Kristoffer Wild, a PhD candidate, recently published an impressive study on bearded dragons. He conducted his studies at the Bowra Wildlife Sanctuary in Queensland, Australia. In the field trial, conducted over the course of a year, Wild followed 40 different Australian central bearded dragons (Pogona vitticeps). This research focused on revealing their survival dynamics under natural conditions. He released the results of his study in the Journal of Animal Ecology. Together, they expose surprising findings about the life history and killing power of these cold-blooded killers.
The focus of the research was mainly on the feeding habits of bearded dragons. It determined that these lizards are at their highest risk during spring. Female bearded dragons are much more likely to be eaten compared to males. This leads to interesting questions about the male and female survival tactics in these monsters.
To facilitate his research, Wild designed custom jackets for each dragon, enabling him to attach lightweight trackers that monitored various aspects of their behavior.
Innovative Tracking Methodology
Wild painstakingly sewed one-of-a-kind jackets for each bearded dragon. This slick design made it safe for him to attach trackers that weighed roughly as much as an AAA battery. The jackets combined with the trackers tipped the scales at less than 12.5 grams. This figure is about 5% of the adult body weight of a bearded dragon. This careful consideration made sure the tracking devices were not detrimental to their species.
Wild said he’s committed to minimizing any disruption caused by the tracking process. “You do have to tell yourself, ‘Yes, we are manipulating the animals’ behaviour because we’re putting tracking gear on it,’” he stated. However, he added, “We’re trying to minimize [the disruption] at all costs.”
To get the bearded dragons comfortable in their jackets, our process was fast and effective. Wild likened it to dressing a toddler: “It’s like putting a T-shirt on a toddler. You’ve got to fit their head through the shirt, and then you stick their little arms through the holes that you made for them.” He noted that once the jackets were on, the lizards adapted well to them: “Once you get the T-shirt on, they’re totally fine with it.”
Unexpected Findings on Mortality
This movement data, combined with behavioural observations collected from the tracking devices, offered major new insights into the behaviour of bearded dragons. Despite what we used to think, speed doesn’t always help animals survive outside of the lab. Wild’s results indicate just the opposite — the fastest bearded dragons are the ones most likely to die. This unexpected finding upends a long-held paradigm of survival in the natural world.
Martin Whiting, an animal behavioral researcher, who provided commentary on the study. He further stressed the importance of larger sample sizes in order to gain a more complete understanding of wildlife survival. He stated, “We do predict that animals that can sprint faster have a greater chance of surviving in the wild. This is still poorly understood, and this paper helps shake that paradigm a little.”
Whiting elaborated on this complexity in natural selection, noting, “What happens in nature is often not that black and white. There might be systems where being the fastest sprinter is good, like if you’re an antelope and about to be eaten by a cheetah. And then there are other systems where you might need to be more cryptic.”
Implications for Future Research
Wild’s research uncovers critical information about how bearded dragons survive in the wild. It features a snapshot of the exciting new technology that’s transforming animal tracking. Five years ago, the idea of putting GPS trackers and accelerometers on animals as small as a bearded dragon would have sounded far-fetched. Wild noted that making that kind of innovation possible is more practical than ever. “I was talking to somebody the other day, and they’re putting accelerometers on little hatchling turtles to see how much movement they use when they’re hatching out of the nest,” he remarked.
The implications of Wild’s study go far beyond simply having a better understanding of bearded dragons. The research methodology he created might be suited for studying all kinds of small wildlife species. Other scientists are currently finding out how wildlife is acting with new tracking devices. Their goal is to identify strategies for survival and ecological interactions across nested ecosystems from microbial to macrofaunal.
