Drones, wildlife and Science
It’s summer in Antarctica right now, which means temperatures along the coastline are hovering around freezing. David Johnston, a marine biologist at Duke University, and his colleagues have been taking advantage of this balmy weather. Over the past several weeks, they have sent fixed wing and multicopter drones soaring over the shoreline and coastal seas.
“The key thing is to keep the batteries warm before we put them into the drone,” Johnston says. “We use typical hand warmers that you would use when you go skiing.”
The intrepid drones have been spying on penguin colonies and humpback whales. To learn about wild animals, biologists have traditionally flown small planes or helicopters overhead, poured over satellite pictures, or approached on foot. But Johnston and other scientists are increasingly turning to drones to see if they can’t get the job done better and more quickly. “Drones can offer a very safe, green, and inexpensive alternative to manned aircraft,” says David Bird, an emeritus professor of wildlife biology at McGill University in Montreal.
The drones wildlife biologists typically use are small and at the more affordable end of the spectrum. But they can capture detailed photos, or be fitted with thermal cameras or other sensors.
They do have their limitations. Despite Johnston’s success at the bottom of the world, drones cannot handle extreme conditions or be flown over large areas, and may still stress animals out in some cases. “We are still trying to figure out what we can do and what cannot be done with drones,” says Margarita Mulero Pázmány, of the University of Cádiz in Spain and the Technical University of Loja in Ecuador.
They are investigating whether drones can be used to count animal populations and track their movements. Drones may even be able to thwart poachers, explore uncharted or dangerous territory, and get a better-than-ever view of animals going about their business without disturbing them.
The view from above
Humpback whales work together to snare dinner, blowing rings of bubbles to corral fish and krill. Johnston and his team are hoping to observe how many whales are involved in these escapades, whether they play the same roles over time, and how large the bubbles are. “Normally our perspective is from boats and from land, so to be able to actually visualize what they’re doing from above is pretty amazing,” he says.
He and his team brought their drones down to Chile as checked luggage before boarding the boat to Antarctica. “They’re very portable, you can take them all over the place,” Johnston says. In many remote areas, there is no runway, making drones the only way to closely survey animals from the sky.
There’s another big problem with manned aircrafts. “Flying is risky…you can’t do this [research] in a big plane at high altitude, you need to be able to circle and be low to the ground,” says Sophie Gilbert, an assistant professor of wildlife ecology at the University of Idaho. “Things go wrong with small planes.”
In fact, the leading cause of death for wildlife biologists on the job is small plane or helicopter crashes. “Almost all wildlife biologists know of a colleague or a friend who’s died in a plane or helicopter crash, more often than not in the line of duty, of surveying nests or counting animals,” Bird says.
Flying a drone is much safer than climbing into a plane—or clambering up trees and cliffs. “If we want to inspect a nest from a raptor, well, to climb up a tree, it’s always dangerous. So we can use one of these super cheap drones to fly up and take a look,” Mulero Pázmány says.
Plus they’re fast. With drones, scientists can catch drama that they might otherwise miss. “It takes 10 minutes to take off and start gathering data, which is very convenient because there are some phenomena in biology that happen in a very thin time window,” Mulero Pázmány says. She and her colleagues used drones to chart the paths flown by a flock of kestrels in Seville. They discovered that the birds were following the machines that harvest grains. As the harvesters worked, little insects would be flushed out. With drones, the researchers could follow along in near-real time as the birds sought their meals.
“Traditionally we would have to rely on satellites or on aircraft to get the kind of information that we’re getting, and even then it wouldn’t be as high resolution,” Johnston says. “But with the drones, it allows us to be able to go and do this kind of research whenever we want. We don’t have to wait until the satellite pass happens when it’s not cloudy, we don’t have to try to get an aircraft crew together.”
On the other hand, drones have a fleeting battery life and, though they are becoming hardier, cannot operate in wet or windy weather. “You always have to worry about the ocean—salt water and electronics don’t play well together,” Johnston says.
Pushing the envelope
Curious biologists needn’t confine their drones to capturing photos or video. They are devising more creative schemes, too.
Drones could be used to collect microbes from the air to monitor how diseases spread. Drones could fire tranquilizers at animals that researchers want to put ID tags on, or collect samples of hair, blood, and scat. Bird and his colleagues have stuck radio trackers and antennae to drones to pin down signals from songbirds wearing transmitters.
Mulero Pázmány is pondering how drones might be inducted into the Internet of Things to share information with other types of sensors (for instance, if one machine picked up a sudden uptick in pollution, drones might be alerted and fly over to investigate). She and her team have also patented a trap to capture bugs while a drone cruises about. “It’s really difficult to try to sample insects at 200 meters height…by other means,” she says.
It’s also pretty hard to collect identifying DNA from whales, but this too could be a job for drones. When whales surface to breathe, they shoot a mist of saliva, mucus, and air from their blowholes. “There’s a lot of whale DNA in all of that spit,” Gilbert says. “There’s been talk of flying drones through the cloud of whale spit to figure out which whale that is.”
Drones could also be put to practical use, like scanning power lines for electrocuted birds or scaring pests away from crops. They might even spy poachers in the act. In South Africa, Mulero Pázmány and her colleagues have investigated whether footage from drones could be used to detect rhinos, pick out people, and monitor the fences that poachers often slip in through. The drones were useful, but, again, would not be helpful in high winds or heavy rain. Another problem was that, while drones can capture a clear picture of open grassland, footage of terrain covered by dense forests was harder to decipher. And there’s only so much ground that these little robots can cover.
“We cannot just control Kruger [National] Park, which is the size of Israel, with a bunch of small drones that can fly for half an hour,” Mulero Pázmány says. “You can put the eye in the sky, but you need many eyes looking at many places at the same time.”
Still, drones can definitely complement other anti-poaching technology, like cameras planted at ground level and microphones that pick up the sound of gunfire, or the patrols that follow rhinos. Park managers could also publicize that they use drones so poachers are deterred from sneaking into protected areas in the first place. “Drones are not the solution, they are another tool to add to the basket,” Mulero Pázmány says.
Using drones to observe people does also raise ethical question that researchers will have to carefully consider. “If you’re…trying to protect rhinos, part of what you’re trying to do is see people who shouldn’t be there,” Gilbert says. “You really start to run up against privacy concerns and what is too invasive when you start to monitor people with drones.” People who live nearby might not be thrilled about the surveillance, she says.
Another concern is of course safety; drones may crash even when handled by experienced pilots. In many cases, drones will be used to spy on wildlife in sparsely populated areas. “There is no population, so the risk of [it] falling on top of someone’s head is small,” Mulero Pázmány says.
Still, researchers must follow the Federal Aviation Administration’s rules. Even in the uninhabited wilds of Antarctica, drones cannot stray far. “There’s a fairly significant amount of regulation on how we use them,” Johnston says. “We still struggle to be able to fly drones beyond the line of sight or at night.”
This means that, for now, research drone missions are limited in scope, and cannot cover very large areas.
Do not disturb
Wild animals do not appreciate scientists sneaking up on them or flying overhead. Drones could prove to be much less invasive—but scientists are still getting a feel for how much distance a drone should keep between itself and the animals.
Drones are quieter than small planes or helicopters. “But the caveat to that is that we also tend to fly drones a lot closer to animals than we fly manned planes,” says Gilbert, who is planning to use drones to count sea lions and seabirds in Alaska.
The electric whine seems not to trouble the marine creatures Johnston surveys. “It’s very hard for them to detect what we do,” he says.
Still, if an animal is stressed, scientists might not be able to tell just by looking at it. One team flew a drone at relatively low altitudes over four black bears that had been fitted with heart rate monitors for another project. “Their heart rates often went really, really high, which indicates that the drones were probably stressing them out,” Gilbert says.
However, Bird points out, we don’t know how a bear’s heart rate changes if people fly by in a helicopter or walk nearby. So researchers will have to design experiments that involve more animals and compare how they react to drones versus being tagged or counted from manned aircrafts.
Some animals make it easy for scientists to figure out how close is too close. Bird and his colleagues are studying how different birds react to drones. They have sent drones out to count murres, black-and-white seabirds that look a bit like penguins and make their nests in cliffs overlooking the sea. On one occasion, they received an expensive lesson on what happens when a drone doesn’t keep its distance. About 100 yards away from its intended landing site, their drone ran into trouble.
“We heard a very loud thwack, and our rotatory drone started spinning downwards, trying to right itself,” Bird says. As the scientists looked on, the $7,000 piece of equipment plunged into the ocean. “What we surmised was that a gull took exception to it and tried to hit it.”
The drone hadn’t made any friends among the murres, either. Before the machine’s untimely demise, the team learned that the seabirds don’t appreciate a robot zooming past their nests at eye level. When they saw a drone, the birds would bolt off their nests, accidentally kicking out the baby birds or eggs underfoot. Hungry seagulls would then take advantage of the chaos. “They see murres flying off their nests, they come swooping in and get a feast,” Bird says.
So in the future, the team will fly drones at higher altitudes and paint them to resemble another type of seabird. “It’ll basically look like a harmless gannet,” Bird says.
He has also seen that drones can be less disruptive than approaching animals on foot. When scientists wish to take a census of small seabirds called terns, they would normally have to pace back and forth over the colony’s preferred island and count the nests dotting the ground. “While you’re doing that, you’re disturbing the hell out of the birds,” Bird says. “They’re getting off their nests and flying around and crapping on people and pecking their heads so you have to wear hard hats, and people also step on the nests.”
The first time he flew a fixed-wing drone about 300 feet above a colony instead, most of the birds rose up into the air. On the drone’s second pass, only about half of the birds roused themselves. On the third pass very few took flight, indicating they were getting used to the drone.
With drones, wildlife biologists are taking a leaf from the military’s playbook. “A drone is valued for what they call the 3D missions, which is dull, dirty, and dangerous,” Mulero Pázmány says. “Maybe that also applies to conservation.”
Drones can probe terrain not easily reached by people or planes, and quickly and cheaply collect mountains of photos for researchers to comb through. And as the regulations surrounding drones continue to evolve, scientists hope they will expand their reach. “The sooner that we can get regulations that we can all live with, then the more advances we can make,” says Bird, who is working with the US Fish and Wildlife Service to develop permitting procedures for researchers.
Already, drones have observed animals small and large, from pygmy rabbits to elephants. They have mapped out the habitats endangered species such as orangutans rely on, and been used to investigate how diseases might spread.
Scientists are still testing the waters (or rather, the skies) to figure out how best to use drones to learn about wildlife. But the possibilities are dizzying. “I feel like a pioneer who’s on the crest of a wave with groundbreaking technology,” Bird says. “And I can’t walk away from it.”