10 Surprising Bearded Dragon Facts

Bearded dragons are the most commonly kept pet lizard, and they have also become a quiet favorite of laboratory science. Some of the strangest things known about them came out of sleep labs, genetics labs and animal cognition studies.

1. They have a third eye. On top of the head sits the parietal eye, a small pale scale over a light-sensitive organ. It cannot form images, but it tracks light and helps set daily rhythms. In one experiment, dragons reacted to a weak electromagnetic field only while that eye was uncovered and only under light below 580 nanometers, which points to a light-dependent magnetic sense. That light-first biology is also why a dragon kept without proper UVB lighting goes wrong so quickly.

2. They darken on purpose to warm up faster. Wild dragons change the color of the back with body temperature, going dark when cool and pale when warm. Researchers modeled the payoff at about 22 minutes less basking per active day, or roughly 85 hours across a season. The beard and chest change color for social reasons instead, so one lizard runs two separate color systems.

3. A hot nest can turn a genetic male into a female. Bearded dragon sex is set by ZZ and ZW chromosomes, but high incubation temperatures override the genes and ZZ males hatch as fully functional females. Sex-reversed females have been found in the wild, the first time this was shown in any reptile outside a lab. Some lizards skip the chromosomes altogether and let temperature decide from the start, the way the leopard gecko does.

4. They have REM sleep. Brain recordings showed dragons cycling between slow-wave and REM sleep all night, the pattern once thought to belong to mammals and birds. Their cycle runs about 80 seconds, against 60 to 90 minutes in humans. If dragons have it, REM sleep probably dates back at least to the common ancestor of reptiles, birds and mammals, about 320 million years ago.

5. They can learn by watching. In a trap-door test, dragons that watched another dragon open a door to one side opened it to the same side. Dragons that saw the door move with nobody pushing it failed. It was the first evidence of imitation in a reptile, an ability once thought to belong to humans alone and later found in mammals and birds.

6. They wave at each other. That slow arm wave is a form of communication. It can be a submissive gesture or a way of saying hello without starting a fight.

7. Their beard is a display. A threatened or dominant dragon puffs out and darkens the throat pouch to look bigger.

8. They see into the ultraviolet. Their vision extends past the violet end of the spectrum that humans can see, which is part of why they respond so strongly to certain lights and colors.

9. They come from arid inland Australia, where they are good at holding on to water and get much of what they need from food.

10. They can live a long time. Ten to fifteen years is typical in captivity with good care.

The third eye thing still weirds me out a little, honestly. Which fact caught you off guard? Tell me in the comments.

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