Remote-operated vehicles (rovers), which can be used to monitor penguins and other wildlife in their natural habitat, have less of an impact on animal behavior than humans do, reports a paper published online this week in Nature Methods.
Approaching wild animals to collect data can lead to stress and escape behavior for animals, and jeopardizes the significance of results for researchers. How to study animals in their natural environment while minimizing human disturbance remains one of the methodological challenges in ecology. One current tool for such studies is to tag animals with Passive Integrated Transponders (PIT-tags), which have Radio Frequency Identification (RFID) that can monitor individual animals at a population scale; however, PIT-tags can only be read when the animal with the tag is close to an antenna.
Yvon Le Maho and colleagues examined the feasibility of reducing stress on incubating king penguins by using a rover as an antenna to read RFID tags. They found that stress responses (heart rate and behavior) of these penguins were significantly lower and shorter in duration when the rover approached them, compared to when human researchers approach. In addition, when the rover stayed still, it ceased to disorganize colony structure, and heart rate and behavior rapidly returned to normal.
The authors also camouflaged the rover with a penguin model and tested it on the more shy emperor penguins. They report that the emperor penguins allowed the rover to approach close enough to read RFID tags; some chicks and adults even vocalized at the camouflaged rover. Preliminary research with southern elephant seals demonstrated that they allowed the rover to approach their heads and their tails-something that humans have not been able to achieve without significant reaction from elephant seals. The authors suggest that rovers may prove a less invasive and stressful way to collect data on these species, and may be adapted in the future also for uses beyond electronic identification of terrestrial birds and animals.