How do you get to hang out with penguins and elephant seals without raising much of a fuss? Let a rover be your guide.
In the ongoing quest to understand and conserve wildlife, researchers need to collect data on species for science and management goals. But humans and animals don’t mix very well in the wild, and getting information can cause a great deal of stress to individuals and populations. The presence of people can be so disturbing to animals that it even biases the data scientists are trying to collect.
Wildlife researchers are well aware of this problem and many are turning to new technologies to get a glimpse of animals while minimizing interference in their lives. Some are using drones, DNA and satellites to monitor species movements and thwart poaching. Others are deploying autonomous tools like camera traps and undersea gliders to better understand how and where wildlife operate in their habitats. Now, a group has shown that little rovers can bring the animal world closer while less significantly changing the behavior of the creatures being studied.
“Approaching wild animals to collect data on their phenotypic traits induces stress, escape behavior and, potentially, breeding failure and therefore jeopardizes the quality of the collected data,” an international team writes in a study published today in the journal Nature Methods. “Even after habituation, human approaches and manipulations induce near-instantaneous, large and long-lasting increases in stress hormones.”
In an attempt to overcome this problem, the group has shown that small robotic rovers investigating breeding king penguins cause the animals less stress than if a human had come plodding along. The scientists equipped their rover with a sensor that could read radio-frequency identification tags, which had previously been implanted in some of the animals and can only be read at close range. Researchers commonly gather information on specific animals using RFID tags that identify individuals and assign their location GPS coordinates. Over time, this data log becomes an important record of animal movement and behavior.
To see whether a person carrying an RFID reader or a remotely controlled rover equipped with the reader caused penguins more stress, Yvon Le Maho from the University of Strasbourg in France and colleagues outfitted 34 king penguins with heart-rate monitors to measure their stress response when either came close. Heart-rate readings showed a significantly lower response to the little rover than an approaching human. They also camouflaged the rover with a toy in the shape of a baby king penguin. They found that this disguise allowed the rover to get close enough even to shy penguins to read their RFID chips.
(The rover was able to infiltrate the emperor penguin crèche without disturbance, thus demonstrating the possibility to use such a camouflaged rover to collect data from locations within a colony that are not accessible to a human investigator. Courtesy Nature Methods/Le Maho, et. al.)
“When approached by a remote-operated vehicle (rover) able to make radio-frequency identifications, wild penguins had significantly lower and shorter stress responses (determined by heart rate and behavior) than when approached by humans,” they conclude in their paper. “Upon immobilization, the rover—unlike humans—did not disorganize colony structure, and stress rapidly ceased.”
More success came from the rover’s interaction with nearby lounging elephant seals. The unit approached the animals’ heads and tails without disturbing them, an action that, if done by a human, would cause a great deal of stress.
They say this work shows that rovers could also be used in aquatic or aerial environments to collect data from a range of animals with less bias introduced by the collection method. Such unmanned vehicles could also be equipped with more advanced instruments to provide more streams of information, like recordings of animal vocalizations or other important data.
All gifs: The rover approaching king penguins and southern elephant seals on a beach. Gifs created from video courtesy of Le Maho, et. al.
Top Image: Brooding emperor penguin with its chick approached by a rover camouflaged with a fake chick. Courtesy Nature Methods/Le Maho, et. al.