11 Surprising Facts About Komodo Dragons

These giant lizards are fast, venomous, and dangerous, but also surprisingly playful.

6 illustrated facts about komodo dragons, including that they play

 Treehugger / Catherine Song

The Komodo dragon is the largest lizard living on Earth today, growing up to 10 feet (3 meters) long and weighing 150 pounds (68 kilograms) or more. Yet while this enormous reptile may not fly or breathe fire, the term "dragon" is less of a stretch than it may initially seem.

These are incredible creatures, and they don't need flight or fire to be worthy of our awe and admiration. Here are a few interesting facts to shed some light into the strange world of Komodo dragons.

1. Komodo Dragons Are Originally from Australia

While famous for being from the Indonesian island of Komodo and surrounding islands, the Komodo dragon started off in the Land Down Under. According to fossil records, Komodo dragons (Varanus komodoensis) moved out of Australia and made their way to the Indonesian islands, arriving on the island of Flores around 900,000 years ago.

As researchers noted in a 2009 study in the journal PLOS One, Komodo dragons may have disappeared from Australia around 50,000 years ago, a disappearance that would have roughly coincided with the arrival of humans to the continent. The lizards also has disappeared from all but a few isolated islands, and the species is now listed vulnerable to extinction by the International Union for Conservation of Nature.

2. They're Venomous

It's only recently that Komodo dragons were discovered to be venomous.
It's only recently that Komodo dragons were discovered to be venomous. Luca Vaime/Shutterstock

For a long time, it was believed that a Komodo dragon's bite was so dangerous because of the massive amount of bacteria thriving in its mouth. As a scavenger beast, its bite must be filled with the deadly microorganisms of rotting flesh and would infect and kill any victim.

The truth, however, was discovered by Bryan Fry, a venom researcher at the University of Melbourne in Australia, who found that the Komodo dragon is indeed one of the few venomous lizards on the planet. It wasn't until 2009 that the decades-long myth of how Komodo dragons kill was finally replaced with the truth, thanks in great part to Fry's research.

Unlike a snake, which injects venom into a victim through its sharp fangs, a Komodo dragon's venom seeps into large wounds it makes on whatever unlucky animal it attacks. The animal may escape the grip of the dragon, but it won't escape the venom that will eventually bring it down. By then, the Komodo dragon will be not far behind, tracking down its fleeing victim with its keen sense of smell.

3. Komodo Dragons Can Take Down Enormous Prey

Only reports of myth and mystery existed until explorers set off to confirm the existence of this fearsome prehistoric beast.
Only reports of myth and mystery existed until explorers set off to confirm the existence of this fearsome prehistoric beast. Ethan Daniels/Shutterstock

Komodo dragons are massive animals. Measuring as much as 8.5 feet (2.5 meters) long and weighing as much as 200 pounds (90 kilograms), it's no surprise they can take down animals as large as wild boar, deer, and water buffalo.

To catch their prey, they use an ambush strategy. Matching well with the dirt surroundings of their island home, they lie in wait for an unsuspecting animal to pass by. They then sprint into action, landing a venomous bite before the victim can escape.

4. They Have Impressive Armor

Researchers at University of Texas at Austin examined the armor of a Komodo dragon — which is built of thousands of tiny bones under the skin — because they wanted to know: What would the world's largest lizard need protection from?

Jessica Maisano, a scientist in the UT Jackson School of Geosciences, led the research along with Christopher Bell, also of the UT Jackson School; Travis Laduc, an assistant professor in the UT College of Natural Sciences; and Diane Barber, the curator of cold-blooded animals at the Fort Worth Zoo. Together, they looked at several specimens with high-powered X-rays called computed tomography, as they reported in The Anatomical Record in 2019.

They found that Komodo dragons have bony deposits in their skins, known as osteoderms, of many different shapes, which is unusual, but also that a Komodo dragon isn't born with them. Just as tree rings reveal the approximate age of a tree, osteoderms reveal the Komodo dragon's growth.

They also found the answer to that nagging question: The only thing Komodo dragons need protection from is other Komodo dragons.

5. When It Comes to Metabolism, They Aren't Like Other Reptiles

Most reptiles lack much in the way of aerobic capacity, but Komodo dragons are the exception, thanks to a genetic adaptation that researchers discovered when they sequenced the animal's genome. The researchers' work, published in the journal Nature Ecology & Evolution, showed these creatures can achieve a metabolism that's more like that of a mammal, which is beneficial when it comes to hunting prey.

Scientists at Gladstone Institute of Cardiovascular Disease at the University of California, San Francisco, found changes involving mitochondria, which are the steam engines of the cell. Much like a digestive track, mitochondria take in nutrients and provide fuel for the cell. This is doubly important for muscle cells, which Komodo dragons have in spades — and which also explains what's behind the creatures' unlikely bursts of speed and endurance.

6. Komodo Dragons Can Eat 80% of Their Weight in One Sitting

Komodo dragons can eat so much at one sitting that they may go as long as a month before needing another meal
Komodo dragons can eat so much at one sitting that they may go as long as a month before needing another meal. Sergey Uryadnikov/Shutterstock

Not only are Komodo dragons big, but they have an appetite to match. When the massive lizards sit down to a meal, they are capable of swallowing down as much as 80% of their own body weight in food.

The huge feast and slow digestion mean that after eating, Komodo dragons will go lounge in the sun, with the heat helping to keep their digestion process working away. After the meal is digested, a Komodo dragon will regurgitate what is known as a gastric pellet. Similar to owl pellets, the gastric pellet contains horns, hair, teeth, and other bits of prey that can't be digested.

Because their metabolism is fairly slow and they can pound down so much in a single sitting, Komodo dragons can survive on as little as one meal a month.

7. Komodo Dragons Are Infamous for Grave Robbing

Komodo dragons don't always — or even often — hunt for their meals. Instead, they eat a lot of carrion. They can detect a carcass as far as six miles away.

Unfortunately for humans living among the dragons, that can mean they feast on the recently buried. This has caused people living on Komodo to switch from graves on sandy ground to clay ground, and add a pile of rocks on top of the grave for good measure.

8. Female Komodo Dragons Can Reproduce Without Sex

Komodo dragons lay clutches of eggs that hatch in April, when there are a large number of insects for the small hatchlings to feast on.
Komodo dragons lay clutches of eggs that hatch in April, when there are a large number of insects for the small hatchlings to feast on. Ethan Daniels/Shutterstock

These ancient beasts remind us not only of the prehistoric dinosaurs featured in the classic movie "Jurassic Park," but their reproductive behavior harkens back to something highlighted in the film as well.

In 2006, a group of researchers verified that female Komodo dragons can reproduce asexually through a process called parthenogenesis. When no males are present, females can still lay a viable clutch of eggs.

It was females at two zoos, kept in solo conditions, that provided the eggs for the researchers to analyze and confirm that Komodo dragons are capable of parthenogenesis — one from London's Chester Zoo and one from the London Zoo. Genetic analysis of some of the eggs from their clutches confirmed that no male contributed to fertilization; the females were both the mother and the father of their offspring.

While parthenogenesis occurs in some 70 species around the world, this was the first time it had been confirmed in Komodo dragons.

9. Komodo Dragons Are Known to Cannibalize Baby Dragons

It may be amazing that female Komodo dragons can reproduce with or without the presence of males. But something that isn't quite so inspiring is that those little offspring might just be an easy meal.

If other prey isn't available, or it just looks like a youngster would make a nice snack, an adult Komodo dragon isn't above snagging one for lunch. For this reason, young Komodo dragons will spend time up in trees, avoiding getting in the path of larger lizards. That's not the only behavior that helps keep them alive to adulthood.

According to the Smithsonian National Zoo, "Because large Komodos cannibalize young ones, the young often roll in fecal material, thereby assuming a scent that the large dragons are programmed to avoid. Young dragons also undergo rituals of appeasement, with the smaller lizards pacing around a feeding circle in a stately ritualized walk. Their tail is stuck straight out and they throw their body from side to side with exaggerated convulsions."

10. They're Surprisingly Speedy

Watching a Komodo dragon coming your way might be one of the world's most unnerving scenes.
Watching a Komodo dragon coming your way might be one of the world's most unnerving scenes. Kiwisoul/Shutterstock

They may look large and lumbering, but these lizards are all muscle and can move with explosive speed. In an all-out sprint, a Komodo dragon can run at an impressive 12 miles per hour (19 kph). The average human sprints at just 15 miles per hour (24 kph). So if you're caught by surprise by a charging Komodo dragon that was lying in wait for a meal, run like your life depends on it. Komodo dragons have been responsible for the death of four people in the last 41 years. Don't underestimate their speed just because of their bulk.

11. They're Also Surprisingly Playful

So we've talked a lot about the ferocity, speed, grave-robbing, and cannibalistic tendencies of these behemoth lizards, but we wouldn't want to leave you with an unbalanced impression. There's a softer side to them — sort of.

It turns out Komodo dragons also engage in play. Captive individuals have been observed playing with shovels, shoes, and even Frisbees. The way the individuals interacted with the objects was shown to be without aggression or food motivation, and can be considered play.

Just in case you wondered what it looks like to play tug-of-war with a Komodo dragon, check out the surprisingly cute video above. (No really, it's cute!)