David Attenborough with red-eyed tree frog. © Anna Place/BBC
1. Frog or mole?
Surely the oddest of all frogs, Myobatrachus gouldii is the amphibian equivalent of a mole. Restricted to the arid south-west corner of Australia, it uses its powerful forelimbs to burrow through sandy soil in search of termites. Heavy rains bring it to the surface to mate, after which it vanishes again. As with most frogs of arid areas, there is no aquatic stage. The female lays large eggs in a chamber 1m underground, which develop directly into froglets.
2. Little but loud
Croaking is a quintessential frog trait, something they do to defend territories and attract mates. But the size of the frog has little bearing on the volume of its croak. For example, some species of coquí (pronounced ‘kokee’), which are rather small tree frogs, manage to create an ear-piercing din. The common coquí from Puerto Rico is just 3–5cm long, but its calls have been measured at 100 decibels at a distance of 1m – equivalent to a chainsaw.
3. Long jumpers
A frog’s skeleton has a number of modifications to make it a superb jumper. It is the muscles that actually power the leap, but these alone cannot explain a frog’s jumping abilities. Recent research has shown that frogs have amazingly stretchy tendons, which act like a catapult or bow to explosively release their stored energy. The arrangement of bones, muscles and tendons enables frogs to make prodigious leaps. Vaulting 1.8m, almost 62 times its own body length, the southern cricket frog from the south-eastern USA currently holds the frog jumping record.
4. Small but perfectly formed
At a mere 7.7mm long, Paedophryne amauensis is the smallest vertebrate on Earth. Discovered in 2009 after a painstaking search of forests in Papua New Guinea, the micro-amphibian lives its entire life on land and does not have a tadpole stage. It inhabits the moist leaf litter of the forest floor, hunting tiny invertebrates.
5. Eat with your eyes
For their size, frogs tackle relatively large prey: the horned, or Pac-Man, frog can eat a mouse. They lack teeth in the lower jaw and cannot chew, so to make swallowing easier they retract their eyes into the roof of their mouth to help force meals down.
To find out more about these amazing little amphibians, don’t miss the Natural World film Attenborough’s Fabulous Frogs, Thursday 28 August, 9pm, BBC Two.