Wallace’s flying frog

wallaces-flying-frog

Odd Creatures is a recurring column about the world’s weirdest species written by award-winning science writer and author Bec Crew, and illustrated by the super-talented Aiyana Udesen

Why hop when you can fly? Meet Wallace’s flying frog (Rhacophorus nigropalmatus), a large, pretty species found in tropical jungles of Malaysia, Borneo and western Indonesia.

Just a bit smaller than the length of an iPhone, the species sports a bright, shiny green colouring with a yellow underbelly and black webbing between its yellow fingers and toes. It might be called a flying frog, but technically what it does is glide. Flying needs to be powered by something like regular wing movements or a motor, whereas gliding is more like… falling with style. Just as if it were parachuting, a gliding animal will make a slow descent to where it needs to be at an angle of no more than 45 degrees relative to the ground below.

Wallace’s flying frog is so good at this, it can glide as far forward as the distance it’s falling. This means that if one is launching itself from a height of 15 metres (49 feet), it’s capable of gliding at least 15 metres away from that spot, aided by some weird, aerodynamic skin flaps on its sides, and its enormous and extensively webbed feet and hands. These things are literally bigger than its head.

The thin black membrane that forms the webbing on a Wallace’s flying frog’s hands and feet stays folded up when the frog is at rest, and stretches out like a parachute when it launches itself into the air. When the frog is ready to land, its enlarged toe pads help it to grip instantly onto the surface of a tree, or will cushion its landing once it reaches the jungle floor.

Wallace’s flying frog was first discovered in 1855 and named by British naturalist, Alfred Russel Wallace. At the time, it was like nothing anyone had ever seen before. In fact, the existence of a frog that had grown beyond leaping and into something far more effective helped Charles Darwin form the beginnings of his theory of evolution by natural selection. Poor old Wallace had been in the process of formulating his own very similar theory, but threw the towel in once Darwin published On the Origin of Species in 1859.

Imagine being scooped by Charles freaking Darwin.

Several lizards that live in lofty jungle environments have also evolved gliding mechanisms to help them avoid and pursue their predators and prey. They’re yet to form winged feet like a Wallace’s flying frog, but a number of lizard species use skin flaps to help them glide. The flying dragon lizard (Draco volans) from the jungles of Southeast Asia and southern India has the most impressive skin flaps of all:

flying-lizard

Allowing it to glide more than 8 metres in the air, the flying dragon lizard’s sunset-coloured skin flaps are supported by five super-long and flexible rib bones on both sides of its body. These bones extend out from its sides to open up the skin flaps so they look like actual little dragon’s wings. Its long, slender tail works just like a rudder.

Oh and guess what? Frogs can glide, lizards can glide, and yep, so can snakes. And just this year, scientists figured out how they do it. Look at them go!

—Bec Crew / @BecCrew

2 Comments, Comment or Ping

  1. Great to see something different.. Keep it up

  2. Kim Diehl

    Great story! Love the Wallace scooped by Darwin part. Awesome illustration, too! Keep ’em coming!

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