New research that monitored the behaviour of Australian central bearded dragons via tiny fitness trackers has revealed a surprising twist – the fastest lizards were most likely to die than the slower ones.
Published today in the Journal of Animal Ecology , the research – led by University of Melbourne Dr Kristoffer Wild – studied the bearded dragons ( Pogona vitticeps ) in their natural environment over the course of a year while they wore small, high-tech devices on their backs.
The lizard-friendly ‘wearable smart devices’ contained tiny accelerometers and temperature-sensing radio transmitters to feedback data on the lizards’ body temperature and acceleration.
Like other cold-blooded reptiles, bearded dragons rely on external heat sources to regulate body temperature to grow, digest food and reproduce effectively.
“Our study confirmed that these dragons are indeed masters at optimising behaviour according to seasonal shifts in air temperature,” Dr Wild said.
“Data showed the lizards strategically moving between sunny spots and shady retreats in a delicate balancing act called behavioural thermoregulation.”
Then, a surprising find.
According to Dr Wild, the twist came when the research team looked at the dragons’ optimal temperature for achieving peak speed and how speed related to survival outcomes. Peculiarly, the data showed that lizards with higher speeds had a greater risk of mortality.
“What we believe is happening is that speedy lizards are engaging in riskier behaviours, such as moving around more openly and frequently, making them vulnerable to predators like birds and cats,” he said.
“We found that increased risk was especially pronounced during spring, so this would make sense with dragons moving around a lot more looking for mates.”
While it’s typically assumed “the faster the better” in animals’ survival, these findings flip this assumption on its head. Being too speedy may, in fact, put these lizards at risk to predators.
“These findings highlight an important ecological reality – what is measured in controlled lab environments doesn’t always reflect what is happening in real-world environments,” Dr Wild said.
“This research reminds us that in the wild, survival isn’t just about physiology, but is deeply intertwined in the interplay with behaviour, predation risk and environmental variability.”
Journal of Animal Ecology
Observational study
Animals
Thermal performance curves, activity and survival in a free-ranging ectotherm
16-Jul-2025