Observing animals in the wild while not disturbing them is a classic challenge for behavioral ecologists. But as a new study shows, the use of remotely operated robots to observe penguins and seals in their natural habitats can result in significantly lower and shorter stress responses.
For the new study, Yvon Le Maho of the University of Strasbourg in France and colleagues sought to find out if remote-controlled rovers could substitute for intrusive human observers. Indeed, efforts to study these sensitive creatures have never been more important. The latest research suggests that global warming will reduce Antarctica's emperor penguin population by nearly 20% over the next 80 years.
To reduce the stressful effects of human observers, the researchers strapped external heart rate monitors to 34 king penguins. These monitors can be read with an RFID antenna.
In the first experiment, the researchers sent an unadorned four-wheeled rover into the colony. Remarkably, the penguins allowed the rover to get close, and their heart rates increased less and returned to normal more quickly than when the same task was performed by a human with a hand-held device.
That said, when a human or rover approached penguins who were breeding, the birds would begin attacking (which, you can't really blame them). However, their maximum heart rate was significantly lower for the rover compared to the human, and more like the heart rate exhibited by penguins when they're defending their territory from other penguins.
In another experiment, they disguised the rover as a penguin chick, which the researchers sent into a colony of particularly shy emperor penguins. The penguin-bot was able to infiltrate the group — and in one case join a creche of chicks. The researchers found that almost half of the adults displayed no reaction at all, while a quarter were sufficiently curious to approach and investigate the strange looking four-wheeled chick.
Similar experiments were replicated on southern elephant seals, who hardly seemed to notice.
"Upon immobilization, the rover—unlike humans—did not disorganize colony structure, and stress rapidly ceased," noted the authors in their study, which now appears in Nature Methods. "Thus, rovers can reduce human disturbance of wild animals and the resulting scientific bias."
In future, similar experiments could be conducted beyond terrestrial populations of seabirds or mammals. Sufficiently adapted rovers could be used in aquatic or aerial environments. And in fact, robotic turtles equipped with cameras recently captured unprecedented videos of dolphins getting high by sucking on puffer fish.
Read the entire study at Nature Methods: "Rovers minimize human disturbance in research on wild animals".
Images and videos: Le Maho et al/Nature Methods