Sunday 15 November 2015

Flying Dragon

Image: Psumuseum
*GASP* It's a dragon! A mighty, fire-breathing dragon of yore with teeth like daggers and eyes like embers. Look at his fearsome claws, his lashing tail, his majestically curved neck. He's spreading his majestic wings like a scaly but also majestic banner of unearthly power. Watch him take to the air with majestic flaps of the aforementioned majestic wings. I've never seen a majestic flap before but it's oh so very majestic.

He's... he's coming this way. Run!

Image: Bernard DUPONT
Five-banded Flying Lizard (Draco quinquefasciatus)

He looks different close up.

Image: Bernard DUPONT
Draco quinquefasciatus
Flying Dragons are more than 40 species belonging to the genus Draco, found in south and southeast Asia from southern India to Indonesia. They're also known as Flying Lizards, which is more boring but also more accurate since they are indeed lizards. If you wanted to be even more accurate you would call them Gliding Lizards since they don't actually fly.

Regardless, Draco is Latin for dragon and Flying Dragons are the cutest, little dragons ever. So there.

Image: Carmelo López Abad
Draco palawanensis
The very biggest ones may reach a little more than 30 cm (a foot) long, though a good two thirds of that length is made up of a long, thin tail. Most species are more or less half that length and they're all spindly little creatures who spend their time clambering about the trees, feasting mostly on ants and termites.

They have fantastic camouflage which lets them easily disappear among the tree trunks and branches. Flying, or gliding, isn't quite so good for camouflage but it's great for when they want to check if the rumours are true and the grass really is greener on the other side. Or the leaves greener on the other tree. Or the termites plumper.

Video: NatGeoWild

Flying Dragons are amazingly accomplished gliders. One of the best, in fact. They think nothing of jumping nose-down from a tree and gliding a good 10 metres (30 feet) to the next one.

As you might imagine, they have all sorts of adaptations to achieve gliding prowess, the most obvious of which are their wings. Now, there are quite a few different kinds of wing out there. The bat's mega-hand. The pterosaur's mega-finger. The bird's mangle-arm. Not to mention the insect's elegant solution of simply growing a pair of wings and keeping all their limbs intact.

Image: Siler, Cameron
Philippine Flying Dragon (Draco spilopterus)
But Flying Dragons are gliders, not actual fliers. Many gliders make do with a big flap of skin stretched from wrist to ankle to form a kind of sky-diving suit which can be deployed by simply spreading the arms and legs out. Flying Dragons have something like that, except it isn't attached to their wrist or ankle. This is a bit of a problem when the whole thing is made up predominantly of skin. So they've had to come up with a solution.

It's novel, but at the same time rather old-fashioned...

Image: President and Fellows of Harvard College
Big long ribs!
Bones. Their wings are supported by good, old, reliable bones. But they're not arm or leg bones like in a bat or a bird. They're RIB BONES! They have extra-long ribs that extend through their thin, membranous wings to support them in flight. I mean glide. Support them in glide. They also have joints where they meet the spine so the Flying Lizard can fold his wings against the body when they're not in use.

Rib wings! Jeez. Insects must be facepalming so hard. They're like, "what's up with you people? Just GROW WINGS, innit?"

Image: Patrick Randall
Flying Dragons have more than just the wings, though. On each side of their neck are little flaps which they extend in flight- I mean glide - for more lift and balance. They look a bit like the tail fin on an aeroplane, but on the front. Even their long hind legs bear modified scales to help with lift.

A Flying Dragon in flight- GLIDE - is quite a sight. Like a flamboyant Batman trying out a more colourful costume to see if it'll raise his mood a little. While Flying Dragons are mostly bark-coloured or leafy green for camouflage, the underside of their wings is usually bright and eye-catching. The reason for this is to... catch the eye, gain attention, but only from other Flying Dragons.

Video: Rick

Lots of those nimble, sprightly lizards you see leaping about the tree branches have what's called a dewlap. It's a flap of skin on the underside of the neck which the lizard can extend or retract at will. It's usually brightly coloured for communicating to others with a flash of red or bright yellow.

Flying Dragons have a dewlap. And then, just to reinforce the message, they have those brightly coloured wing undersides which can be unfurled to really scream "oi, I'm here. Me. Here. You see?"

Image: A.S.Kono
Sulawesi Lined Gliding Lizard (Draco spilonotus)
Males often have to use this kind of display against other males. They're territorial, each one trying to claim ownership of two or three trees. If an interloper gets too close, a male's got to do what a male's got do: flutter his pretty wings. That'll show 'em.

They save their most vigorous displays for the ladies, of course. There'll be a few females milling around in his territory and he woos them by spreading his wings and dewlap to the utmost, bobbing up and down and perhaps walking around her in circles.

Image: Seshadri.K.S
Common Gliding Lizard (Draco sumatranus)
If the fella meets her most stringent standards, they'll get down to some hot, fire-breathing dragon love. No doubt it's extremely majestic.

With that done, the female has a mission on her hands. She has eggs to lay but she doesn't build a nest or even retire to a tree hollow. Nope. She crawls down a tree and descends to the dark underworld of the forest floor. There she uses her snout to dig a hole in the soil for her eggs. Some Flying Dragons will hang around guarding the nest for a day before leaving to let the eggs fend for themselves.

They hatch in a few weeks and tiny dragons emerge into the forest and gaze up at the trees that tower over them and will soon become their home. It's a long climb for a tiny dragon. If only they could actually fly with majestic flaps!


TexWisGirl said...

so very cool! go, little dragons, go!

Joseph JG said...

Haha! I wonder if they say "vroooom" or "weeeeeee"?

Lear's Fool said...

And the flies are like 'We even ditched half of our wings for little gyroscopes, and we STILL have wings and limbs'

On the positive side, we exist because flying tigers don't!

BK said...

Unfortunately for these lizards, their primary predator is another flying squamate; the flying snake (Chrysopelea sp.)

Joseph JG said...

@Lear's Fool: Haha! Thank goodness for the abundant lack of manticores!

@BK Jeong: Oh dear, poor guys just can't get a break!

Porakiya said...

these little guys are one of my favorite lizards!

Also, at least they're more dragon-y than bearded dragons and komodo dragons ;)

Joseph JG said...

Hahaha! I hadn't thought of that. They're definitely the most legitimate dragons around today.