A bear may not run when it sees a flying robot swing from the sky – but the animal may still be suffering.
So says a recent study on how black bears in Minnesota reacts to unmanned aerial vehicles (UAVs), also called drones.
In the study, the first to test the physiological reactions of wild animals to UAVs, scientists successfully flew a plate-sized quadruped close to wild bears 17 times.
In almost all tests, the heart rate of the bears – measured by sensors previously implanted in the bodies of the animals – increased significantly, especially when the bear was surprised by the drone. A great acceleration even occurred in a bear that had just gone into its nest to winter.
Unexpectedly, most bears did not act bothered, even as the drone flew within 33 feet (10 meters) of them. The exceptions were two female bears with cubs that ran from the drone, forcing one family to enter the home territory of another bear. (See also “Black Bears Reborn – What That Means For People? “)
In one extreme case, the remote-controlled flyers caused a bear’s heart rate to increase from 39 to 162 beats per minute, a very large 400 percent increase, says a study leader. Mark Ditmer of the University of Minnesota. That’s far above the heartbeat experienced by people riding on a double-corkscrew roller coaster.
“This is a region where bears are constantly exposed to farm equipment noise, roads, traffic; they regularly race through open areas to go from forest fragment to forest fragment,” says Ditmer. “We thought they saw everything.”
But, he says, “Drones have different sounds and different abilities. They can fly under the forest canopy, they can get very close, and even follow an individual.”
Because drones are more common across American skies, for entertainment, trade and conservation projects, scientists are beginning to wonder how they can affect wildlife.
Like the bears, some waterfowl conduct as if free of charge from the UAVs: In a study of half-caught wild flamingos and ordinary vegetable rods, 80 percent ignored the flying intruder, regardless of its color, approach speed, or the number of times it zoomed as close as 13 feet (4 meters).
But in some cases, drones have clearly negative consequences: First, birds sometimes fly into them.
And in May 2014 in Utah’s Zion National Park, a drone caused a flock of great-horned sheep to part“Separate the mothers of calves.” The event, which led the park service to ban the use of drones without special permits, also raised concerns that the robots may be less benevolent than we think.
Protecting Wildlife From Above
Ironically maybe drones are being used more and more to help animals.
For example, they are an excellent tool for monitoring the population of a species and determining its range, and can stop poachers before striking by specifying their locations.
In the not-too-distant future, large and more rugged UAVs could pay attention to poaching vehicles over massively rich natures like the Serengeti. (See “The Serengeti Lion. “)
Meanwhile UAVs can improve efficiency. “Let’s say you’re trying to protect the entire coastal zone from Gabon, “says David Wilkie, the Wildlife Conservation Societydirector of Conservative Support.
“You could do it with just two long-range fixed-wing aircraft constantly flying. And they could be autopiloted by someone sitting in an office in the capital.” (Watch a video on how drones protect orangutans.)
Wilkie adds that it is difficult to interpret the recent study of black bear heart rates.
“It’s unfortunate to use the term‘ stress ’to describe the drones,” he says. “Heart rate is really an indication of excitement, a natural reaction. All animals get excited when there is an unknown sound. It’s about vigilance, not necessarily stress. “
He points out that the heart rates of the study bears quickly normalized after the departure of the drones.
Also, “except for the mothers with chicks I would expect to be more careful of, the bears didn’t move. The faster heartbeat is similar to the bears saying, ‘Hey, what’s that? Strange!’ before engaging in his business. “
For that reason, Wilkie recommends measuring animal levels of the stress hormone cortisol, which could be collected from feces left behind during UAV flights, an effort that would offer additional information that could be more explanatory than heart rate data.
And because many wild animals seem to adapt to human mounts, from helicopters to radio collars, they may be accustomed to drones.
“I have no doubt that these bears, that many species, could get used to UAVs,” says bear director Ditmer. “But if you have an endangered species or animals sensitive to human interference, we could push them beyond a threshold.”
“If there are a lot of UAVs in the future, a sharp strain could become more chronic. And that can lead to a lot of problems.”
For example, he says, chronic stress could affect bears ’reproduction and ability to find food, especially in thin times. Their immune systems could weaken, making them more susceptible to disease.
However, he says, “If there’s a rhino that might otherwise be poached, using a drone to help protect it is probably worth the stress it causes.”
In general, scientists agree that researchers should continue to study both behavioral and physiological responses in wildlife “to ensure that the benefits outweigh the harassment factor for different species,” says Wilkie.
Nowadays long-lasting drones that can carry more sensory equipment can be too expensive for many nonprofit conservationists.
But Wilkie anticipates a future that includes bigger, quieter, more deceptive UAVs doing conservation work that couldn’t have been done otherwise.
“Drones have huge potential that we’ve just begun to exploit,” he says.