Le Maho et al, Nature Methods

Studying animal behaviour can be quite tricky: the presence of humans in their habitat can make them nervous, altering how they would usually behave. One solution has been to use robotic rovers, such as the one used for the National Geographic's Serengeti Lion project, but some animals are more skittish than others. To that end, researchers have disguised a remote-controlled rover as a king penguin chick in order to get up close and personal without disturbing the birds.

In order to determine how useful rovers are in studying penguin behaviour, an international team led by Yvon Le Maho at the University of Strasbourg, France, fitted 34 king penguins in Adelie Land, Antarctica -- which are very skittish animals -- with external heart rate monitors that could be monitored using an RFID antenna, which needs to get within 60 centimetres to get a reading.

Next, after the birds had recovered, the team sent a plain, four-wheeled rover into the colony of incubating penguins -- where the males are mostly stationary as they keep the eggs safe on top of their feet. Although the penguins responded with some alarm, squawking and pecking at the rover, they allowed it to get close enough to read their heart monitors, and when the rover stopped moving, their heart rates recovered more rapidly than if a human had entered the colony.

The rover was also able to get close to massive elephant seals, which scarcely seemed to notice the machines.

Le Maho et al, Nature Methods

For emperor penguins, which are very shy, a plain rover wasn't going to cut it, so the team decided to disguise it as a penguin chick. The first version, made of fibreglass, scared the birds. The disguise went through about five iterations before the researchers designed a version that didn't scare the penguins -- one covered in soft fuzz like a real baby penguin.

In fact, the penguins were so comfortable with the disguise that the chicks huddled against it as they do each other, and the adults sang to it, appearing disappointed when it didn't answer back.

This opens up possibilities for studying the birds up close, particularly the effects of climate change on penguin colonies. The rovers could also be adapted to record audio, include cameras, or be equipped with a wider variety of sensors for environmental surveys.

The full study, "Rovers minimize human disturbance in research on wild animals", can be found online in the journal Nature Methods.