Unmanned Arial Vehicles have been used in a number of ways by researchers studying forest growth, wildlife and habitat loss, especially in areas where the terrain is difficult to access. Researchers from the University of Minnesota published a study in the journal Current Biology that showed the heart rates of bears rose dramatically when a UAV was flown around them. The kind of heart rate accelerations that the researchers recorded indicated the bears were experiencing acute stress.
Mark Ditmer, a post-doctoral researcher in the university’s Department of Fisheries, Wildlife and Conservation Biology and the lead author of the study said in a university press release, “Some of the spikes in the heart rate of the bears were far beyond what we expected. We had one bear increase her heart rate by approximately 400 percent—from 41 beats per minute to 162 beats per minute. Keep in mind this was the strongest response we saw, but it was shocking nonetheless.”
Just how did the team go about getting the data? After all, it’s difficult to get close to bears in the wild. They chose to study American Black bears that normally roam free in the northern and western parts of Minnesota, not an easily accessible area. The bears were fitted with high-tech Iridium GPS collars. Every two minutes, an email containing the location of the bears got sent back to researchers in real time. In addition the bears were fitted with “bio-loggers” that kept track of the bears’ heart rates and other vital signs. Using the location data, the team launched drones into the area where the bears had most recently been and conducted brief five-minute flyovers with the drones.
The data that was collected was very precise given the information provided by the GPS collars and the heart monitors. There were a total of 18 flights conducted. The flights were in the area of four specific bears and while observers were only able to document behavioral changes in the bears during two of the flights, all of the bears involved showed heart rate elevation during each of the 18 flights.
Once the UAVs left the area, the bears’ heart rates returned to normal quickly, and no lasting effects were noted. The team concluded that the use of the bio-loggers was the key to realizing that the drone flights actually did have an effect on the bears, as it was not possible to tell from how the bears were acting that they were experiencing stress.
The University of Minnesota team will now try to make their information part of any regulations or best scientific practices concerning the use of drones in animal research.
Ditmer stated, “UAVs hold tremendous potential for scientific research and as tools for conservation. However, until we know which species are tolerant of UAVs, at what distance animals react to the presence of UAVs, and whether or not individuals can habituate to their presence, we need to exercise caution when using them around wildlife.” His team is now going to work with captive bears to see if the animals can get used to the flights over time.
Check out the video to learn more about this study.