The red-legged running frog

Frogs are generally recognized as exceptional jumpers and, relative to their size, the best jumpers of all vertebrates.[78] The Australian rocket frog, Litoria nasuta, can leap over 2 metres (6 ft 7 in), a distance that is more than fifty times its body length of 5.5 centimetres (2.2 in).[79] There are tremendous differences between species in jumping capability. Within a species, jump distance increases with increasing size, but relative jumping distance (body-lengths jumped) decreases. The Indian skipper frog (Euphlyctis cyanophlyctis) has the ability to leap out of the water from a position floating on the surface.[80] The tiny northern cricket frog (Acris crepitans) can "skitter" across the surface of a pond with a series of short rapid jumps.[81]

Slow motion photography shows that the muscles have passive flexibility. They are first stretched while the frog is still in the crouched position, then they are contracted before being stretched again to launch the frog into the air. The forelegs are folded against the chest and the hind legs remain in the extended, streamlined position for the duration of the jump.[37] In some extremely capable jumpers, such as the Cuban tree frog (Osteopilus septentrionalis) and the northern leopard frog (Rana pipiens), the peak power exerted during a jump can exceed that which the muscle is theoretically capable of producing. When the muscles contract, the energy is first transferred into the stretched tendon which is wrapped around the ankle bone. Then the muscles stretch again at the same time as the tendon releases its energy like a catapult to produce a powerful acceleration beyond the limits of muscle-powered acceleration.[82] A similar mechanism has been documented in locusts and grasshoppers.[83]

Walking and running

Frogs in the families Bufonidae, Rhinophrynidae and Microhylidae have short back legs and tend to walk rather than jump.[84] When they try to move rapidly, they speed up the rate of movement of their limbs or resort to an ungainly hopping gait. The western narrow-mouthed toad (Gastrophryne olivacea) has been described as having a gait that is "a combination of running and short hops that are usually only an inch or two in length".[85] In an experiment, Fowler's toad (Bufo fowleri) was placed on a treadmill which was turned at varying speeds. By measuring the toad's uptake of oxygen it was found that hopping was an inefficient use of resources during sustained locomotion but was a useful strategy during short bursts of high-intensity activity.[86]

The red-legged running frog (Kassina maculata) has short, slim hind limbs unsuited to jumping. It can move fast by using a running gait in which the two hind legs are used alternately. Slow motion photography shows that, unlike a horse that can trot or gallop, the frog's gait remained similar at slow, medium and fast speeds.[87] This species can also climb trees, and shrubs and does so at night to catch insects.[88] The Indian skipper frog (Euphlyctis cyanophlyctis) has broad feet and can run across the surface of the water for several metres (yards)