Studying wild animals is crucial if we are to understand why they behave the way they do. But what if the apparently passive act of observation changes the way they behave? For decades, behavioural ecologists have been very mindful of this problem. A paper, just out in Nature Methods, suggests a cunning new way to collect data from wild animals without causing them undue stress.
There are many ways to study the behaviour of wild animals. You can go out and gain their trust, hoping they get so comfortable with your presence that they carry on as if you weren’t there at all. Or you might want to fit your study population with some kind of gizmo that can collect (and maybe even transmit) data in your absence. But even devices like these are likely to alter behaviour: increasing drag, for instance.
A microchip implanted beneath the skin (as is now routinely performed for pets) is much more likely to go unnoticed by the animal. The snag is that in order to scan the chip and identify the individual, you have to get pretty close. Researchers have now come up with an alternative: sending in a remote-controlled robot equipped with a scanning device, the ability to collect all sorts of data on the focal animal and then transmit it into the ether. Testing this method out on king penguins, they reveal that it is likely to be a whole lot less stressful for the animals.
When approached by a human, for instance, a penguin’s heart rate increased by an average of 35 beats per minute. When the rover came at it, its heart rate also increased, but only by around 24 beats per minute. In addition, a human caused the target penguin to move much more (average of 43 cm) than the rover (just 8cm). With the robot, the penguins were also much quicker to return to their original physiological state.
The researchers went on to see if emperor penguins had a similarly relaxed reaction to robots. Many were wary. But when the scientists dressed up the rover as a baby penguin, everyone was happy. “Chicks and adults were even heard vocalizing at the camouflaged rover, and it was able to infiltrate a crèche without disturbance,” note Yvon Le Maho and colleagues.
This set-up is obviously not going to be workable in every setting. But it certainly does open up a lot of exciting possibilities for students of animal behaviour. Not to mention some rather wonderful photographic opportunities.
