F is for Frilled Neck Lizard

The Frilled Neck Lizard (Chlamydosaurus kingii) is yet another Australian species makes it onto the list. It is also commonly known as the Frill Necked Lizard.  Confusing, I know.  As I'm sure you've guessed, it's name comes from the large frill around it's neck.  It uses this flap of skin when frightened.

It will open it's mouth (yellow on the inside), extend the frill, stand on it's two hind legs and hiss at the threat.  If that doesn't do the job, the lizard has no issue with running in the opposite direction, still with mouth open, frill out, and on two legs.

The frill is also used in competition for mates and territory, and possibly for heat regulation.  The lizards live in tropical and warm temperate forests and woodlands.  They actually spend most of their time living in the trees, occasionally coming down to hunt out some food, such as ants, termites, small mammals, and small lizards. 

The lizards exhibit sexual dimorphism, or physical differences between sexes.  Females can lay between 8 and 23 eggs into underground nests.  Frilled Necks follow in the footsteps of many other herps in that their sex is determined by temperature (TSD).  High and low extreme temperatures will produce females and medium temperatures will produce males.  Pretty cool!