Volunteers at Zion National Park recently saw a drone buzzing bighorn sheep in the park./Kurt Repanshek file photo.

Within days of Yosemite National Park officials warning visitors it was illegal to fly drones in the park, volunteers at Zion National Park in Utah say they saw a drone harassing wildlife in their park.

The Zion volunteers say they watched as a remote-controlled drone flew close to a herd of bighorn sheep on the eastern side of the park. They observed the herd scattering at the approach of the drone with several young sheep separated from the adults by the drone, a park release said. Harassment of wildlife within the park is illegal, as is the use of drones.

'œI am sure most people who fly drones have no desire to harm wildlife or endanger our other visitors. Many may not even know that it is illegal to fly a drone here at Zion,' Superintendent Jim Milestone said. 'œWe hope that by educating the public about the reasons behind the restrictions, we will increase their understanding and compliance and help to protect the park.'

According to the park release, "rangers have seen a large increase in the use of drones within the park. Some visitors have complained about drones interrupting the usual peace of Zion'™s soundscape and wilderness, while others have reported feeling unsafe as drones buzz through slot canyons and along exposed trails such as Angels Landing and Canyon Overlook. The recent observation of the bighorn sheep encounter with a drone also demonstrates the negative impact they can have on the wildlife within Zion National Park, particularly in the spring when many animals are caring for their young. In addition to impacting ground-based wildlife, drones may prevent birds from successfully nesting or may cause nests to be abandoned if the birds feel harassed."

A drone is an unmanned aerial vehicle (UAV). Its flight is controlled either autonomously by onboard computers or by remote control. The penalty for using a drone in Zion can be up to 6 months imprisonment and/or a $5000 fine.

'œDrones are a new challenge for Zion National Park and our mission of resource protection,' said wildlife biologist Cassie Waters. 'œAnimals can be injured when attempting to escape or avoid drone activity. Drones can also change the natural behavior of wildlife and lead to unnecessary energy expenditures. This has the potential to affect survival and reproductive success in many species. We are therefore really concerned with drones, their effect on wildlife, and our ability to preserve the natural environment.'