May–June 2021

Flight Plan

Drones can be high-tech helpers in the natural resource world, but they also pose potential threats to wild places and wildlife. The DNR is preparing for both scenarios.

Emily Sohn

The moose stands knee-high in a serene Canadian lake, as still as the calm water. Suddenly, the powerful creature startles as a wolf emerges from the forested shore. The wolf dives into the lake and beelines for the moose. The moose stomps at the wolf. The wolf darts back and forth, each time getting closer. Eventually, the moose swims away from the wolf, which chases it, then spins around to fight again. The battle lasts for several suspenseful minutes—and the only reason the world knows about it is because it was captured by a video camera attached to a drone. 

Along with footage of migrating dolphins and the inside of an active volcano, the moose and wolf video—which has been watched more than eight million times on YouTube—illustrates the potential for drones to provide an unprecedented window into the outdoors, and not just for ogling at nature. Increasingly, experts are turning to drones for scientific research, law enforcement, rescue operations, and more. 

But drones are also opening up a can of worms when it comes to the potential for conflict, says Chris Lofstuen, chief pilot for the Minnesota Department of Natural Resources. The tiny flying objects can get in the way of other aircraft, interfere with firefighting, and threaten the safety of pilots. Drones can also disturb wildlife and intrude on people’s wilderness experience. 

The potential uses—and potential harms—of drones are fueling an intensive process at the DNR to create a program that would plan, oversee, and regulate drone projects through the department. Alongside guidelines under development at the Federal Aviation Administration, the National Park Service, the U.S. Forest Service, and other agencies, the goal is to be deliberate about maximizing the benefits of drone use while minimizing risks. In the coming years, Lofstuen says, drones could become routine tools in DNR efforts to survey animals, control wildfires, and inventory wetlands, among other tasks now done mostly with helicopters and small airplanes. The tricky part is figuring out how to safely collect and store data while regulating the use of a rapidly advancing technology that is exploding in popularity.

“Potential DNR users may think—because their kids have an iPhone drone and it’s pretty easy to fly—‘Hey, what a great tool,’” Lofstuen says. But there are downsides, too. “It opens such a Pandora’s box. You need to really be ready for it.”

Flirting With Fire. To legally operate a drone that weighs more than half a pound in the United States, users need to register devices, which are technically called unmanned aircraft systems (UAS), with the FAA. As of March 2021, more than 868,000 UAS users were registered, with  almost 500,000 of them signed on for recreational use. The rest had registered for commercial uses, such as photography and mapping. 

Whether someone is flying a drone for fun or for work, FAA rules require that unmanned aircraft be flown below 400 feet and stay in the line of sight of the operator. If the drone is used for commercial purposes, users in Minnesota must also register their devices, pay state taxes, and have insurance. Recreational drone users are exempt from state-level tax, registration, and licensing. Some local communities, too, have instituted noise and hazard ordinances that apply to drones.

Public lands have their own rules. Drones are not allowed to take off, land in, or fly through congressionally designated wilderness areas, including the Boundary Waters. The U.S. Forest Service allows drones on other forest lands but urges users not to fly over wildlife or launch drones within 100 meters of wild animals. Most national parks ban drone use by visitors. Permits are required for researchers and filmmakers who want to do work with drones in national parks. It is illegal to operate drones in national wildlife refuges, including all 13 of Minnesota’s.
On a state level, it is against the law to land drones in Minnesota state parks, recreation areas, and green spaces on roadsides. Drones can legally be flown over these lands if they remain in the operator’s line of sight and land elsewhere, but the DNR discourages such flights. Drone flights are allowed in state forests, but the DNR discourages those, too. Drone use is also discouraged in state scientific and natural areas and wildlife management areas. 

Agencies communicate regularly, and guidelines are continually updated in response to growing use and changing needs, says Dirk Giles, UAS program manager at the U.S. Forest Service in Boise, Idaho. Official policies are still a work in progress, but the Forest Service urges people to contact them if they are using drones commercially on public lands. “So, if something does come around, we can communicate with them and say, ‘Hey, we need to deconflict. We’re going to be flying a helicopter in this area,’” he says. “These are best practices, and best practices turn into standards eventually.”

Despite multiple regulatory layers, states can’t enforce federal laws, and drone users don’t always know about all the rules. Drones have been involved in plenty of dangerous situations and near misses. Since 2016, drones have interrupted at least one firefighting effort in Minnesota nearly each year, according to the Minnesota Interagency Fire Center, even though it is illegal to fly a drone near a wildfire. During a fire in central Minnesota’s Little Falls area in April 2018, a DNR airplane pilot spotted an object flying above a firefighting helicopter. He thought it was a bird before realizing, based on its flight pattern, that it was a quadcopter drone. The helicopter landed to avoid the potential for collision. Police came to the scene but couldn’t find the drone operator.

No one was hurt, and the fire was already under control, but it was lucky the pilot spotted the drone at all. The scenario could have ended with a catastrophic crash, says Darren Neuman, DNR wildfire aviation supervisor. In California, drones have grounded firefighting helicopters several times during critical moments in efforts to suppress wildfires. There has been at least one collision. It’s only a matter of time, experts fear, before a drone causes a fatal accident during a firefighting operation.
Flying a drone near a fire, “The pictures you get could be amazing, but what you’re putting at risk is too important,” Neuman says. “Prior to our fire season in the spring, we try to get the word out that it’s unsafe for our pilots. For their safety, please stay away from smoke.”

Given the rapid rise in drone use, “At some point, something really bad is going to happen with a drone,” adds Daniel Heins, UAS coordinator at the University of Minnesota’s Remote Sensing Lab and Department of Forest Resources. “It’s odds and statistics.”

Even when drones don’t threaten lives and expensive equipment, they can be annoying. In wild spaces, people regularly complain about drone noise, according to the National Park Service. Drones have crashed into Yellowstone geysers, tried to land on Mount Rushmore, and disappeared over the edge of the Grand Canyon. At places like Gooseberry Falls State Park, Heins says, people often get around rules by launching their drones outside of park boundaries and then flying in to take pictures of the waterfalls. These types of activities, some experts worry, can become real problems when they involve wildlife.

Animal Crossings. Three bobcats sit on the frozen St. Louis River near Duluth. Occasionally, one scurries around, but mostly they remain still and stare directly at the camera, which is capturing the scene from a hovering drone. The winter sunset tints the sky pink in the background. The music is playful. And the animals look like adorable house kitties as they watch the drone to see what it will do next. The footage is hard to look away from, and many people didn’t. Since it was posted on YouTube last December, the video has drawn more than 180,000 views.

But backlash soon followed, and the amateur videographer apologized—adding the Midwestern bobcats to a long and growing list of controversial encounters between drones and wildlife. In 2018, a drone video of a mother grizzly and her cub on a steep and snowy slope in Russia sparked criticism, as the mother stared down the drone while the baby slipped and slid. Onlookers speculated that the drone may have nearly caused a tragic fall.

There is some evidence to support such concerns, says Mark Ditmer, a wildlife ecologist at Colorado State University who is based in St. Paul. As part of an early project to investigate the effects of drones on wildlife, Ditmer and colleagues flew a drone close to several black bears in northwestern Minnesota in 2014. The bears, which were equipped with cardiac monitors, didn’t move much in response to the drones. But every time the devices flew by, their hearts beat as much as 400 percent faster, found the study, which was a collaboration between the University of Minnesota, Medtronic, and the DNR.

“They pretty much stood still, but their heart rate spiked like crazy, which is suggestive of a major stress response,” Ditmer says.

Even if an animal seems calm around a drone, the study suggested that recreational drone flying can be stressful for them, especially when drones get too close. And that kind of stress appears to happen a lot. “You can go on YouTube,” he says, “and find tons and tons of videos of people using drones inappropriately around wildlife.”

Subsequent research has offered a more nuanced view. When Ditmer and colleagues flew drones over captive bears at the Wildlife Science Center in Stacy they again recorded heart-rate spikes in the animals. But with each successive flight over the following weeks, the bears reacted less until they got used to the flying objects. Even after a several-month drone break over the winter, the animals seemed to remember their past experiences, and their hearts remained steady when the drones flew by in the spring. In another study that was recently accepted for publication, University of Minnesota Duluth graduate student Michael McMahon flew drones equipped with thermal imaging sensors over moose populations on the Grand Portage Indian Reservation in far northern Minnesota. The sensors were able to detect GPS-collared moose and their uncollared calves with no evidence that the drone disturbed the animals or affected their behavior, says McMahon, who collaborated with Ditmer and others on the study.

“The moose found no reason to be afraid of the UAS because it was not directly harassing them,” McMahon says. “We believe that our research shows great promise for UAS and thermal sensors to be used in wildlife surveys.” 

For scientists, Ditmer says, drones could become an increasingly valuable tool for collecting fine-scale data more efficiently than they have been able to do with other methods. In the Cedar Creek Ecosystem Science Reserve in East Bethel, near the Twin Cities, Ditmer and colleagues used drones to count deer and came up with population estimates that were comparable with those acquired with traditional strategies, like using camera traps or counting poop pellets. They’re also collecting data on vegetation and habitat to understand animal behavior.

In southwestern Minnesota, drones used thermal imaging to efficiently find newborn white-tailed deer fawns in wildlife management areas in a pilot project by DNR researcher and University of Minnesota PhD student Tyler Obermoller. The equipment was so sensitive that it detected animals as small as mallard ducklings, Obermoller says.

Compared with photographs taken from airplanes or satellites, drones can get images with better resolution, often in less time, and without having to rely on government agencies for data, says the U of M’s Heins. He has used drones to monitor forests, wetlands, dams, and other landscape features around Minnesota. Drones, he says, can provide information about how high the treetops are and how many board feet of wood are in tree stands.

“It’s those heightened inventory metrics that allow the DNR then to manage their forests better,” he says. If regulations eventually change to allow researchers to fly drones beyond their line of sight, he says they could revolutionize science and work at the DNR.

Technological advances—such as longer-lasting batteries, broader transmission ranges, and location-transmitting technologies—will make even more applications possible with fewer risks, the DNR’s Lofstuen adds. Even though drones can annoy people and animals, he says, they are often quieter and less intrusive than the helicopters and airplanes that researchers already use to monitor forests and species. And they can be mobilized more quickly and in worse weather.

Deeper Into Drones. Given the possibilities, the DNR pulled together a team to consider the use of drones in the agency. Starting in 2018, the group consulted with contractors who have operated drones on collaborative projects with the DNR. They also consulted with the Minnesota Department of Transportation, which has an established drone program. One goal was to reconsider current operations. As it stands, anyone in the DNR who wants to do drone work needs to submit a request to Lofstuen, who checks insurance, liability issues, costs, and other details.

With drone use becoming more common in the public and private sectors, the DNR has identified multiple ways that drones could help with the agency’s work. Among them: finding and fighting wildfires, surveying damage after natural disasters, finding people lost in the woods, conducting wildlife surveys, and making videos of recreational opportunities for DNR websites. Many of those applications have already been tested successfully in pilot projects.

Given the significant promise and manageable perils of the technology, the team concluded that it is time for the DNR to establish an in-house drone program with a designated coordinator. The program would plan, operate, and oversee projects and would manage the mountains of data that drones can collect.

Doing it right will require working out a lot of details, including financial ones, says Jennifer Corcoran, remote sensing program consultant at the DNR.

“We want to make sure we’re spending money the right way, using drones in situations where they’ll be most useful, training people correctly, and following all local and federal laws,” she says.

The proposal will next be considered by department leadership, Lofstuen says, though timing is uncertain, given pandemic delays. Once the program is in place, there will be a lot to do.

“We’ve gotten to that point where there are enough good reasons” to build a drone program, Lofstuen says. “As chief pilot, I don’t think drones will ever put our unit out of business. I think there are some really good uses for drones.”