Some infected bats die of starvation because they're more active and use up fat reserves.

The National Park Service says bats do not transmit white-nose syndrome to humans.

Wildlife officials say visitors should let rangers know if they see any sick or dead bats at the Grand Canyon. The park's Cave of the Domes is open to tourists.