The origins of flight are debated, but one thing is certain: it began as gliding. And, most likely, it began as gliding from tree to tree in the forest canopy. As of yet, there are only two ways to truly fly: have wings on the back (like insects), or wings on the forelimbs (like birds and bats). But nature is constantly innovating, finding new ways to get high. Today, we look at some gliding prototypes being developed in the laboratory of the rainforest canopy, and imagining what kind of flying animals they might become.
The Prototype: Flying Dragon
I love animals that sound like kung fu moves. The flying dragon of Southeast Asia has developed a different way to glide: it extends flaps of skin connected to special, movable ribs to create “wings” in its midsection; its obvious advantage is that, unlike birds or flying squirrels, its arms and legs are free, so it can read the SkyMall catalogue. It’s able to glide about 25 feet, even executing a nifty little loop-de-loop to slow its descent near landing.
The Future Model: The Butterfly Lizard
Okay, gliding lizards have existed for 144 million years. So if this design could turn into powered flight, it probably would have by now. But if you gave the lizard a keel, the breastbone in birds to which the flight muscles attach, the flying dragon could conceivably evolve into a fluttering lizard with brightly-colored wings, making short, powered jumps upwards into the canopy to catch slow-moving insects in its elongated forearms.
The Prototype: Flying Snake
These snakes extend their ribs slightly, and suck in their belly to make it concave — think of the curve of a Frisbee. They push off from a tree in the desired direction, then undulate to maintain balance and stability while they gently fall. Despite having no wings at all, flying snakes are superior gliders even to flying dragons and flying squirrels, achieving up to 100 meters of aerial distance and, in smaller species, even truly horizontal gliding.
The Future Model: The Heli-Snake
Flatten the body more, perhaps give the snake a “frill” of extended skin like the flying dragon’s, and it wouldn’t take much to create a true flying serpent. I can envision it gaining altitude by turning its rippling body into a helix or whirligig, then using that altitude to glide nearly horizontally between the tallest trees of the Amazon in search of birds’ nests and small mammals.
The Prototype: Flying Frog
Alfred Russell Wallace, AKA “The other Darwin,” was the first European to discover these frogs of Borneo, who use their webbed feet in the air the way other frogs do in water. The splayed toes on each foot create four miniature airfoils; not great for lift, but superb at maneuverability. The gliding is barely more than controlled falling, but when you live over a hundred feet in the trees, not going “splat” is a pretty strong evolutionary incentive.
The Future Model: The Bat Frog
Somebody already beat me to my conclusion here. But in my mind, those webbed hind limbs might also serve as wings. Yup, evolution is clearly headed towards four-winged bat frogs. And why not? Four-winged bird dinosaurs were hot, for a while.
The Prototype: Gliding Ant
This one is my favorite. A canopy ecologist in Panama, working a hundred feet in the trees, was in the habit of brushing ants off the limbs where he was working. Most ants, when you drop them, fall straight down. But the scientist noticed that certain types of ants could actually direct their fall, without the use of wings, glide back to the tree trunk and climb back to the place where they were brushed off. Their flattened, winglike heads and hind legs help orient their fall, while hooks on their feet catch the trunk as they smack it at a steep angle and high velocity. They’re sort of the Darth Vader of the ant world.
The Future Model: Kite Ants
Queen ants already have wings, for a while, so flying ants aren’t inconceivable. But what if the ants simply improved their gliding abilities; becoming flatter and wider to catch the wind, and turning their heads into little hang-gliders, so that the colony could become 100% arboreal, never needing to touch the ground? A colony of kite ants, when determined to move, could climb to the treetops and catch the wind, staying together by grabbing forelimbs to become a super-kite, or by releasing strong beacon pheremones to find each other upon landing. It’s a whole new way to ruin your picnic.