Way back in 1758 Carl Linnaeus described a type of lizard that had strange flaps of skin on its sides that looked almost like wings. He named the genus Draco, which is from the Latin word for dragons... you know, those giant, mythical flying reptiles. Back then, scientists did not know if the wing-like flaps of skin were actually for flying. In fact, this possibility was debated all the way into the mid 1950s. Many scientists thought the flaps were used only for threat displays or mating displays. Finally, in the 1950s, scientists actually observed the lizards gliding from tree to tree on these flaps of skin.
What the heck is a Flying Dragon?
Normally I share a YouTube video closer to the end of the Awesome Animal feature, but in this case I think you need to see the video first, in order to fully appreciate the awesomeness of these lizards before I go into more detail.
Check out this must-see video from the BBC.
See what I mean? Impressive lizards!
There are actually about forty species of Draco flying dragons, and they live in dense forests in Bornea, the Philippines, and across southeast Asia into southern India. They are fairly small lizards, averaging about 8 inches (20 cm) in length, including the tail, and they are all insectivores, gobbling up numerous insects per day.
Typically, they are drab in color, but their wing-like membranes, called patagia, can be brightly colored.
Amazing Facts about Flying Dragons
First, we need to talk about this whole flying thing. What the heck—a flying lizard? Not exactly. When it comes to animals, the word flying usually refers to the animal's ability to propel itself through the air under its own power for a sustained period of time. Birds, bats, and many insects can actually fly. Pterosaurs were real flying reptiles, and they could flap their wings for sustained flight, but they went extinct about 66 million years ago.
Draco flying dragons are not miniature pterosaurs, and they cannot fly. Instead, they are lizards, and they glide instead of fly (kind of like flying squirrels, which I featured in a recent email).
Don't let that fool you, though! Draco lizards are really good at gliding. They sail through the air with precision control, and people have observed them gliding as far as 200 feet (60 m) between trees. Look out your window at a tree that is 200 feet away. That gives you an idea of how impressive this feat is.
By the way... look at the lizard on the right (on the tree) in the photo above. That is what they look like when their wings are not spread out—pretty much like a normal lizard.
How exactly do Draco lizards glide? That impressive patagial membrane (wing) is supported by special, elongated rib bones, which the lizard can spread wide after it takes to the air, using certain muscles that other lizards usually use to control their breathing. The lizard leaps from a tree and spreads its ribs, which spreads the patagial membranes on both sides of its body. It then grabs the membranes with its forefeet to hold them out, then arches its back to force the wings into a concave shape, which enhances lift. The lizard controls its flight path by moving the wings up and down with its forelimbs.
Check out those elongated ribs!
Okay, that makes sense. Now, WHY do Draco lizards glide? Remember, lizards are gobbled up by numerous predators. Walking around on the ground to get from tree to tree is dangerous business. So, there is a huge advantage to being able to glide between trees.
Maybe a better question is, why don't all lizards glide? There are many different answers. Not all lizards are small enough to glide. Not all lizards live in densely-forested areas (no point in gliding in a desert or grassland, right?). And there are numerous other reasons why not all lizards can glide. The question is kind of like asking, if gliding is good for Draco lizards, why can't people glide too?
In the past there have been other lizard species (now extinct) that have independently evolved this same ability. For example, there was a family of gliding lizards called Kuehneosauridae that lived during the Triassic period (251 to 201 million years ago). Their fossils show a similar structure to today's Draco lizards (see artist depiction below).
Male flying dragons also use their "wings" as displays to impress females. This is probably why some of them have brightly-colored patagia. In addition to their patagia, the males also have dewlaps, colorful folds of skin beneath the chin that males can extend to further add to their impressiveness (see below).
The males establish territories and guard them fiercely to keep other males out. Of course, the females are always welcome, and they move from territory to territory, checking out the males to see which one they are most impressed with.
So, the Flying Dragon deserves a place in the C.A.H.O.F.
(Choice Animal Hall of Fame).
FUN FACT: The word choice originated as a noun in about 1300. It came from the earlier French word chois, and its original meaning was "action of selecting" or "power of choosing" (as in, "I have no choice—I must read Stan's new book"). In the late 1300s, the word was also used as a noun for "the person or thing chosen" (as in, "Stan's new book is going to be my next choice"). Sometime in the mid 1300s, people began using the word as an adjective to mean "worthy of being chosen; excellent; superior" (as in, "Stan's new book will be one of the choice novels of our generation").
So, choice is another way to say awesome!
Flying dragon gliding #1 - Psumuseum, CC BY-SA 3.0, via Wikimedia Commons
Flying dragon on tree with yellow patagia spread open - A.S.Kono, CC BY-SA 3.0, via Wikimedia Commons
Flying dragon landing on a tree - DepositPhotos
Flying dragon skeleton diagram - Wikimedia Commons
Prehistoric gliding lizard art - Nobu Tamura (http://spinops.blogspot.com), CC BY 3.0, via Wikimedia Commons
Draco volans displaying with dewlap - DepositPhotos
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