Back in the laboratory the researchers found that at lower incubation temperatures these ZZ females produced males, and at high temperatures they produced ZZ females.
Like their mothers, these baby ZZ females also had the potential to lay more eggs than standard females.
Without the production of standard ZW females, these super females could rapidly dominate the population.
The sex determination process in the dragons had changed from one governed by chromosomes to one governed by temperature, the researchers said.
"In the latest study I suggested we should find out what this actually meant in terms of behavior," Professor Shine said.
"To do this my colleague Hong Li, a visiting scholar from China, got to work on standardized observational tests."
RELATED: Pet Bearded Dragons Linked to Salmonella Outbreak
Dr Li studied 115 juvenile and hatchling dragons from eggs incubated at various temperatures.
He found that, when it came to activity and boldness, the 20 super female lizards in the group behaved in an even more male-like way than standard males.
Each lizard was housed in a cage with a container to shelter in and tested to see how active they were, and how quickly they emerged from their shelters (a standard sign of boldness).
"We found that sex-reversed females were much more active than both males and standard females, especially when they were presented with an unfamiliar object," Professor Shine said.
"In the boldness test, the sex-reversed females emerged much quicker from their shelters than the others as well.
RELATED: Reptile Fossils Show Mother Caring for Babies
Professor Shine and his team also found the super females had higher body temperatures than standard females - temperatures more similar to that of males.
"A bearded dragon can have male sex chromosomes but be a functioning female. Yet it can be more male-like in the way it looks, in its temperature and in its behavior. They are more male-like than the actual males," Professor Shine said.
Because super female dragons lay more eggs and because standard females can be bred out of the population, then why aren't all central bearded dragons either males or super females?
"It's a phenomenon that happens at quite high temperatures - we don't know the exact temperature in the nest," Professor Shine said.
"Maybe being bold can be good in some situations. They could get more food. Sometimes it might mean they become easier prey. Either way, it's a strange animal indeed."
SEE PHOTOS: World's Top Heavyweight Reptiles
Original article on ABC Science Online