Southeast Asia is a strange place. What is left of the rapidly vanishing forests is home to some animals with remarkable adaptations. The most remarkable of these in terms of travel is the ability to glide or fly between trees or leap out of the water and take to the air to escape predators. This must have been very important for many animals, so it is quite common for the forest and aquatic inhabitants to have some sort of adaptation to deal with this. Please welcome the animals that have taken to the air. We all know about flying birds and insects, as well as mammals like bats but every higher vertebrate group is represented by something that can fly, or at least glide. This includes:
- Colugo or flying lemur
- Giant flying squirrels
- Gliding dragons (genus Draco)
- Gliding snakes (Genus Chrysopelia)
- Gliding geckoes
Maybe not in the forest, but out at sea and around the coasts we can add flying fish (Exocoetidae) to the list to complete it.
It was the flying frogs that I wanted to have a look at. These are remarkable animals and are convergent with remarkably similar species in South America. They look much like what most people would consider “normal” for a tree frog, you know the type- green with sticky pads on the fingers and toes. But it gets better, the webbing in flying frogs’ fingers and toes has been greatly expanded, giving rise to the generic name for the Asian species Rhacophorus which literally means “Rag bearer” as revealed to the outside world by adventurer and hardcore scientist Alfred Russell Wallace. This is used to at least reduce the terminal velocity (maximum falling speed) of the frogs as they leap away from danger or head to the forest floor to breed (the only time they leave the tree tops). This is the case with the Harlequin flying frog (Rhacophorus pardalis) which is not much of a glider, usually gliding vertically. The master of this domain is the Wallace’s flying frog Rhacophorus nigropalmatus. This frog can glide at a 45 degree angle due to its larger surface area due to massively over sized fingers and toes- with the webbing to match. You can read about how Phil Lewis and I got these pictures and found these frogs by clicking on the text.