Drones for Watching Beavers and Whales?

Are drones capable of non-evil purposes? Actually, are they even capable of a use that doesn’t make them look creepy and intrusive? (I feel that drone engineers need to do more to make drones that don’t instantly remind me of the Viper probe droid that the Imperial Fleet sent to spy on the Rebel base on planet Hoth.)

There is a surprising application for robotic aircraft that gives me a teaspoonful of hope. In a paper in the Journal of Unmanned Vehicle Systems (a journal whose title will always sound creepy to me) four researchers describe how they used a drone to survey the impacts of a pair of reintroduced beavers on ecosystem structure.

Photo by Per Harald Olsen

Conservationists in the United Kingdom are engaged in a major project of reintroducing the beaver to their country. Overhunting forced the species to local extinction as early as the 16th century. By damming streams and creating ponds and wetlands, beavers make a huge contribution to local diversity. Amphibians, fish, arthropods, plants and more all depend on the habitat created by beavers.

This study observed a pair of beavers brought to a first-order stream in southwestern England. The drone, a hexacopter equipped with a camera, was able to provide good images of beaver activity such as gnawed trees and dams under construction. And with software, the researchers converted these photos to computer models capable of telling us about hydrology, topography, vegetation structure, and other interesting landscape variables.

Unfortunately, the researchers only studied this site after the beavers had done their work, so they weren’t able to make comparisons to how the site was before the beaver engineers got to work.

Nonetheless, what the study suggests will be possible soon is very promising. The drone method is not just trendy. It’s cheaper than piloted aircraft, and, since it is low-altitude, it provides higher resolution data. It’s less labor intensive and faster than doing surveys on foot. You also avoid disturbing sensitive wetlands, which can be harmed by trace amounts of chemicals or pathogens found on researchers. The wildlife themselves are less bothered by a quiet hexacopter than a human or a piloted helicopter. And though the study didn’t mention it, a programmable aircraft is more rigorous than a human observer. Human estimations of vegetation parameters is notoriously prone to error.

Lastly, the drones don’t have a social schedule or a preference for warm or cold weather, and can be kept to inhumane and demanding survey schedules that even a seasoned field biologist would reject.

Another study in the same issue showed perhaps even more exciting benefits to drone surveys of whales. The surveyors launched the hexacopter from small craft at sea, where piloted aircraft would have been expensive and unfeasible. Since the whale pod showed no behavioral changes, the paper concluded that the drone did not bother them. From a height of 35 meters, the drone’s images showed enough detail for the biologists to identify each whale by its markings. And, because the drones can be kept to a constant altitude, biologists can use their photos of whales to calculate precise sizes and track growth rates for each whale.

I would be sad if the advent of drone ecology would mean the disappearance of human-led field surveys. We probably don’t have to worry about that any time soon. The main thing is to celebrate that we have found a socially and environmentally beneficial use for at least a few of those freaky airborne robots.