Like miniature satellites amassing data, drones are forging a new frontier in wildlife research—and saving lives in the process.
Along the California coast, sea lions and cormorants rest as a drone photographs them from above. “Researchers can get data about body size, population size, behavior and health from this new technology,” says drone pilot Shayna Brody. “It’s revolutionary.”
HELLS CANYON ON THE SNAKE RIVER in Idaho is a dangerous place to fly. Crosswinds buffet the airspace, fog rises off the river, and the region is laced with power lines. Yet the Idaho Power Company, which controls the Hells Canyon Dam, routinely flew helicopter surveys through the canyon each autumn to count Chinook salmon nests, or redds, part of their effort to monitor salmon spawning in waters below the dam.
To make the counts, state biologists would look down from the chopper’s open door, taking notes. In 2010, two of those biologists and their pilot died when their helicopter crashed while working on a similar river. Tragically, aircraft crashes are the leading cause of work-related death for wildlife researchers. So Idaho Power biologists Phil Groves and Brad Alcorn started looking for a better way to work.
In 2011, they began testing a hexacopter, a remotely piloted drone with six rotary blades and a camera that could hover over the river taking video. Not only did the drone capture data as accurately as the helicopter survey, but its high-resolution imagery was so good biologists could distinguish between conjoined nests. They could also repeatedly review the drone imagery to extract more information.
These tests were so encouraging that the biologists went to drone-only redd counts in 2016. Traveling by boat and using the hexacopter, they can cover 100 miles of the river and photograph 35 spawning sites in three days, which is faster and more accurate than the old method. And they can fly drones in weather that would have grounded manned choppers. “Safety is the key for why we’re doing this,” says Alcorn. “Not only is it safer, but it’s giving us better data.”
For conservationists who want to work more safely, accurately and economically, drones are becoming an answer. In this fast-growing field, “the sky’s the limit,” says Matt Burgess with the U.S. Geological Survey (USGS) National Unmanned Aircraft Systems Project Office in Denver.
A pioneer in the field, Burgess and colleagues began experimenting with drones in 1998 while seeking a way to spot alligator nests in the Everglades. They eventually developed a battery-powered, fixed-wing drone with a 6-foot wingspan, GPS, internal navigation and video camera. Dubbed the Tadpole, it flew for 30 minutes, sending video to a ground controller. From 2003 to 2006, its missions included surveying wading birds and manatees in Florida, sage-grouse mating fields in Idaho and bison in Montana.
The team then built an even bigger, lighter aircraft with a 40-minute flight time. In 2009, the U.S. Army Corps of Engineers used this new drone to study invasive plants that were choking Lake Okeechobee. The drone’s images were clear enough to distinguish between invasives and natives, allowing managers to target invasives with aerial herbicides instead of broadcast spraying over wide areas. Such targeted spraying is healthier for the ecosystem and “important for fish, invertebrates, birds and other fauna,” Burgess says.
Today, larger fixed-wing and smaller helicopter-style drones are helping transform wildlife and habitat research in some of the world’s most remote and ecologically sensitive areas. Last September, for example, USGS researchers used a small quadcopter drone to survey a huge aggregation of Pacific walruses that have recently begun hauling out at one spot on the northern Alaska coast. Normally, these animals would haul out on dispersed, remote patches of sea ice. But as that ice has melted, some 30,000 to 40,000 walruses now congregate in this one location, raising questions about impacts on the population.
“You have to fly directly overhead to get a good count,” says USGS scientist Chadwick Jay. “The problem is, manned aircraft spook the animals, and if they stampede, they’ll trample young calves.” Using a drone for the first time, the team cited multiple advantages. “Walruses showed no perceptible response to the drone,” says Jay. “We could fly more frequently,” completing 13 counts versus only two or three with expensive, manned aircraft. And “copter drones can hover,” Jay says, allowing researchers to monitor individual walrus interactions more closely over longer periods of time.
Counting birds that nest on the ground has always been a challenge. “If you walk anywhere near ground nesters, you’ll disturb them,” says Victoria Vazquez, coastal conservation program manager for Audubon Texas. To avoid that problem, last May the group tested a quiet, fixed-wing drone for its annual count of ground-nesting waterbirds on Chester Island in Matagorda Bay.
Typically, biologists at his location count the birds from a boat, sometimes standing on a ladder for a better view. Flying at about 150 feet, the drone provided a detailed bird’s-eye view without disturbing the colony. “By studying images made from above,” says Vazquez, “we could even distinguish between royal terns, which have orange beaks, and sandwich terns, with black beaks. It’s a very efficient way to count birds and track changes in the habitat.”
Monitoring habitat is increasingly critical as climate change, invasives and other factors rapidly alter the land—and drones can be a powerful tool in documenting habitat changes. In 2017, for instance, Audubon Texas deployed a drone to survey Chester Island soon after Hurricane Harvey hit. A composite of drone images showed the island had lost 7 acres, knowledge that helped guide placement of sand, shell and other material dredged from the bay.
Likewise, landscape ecologists with the Caesar Kleberg Wildlife Research Institute are using drones to compile 3D models of Texas rangeland to assess the aggressive spread of native tanglehead and invasives such as bluestem, which can degrade quail habitat. Traditional foot surveys could cover just a small area. But with a drone, says ecologist Humberto Perotto, “we can cover 6 or 10 hectares in one flight, then revisit the imagery and map it. It’s huge, and it will help us know which areas to manage.”
One of the most innovative uses of drones is happening at sea. Biologist Iain Kerr of Ocean Alliance pioneered what he fondly calls “the SnotBot,” a quadcopter drone equipped with Petri dishes that flies through whale blow to collect samples for analysis. That blow contains DNA, microbiomes and hormones that provide valuable clues about whale health without the costly, dangerous and invasive process of taking tissue samples at sea.
Researchers from the National Oceanic and Atmospheric Administration (NOAA) use drone photogrammetry to precisely measure migrating whales and other marine mammals, a huge help. Before drones, for example, they measured Antarctic leopard seals by approaching on foot with tranquilizers. “That’s a 1,000-pound animal with a lot of teeth,” says NOAA biologist Wayne Perryman. “If you can measure from the air, it’s a lot better.” NOAA is also using underwater drones, called gliders, that can dive to 3,000 feet and stay on a preprogrammed path for months. Gliders deployed in Antarctica are now measuring chlorophyll, oxygen and krill, a main food source for sea mammals.
For all their promise, research drones are in limited use in the United States because of strict regulations and privacy laws. Non-recreational drone pilots must follow Federal Aviation Administration (FAA) rules and earn an FAA remote-pilot’s license. Domestic drone flights, especially for conservation, must also comply with the Endangered Species Act and Marine Mammal Protection Act, and flights must stay below 400 feet, remain within sight of the pilot and can’t occur at night or in national parks or wilderness areas.
“Researchers have strict guidelines on how to interact with wildlife, but there’s no equivalent for hobbyist drone users,” says University of Idaho ecologist Sophie Gilbert, who uses drones herself. She compiled a list of YouTube videos showing drones harassing animals by flying too close or erratically. Unfortunately, the explosion of affordable, commercial drones, and the appetite for viral videos, have encouraged harassment by operators eager for dramatic shots (see box below).
Hoping to combat abuses, researchers are developing best practices for drone use, noting that wildlife species react differently to drones depending on the sound, shape, distance and angle of approach. A recent study in Current Biology showed that the mere presence of drones caused the heart rate of free-roaming American black bears to jump as much as 123 beats per minute, though the bears seemed unperturbed. “Know the rules, keep your distance and respect all wildlife,” advises Matt Pickett, founder of Eco-Drone, which has developed best practices. “And if an animal turns and looks at your drone, depart the area immediately.”
Globally, drone use in service of wildlife conservation “has grown incredibly fast,” says Serge Wich, a professor of primate biology at Liverpool John Moores University in England and founder of the nonprofit ConservationDrones.org, which uses the technology to map and monitor biodiversity around the world. Since 2011, Wich has worked on at least 20 drone-based wildlife projects that show the promise and potential of drones. Using drones to count orangutan nests in Sumatra, for example, his collaborators spotted illegal logging in a national park and alerted authorities. They evicted the loggers, who were destroying vital habitat for the critically endangered primates.
New applications in Africa also are reducing poaching and human-wildlife conflict. Under the Air Shepherd program, drones—equipped with thermal cameras and allowed to fly at night beyond the line of sight—helped lead to the capture of rhino poachers in South Africa and cut the number of elephants poached in Malawi from 10 or more a year down to zero while the drones were flying, mainly because poachers spread word that someone was watching.
Equally important, Air Shepherd drones are being used to herd elephants away from village crops, cutting down on human-wildlife conflict. And in 2018, the program, working with the University of Southern California, announced the new Systematic Poacher Detector program, which incorporates artificial intelligence to train drones to flag vulnerable species and suspicious activity. “This is a game changer for us,” says Air Shepherd head Otto Werdmuller Von Elgg. “We can help bring an end to poaching—at some point, the risk will be too much for the bad guys.”
In November 2018, a drone video appeared on social media showing a tiny bear cub repeatedly tumbling down a snowy cliffside while its agitated mother paced above, watching as her cub struggled to reach her. The video went viral, but viewers rightly excoriated the drone operator for scaring the animals and putting them at risk. “Drones can provide an extraordinary window into the lives of wild animals,” says NWF Naturalist David Mizejewski. “But operators must act responsibly in ways that don’t disturb wildlife. No picture is worth that risk.”
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