Infrared gets under dragon skin

Bearded dragons are revealing some of the secrets behind their colour-changing ways, thanks to the work of a Melbourne evolutionary scientist.

Devi Stuart-Fox with a bearded dragon. Credit: L’Oréal Australia/

Devi Stuart-Fox has discovered that bearded dragons change colour in response to heat, allowing them to regulate their body temperature.

Her research opens the way for scientists to imitate lizards and develop materials that respond to light and temperature for solar energy, sensor and biomedical applications.

“It’s cool watching lizards, insects and octopuses change colour, but we know so little about how and why they do it. So, we’re working with Australian bearded dragons to understand more about it,” says Devi, a senior lecturer in zoology at the University of Melbourne.

As part of her research, Devi measured the dragons’ near-infrared radiation to understand the mechanism behind their changing colour.

Near-infrared light is associated with heat rather than colour. These wavelengths are invisible to animals, but affect their body temperature.

“These wavelengths are significant because they affect how the lizards reflect or absorb heat. By changing colour in both visible and near-infrared wavelengths, the lizards could simultaneously optimise their camouflage and thermal balance,” she says.

Last year, Devi was awarded her second international L’Oréal For Women in Science honour—the 2013 L’Oréal-UNESCO International Special Fellowship, worth $40,000. Ten years earlier she received a UNESCO-L’Oréal International Fellowship, which supported a study of chameleons in South Africa.

In 2013, her research on colour-changing bearded dragons also earned her an Australian Research Council grant that will fund an international research initiative she is leading.

Photo: Devi Stuart-Fox with a bearded dragon.
Credit: L’Oréal Australia/

The University of Melbourne, Devi Stuart-Fox, Tel: +61 3 8344 4846,