Draco Lizards and Flying Dragons: Strange Reptiles
Strange and Interesting Reptiles
Draco lizards are strange and interesting reptiles that have folds of skin on each side of their bodies. When the skin folds are extended they look like wings. These "wings" enable the lizards to glide for long distances in their forest habitat.
Draco lizards are also known as flying or gliding lizards or, in the case of some species, as flying dragons. The scales covering a Draco lizard's body and the fact that it seems to have wings remind some people of a dragon. In fact, draco is the Latin word for dragon.
There are over forty species of Draco lizards, all of them native to Southeast Asia. They are classified in the family Agamidae. Members of this family are often referred to as agamids or agamid lizards.
In this article, the term "Draco lizards" refers to all animals in the genus Dracus. The term "flying dragon" is used for Draco volans. Many of the facts about this animal apply to its relatives as well.
A Draco Lizard Glides to Escape From a Snake
Physical Appearance of the Flying Dragon
The scientific name of the animal known as the flying dragon (or sometimes the common flying dragon) is Draco volans. Flying dragons are tiny reptiles, unlike their mythical counterparts. They have łong and slender bodies and reach a length of about twenty centimetres or eight inches. The lizards have a very long tail compared to the length of the rest of their body.
Like many Draco lizards, flying dragons have a mottled appearance and are generally a mixture of brown, grey, black, and green in colour. Their colours help to camouflage them against the trunks of the rainforest trees.
The wings are coloured and patterned differently from the body. The scientific name for the wings is "patagia" (or patagium when one wing is being discussed). The upper surface of a male's patagia is orange-red in colour and has black blotches, as shown in the photo above. The lizard in the photo is Draco sumatranus, or the common flying lizard. It was once considered to be a subspecies of the flying dragon. The upper surface of a female's patagia is yellow with black blotches, although there may be some orange present as well.
The lizards have a loose flap of skin called a dewlap or gular flap hanging below their neck. Like the wings, the dewlap can be extended and is a different colour from the body. The male lizard has a yellow dewlap while the female has a smaller, blue-grey one.
A Flying Snake Hunts a Draco Lizard
Wings and Gliding Ability
A flying dragon's wings extend from just behind the front legs to just in front of the back legs. The last five to seven of the animal’s ribs are elongated and extend into the wings. Muscles attached to the ribs cause the ribs to move and the wings to unfurl like an opening fan when the animal wants to glide. Research suggests that the "hands" of the lizard's forelimbs grab hold of the wings to help them unfurl.
The lizard has a smaller wing, or lappet, on each side of its neck. When the lappets are extended to the side, they act as mini-wings that help the animal to glide.
Some reports state that flying dragons can glide as far as sixty metres (just under two hundred feet), or even further, and that they lose one foot in height for every five feet travelled through the air. Most flights seem to be around thirty feet, however. The lizards have better control of their motion than other reptiles that take to the air, such as flying geckos and flying snakes (which are also gliders, despite their names). Flying dragons can move their patagia as they glide. They can also move their tail, which acts like a rudder for steering. The animals have a flattened appearance while they are gliding.
The Southern Flying Lizard or Draco dussumieri
Life in the Trees
Flying dragons are active during the day. They glide from one tree to another, or sometimes from one branch to another in the same tree, in order to find food or a mate or to escape from predators.
Males also glide to chase away other males. A male patrols a territory of a few trees, gliding around the trees to protect them from invading lizards. When the males land they often flash their dewlaps to advertise their territory, which unfortunately also makes their presence more visible to predators. They do have one advantage over many of their predators, though—the ability to take off into the air and control their direction with precision.
When they’re not gliding, the animals often travel rapidly up and down tree trunks and along branches. They may also stay motionless for a while, becoming very hard to see as they blend in with their background.
Most of a flying dragon's diet consists of ants, but it also catches termites and other insects. The lizard often feeds as it ascends a tree trunk. A male very rarely—if ever—comes to the ground. A female comes to the ground to lay her eggs, however.
It's thought that the lizard's chief predators are arboreal (tree-living) snakes, large birds, and monitor lizards. Despite the presence of their predators, though, most flying dragons are very successful in their habitat.
Small lizards tend to live lower in the tree canopy than larger ones. When the heavier animals take off from a tree they need to develop speed before they extend their wings to glide. Starting their journey from a higher point helps them to do this.
There is still much to be learned about the lives of flying dragons in the wild, including information about their reproduction. Researchers know that the animal has an interesting mating display. During courtship, the male displays his dewlap and his wings to attract females and also bobs his body up and down.
After mating, the female digs a hole in the ground with her snout. She deposits up to five eggs in the hole, which she covers with soil. She guards the eggs for about a day and then leaves them on their own. The estimates for the length of time between egg laying and egg hatching vary widely. The time likely depends on environmental factors.
The Mindanao Flying Dragon
The Mindanao flying dragon lives in the Philippines and has the scientific name Draco mindanensis. It's been found on the island of Mindanao and on neighbouring islands, but none of the populations seem to be dense.
The lizard's body is pale grey-brown in colour. The upper surface of the body has both large and small white spots. The upper surface of the male's patagia is red while the female's is dark grey. The dewlap of the male is an attractive orange colour. The female's is duller and has a yellow tip.
Like other gliding lizards, the Mindanao flying dragon lives in the forest, eats insects, and is active during the day. The lizard is larger than many of its relatives, however, and can glide further and faster.
Some people think that Draco lizards are poisonous, but researchers say that this isn't the case. The animals are actually harmless to humans.
Population Status and Conservation
The IUCN (International Union for Conservation of Nature) classifies animal populations according to their nearness to extinction. Unfortunately, the Mindanao flying dragon is classified in the "Vulnerable" category. The lizard is threatened by deforestation. Efforts are being made to protect the lizard's rainforest habitat, which will hopefully allow its population to grow or to at least stabilize. The status of the common flying dragon population hasn't been assessed by the IUCN.
Draco lizards are unusual and fascinating little creatures. They are well adapted to their forest habitat and are fun to observe. The flight of the lizards is a beautiful and often impressive sight. Hopefully we will be able to see this flight for a long time to come.
Facts about the common flying dragon from National Geographic
Forelimbs and flight in Draco lizards from New Scientist
Information about the southern flying lizard from the IUCN Red List
Mindanao flying dragon report from the IUCN
The biology of gliding in flying lizards from Oxford University Press
© 2011 Linda Crampton