Frill Color Linked with Fighting Abilities for Australia's Iconic Lizard

The Australian frill neck lizard displays its large frills whenever threatened. A new study has found that the frills on the lizard can also be used in its fighting prowess.

Researchers from Macquarie University and The Australian National University looked at the traits that helped a frill neck lizard (Chlamydosaurus kingii) win a fight. They found that while body mass and frill colors both mattered during a contest, a lizard with bright colored frills won about 90 percent of the matches. Having higher mass resulted in the lizard wining 83 percent of the contests.  

Until now, it was assumed that lizards have these frills to ward off any potential predators. Both males and females have them. Researchers of the latest study suggest that the frills may act as a signal to show a lizard's fighting abilities and may help in selecting a sexual partner.

"Surprisingly, traits such as frill size, head size and bite force did not predict contest outcome. Instead, males with brighter and more colourful frills were more likely to dominate opponents and take gold," said Dr Martin Whiting, biologist from Macquarie University, according to a news release.

Researchers also tested the levels of carotenoid pigmentation which gives the frills the characteristic colors of orange, red and yellow. They found a co-relation between a lizard's fighting abilities and the levels of this pigment.

"This is an exciting result because while carotenoids have been the source of considerable study among our feathered friends, we know little about the role of carotenoids in lizards," says Whiting.

The study "Fiery frills: carotenoid-based coloration predicts contest success in frillneck lizards" is published in the journal Behavioral Ecology.