Here, a bearded dragon shows its "I'm threatened" display. The mouth is opened, the inside often flushed with orange, the dark beard flares out in contrast, and there can be a hiss. In captivity they quickly become accustomed to human presence, and the display becomes half-hearted, said one of the study authors Arthur Georges, of the Institute for Applied Ecology, University of Canberra in Australia.
The researchers examined both physical traits and behaviors of the resulting bearded dragon youngsters. To measure the bearded dragons’ level of activity, the scientists looked at how often the lizards bobbed their heads when inspecting a plastic container. How long it took a bearded dragon to emerge from a shelter into an open area was used as a measure of boldness.
Here, a male bearded dragon sits on one of his favorite perches.
Female body, male brain
Here, a bearded dragon shows off his impressive display when threatened.