The Ark Files - Springing into Spring

Hop, spring, jump ... fleas do it and so do whales. Leaping is common to all the animal groups

Spring loaded

Fleas and grasshoppers with their very long legs are the best known insect leapers but there is a tiny leaf litter creature called a springtail which can out-do them both. Springtails have a forked tail-like tube which they keep folded beneath them but when released this "spring" thrusts forward and backward, enabling the springtail to jump considerable distances through the leaf litter.

Jumping spiders are brightly coloured and have superb eyesight. They are hunters who stalk and pounce on their prey. Just before attacking, the spider attaches a dragline and flattens its body against the ground. Jumping spiders leap by sudden extension of the legs caused by a very rapid increase in their blood pressure.

Catch me.. if you can

Frogs are amazing leapers. The biggest frog of all, the Goliath Frog from West Africa, is able to jump three metres. A frog doesn't hop simply to get from place to place. Hopping is also a very effective method of escape - so explosive, so surprising that catching a frog can be very tricky, whether you are a human or a hungry bird or reptile.

Leaping lizards

In the dense jungles of Borneo there lives a little lizard that can shoot itself from tree vines to branches and back again with such incredible speed that it seems like a miniature rocket.

Hop two it.. or four it?

Kangaroos have made the hop into an art form. Their hind legs are enormously powerful and the long tail is held out stiffly behind to act as a counterbalance so the roo, in bursts, can reach speeds of up to 60km/h and clear fences nearly 3m high. Kangaroos graze on the open plains, so speed and agility are necessary if you are going to expose yourself to attack by hunting predators. But why hop? Why not run on all fours? One reason may be that when moving at high speed over rough and rocky ground it is easier and safer to carry large babies in a pouch in an upright position. But the main reason is that hopping is amazingly energy-efficient.

The Spinifex Hopping Mouse can hop on two or four legs. This small, nocturnal, long-tailed rodent has extremely long and narrow hind feet. Normally it moves awkwardly on all fours or makes short hops, but if startled it performs feats of amazing dexterity, springing gracefully and constantly changing direction as it leaps about on two or four legs.

Primate ping-pong

The Indri is the most magnificent of all tree jumpers. It is the largest of all living lemurs with a body nearly a metre long. It has extraordinarily long legs with feet like huge calipers with which it can grasp even thick tree trunks. Poised on a tree, the Indri launches itself with an explosive straightening of the hind legs and travels upright through the air in soaring bounds over and over again, so that it seems to bounce its way from trunk to trunk through the forest.

Having a whale of a time

But perhaps the most awesome spring of all (given their immense size) is the breach of Hawaiian Humpback Whales. In this spectacular display the whale builds up speed underwater and with the help of its powerful flukes, generates enough force to propel its body, all 50 tonnes of it, above the ocean's surface. It twists in mid-air, displaying its ridged belly, before plunging back into the water with a thunderous crash, and creating a gigantic surge.

There are a number of theories about this breaching behaviour of whales. It is thought that it may be a communication signal to other whales; a courtship ritual; a display of prowess; a sign of agitation or competition; a way to rid the whale of itchy barnacles; or perhaps the whale is just having fun!