Frill Seekers

Scientists are discovering why our frillneck lizard has one of the animal world’s most dramatic displays.

- John Pickrell

IT’S MOSTLY BLUFF and bluster, but a frillneck lizard’s display when it’s disturbed can still be surprisingly intim-idating. Open-mouthed, with its dinner-plate-sized, bright-red frill erected around its neck like a scaly umbrella, a ‘frilly’ lunges and hisses at biologist Christian Alessandro Perez-Martinez at Fogg Dam Conservation Reserve, on the Adelaide and Mary river floodplains in the Northern Territory.

Between lunges, it sways back and forth and makes loud cracking sounds by whipping its tail. Eventually, it turns and scampers off on its hind limbs to scramble up the nearest tree. “This dramatic performance aims to deter predators, or at least momentarily overwhelm them, so that the frillies can escape,” Christian says. “Even though frillies aren’t dangerous to humans, their behaviour definitely makes you think twice.”

Christian is a visiting researcher in The Lizard Lab at Macquarie University, Sydney, where he’s been working in collaboration with Associate Professor Martin Whiting. He’s been carrying out some of the first field research on these enigmatic lizards, which are common across the tropical savannah and woodlands of northern Australia and New Guinea. Although an adult male here is rarely bigger than 75cm in length and 750g in weight, collecting the data Christian needed on the lizards’ colour and anatomy was more difficult than he expected it to be.

“The frillies would constantly lock eyes with me and frill up, and on several occasions managed to get a good tail-whip to my face,” he says.