Head to head
Flying Frog vs Tree Frog
A flying frog is a kind of tree frog, just not the same family as the tree frogs of the Americas and Europe. And within that Old World family, only some species actually glide.
| Flying Frog | Tree Frog | |
|---|---|---|
| Relationship | Gliding members of the Old World tree frogs | A body plan shared by two families |
| Family | Rhacophoridae | Hylidae (true tree frogs) or Rhacophoridae |
| Webbing | Huge, full to the toe tips | Reduced or partial |
| Skin flaps on limbs | Present, adding surface area | Absent or minimal |
| Can control a descent | Yes; glides, banks, and steers | No; hops and falls |
| Where | South and Southeast Asia | Worldwide (Hylidae); Old World (Rhacophoridae) |
| Toe pads | Yes | Yes |
| Also in the family | Foam-nest frogs and moss frogs | Varies by family |
Flying Frog vs Tree Frog: common questions
Is a flying frog a tree frog?
Yes, in the broad sense. Flying frogs are members of the family Rhacophoridae, the Old World tree frogs or shrub frogs, which is the African and Asian equivalent of the American and European tree-frog family Hylidae. Both families are climbing, mostly night-active frogs with expanded sticky discs on their fingers and toes, and they evolved that lifestyle separately. So a flying frog is a tree frog by ecology and by body plan, just not a member of the same family as the tree frogs most Westerners know. Within the Rhacophoridae, only a minority of species are true gliders; the rest are ordinary climbing frogs.
Can a flying frog really fly?
No frog flies under power, but the gliding species genuinely control their descent rather than just falling. When a flying frog leaps from a branch, it spreads all four feet wide, and the large webs, the skin flaps on its limbs, and its flattened body act together as parachutes and wings. This slows the fall and, more importantly, converts part of the drop into forward travel and lets the frog bank and steer toward a target. A well-developed glider such as Wallace's flying frog can cover 15 metres or more from a modest height and land upright on a trunk or leaf, sticking the landing with its toe pads. An ordinary tree frog, lacking the webbing and flaps, cannot do any of this.
Why did gliding evolve in some tree frogs but not others?
Gliding is favoured where the payoff for moving between trees without descending to the ground is high, chiefly in tall, structurally complex rainforest where the forest floor is dangerous and widely spaced trees make ordinary jumping inefficient. In those conditions, any frog with slightly larger webs that let it travel a little further and land a little more safely gains an advantage, and selection enlarges the webs over generations. The same pressures have produced gliding independently in lizards, snakes, geckos, squirrels, and other mammals in Southeast Asian rainforest, which is why that region has so many gliding animals. Tree frogs in more open or temperate habitats, where trees are closer together or the ground is safer, gained no such advantage and kept modest webbing.