Kangaroo Hopping & Their Extra Leg Macropod Locomotion by Hopping
The key characteristic of macropods, such as the kangaroo, are their prominent hind legs and their use of hopping as a means of moving from one place to another (i.e. locomotion). At slow speeds they also use their tails in the most unusual way..
Note: This article refers to how a kangaroo moves but the principles apply to all macropods, except the Musky rat-kangaroo which has long hind legs but does not hop.
As with all macropods, kangaroos have large strong hind legs and large feet specially designed for hopping. It has perfected this mode of locomotion to make it one of the fastest and most efficient methods of traveling over long distances. It is the only large animal that uses hopping as a method of locomotion. The kangaroo's legs are specially designed for this purpose.
Using this method of locomotion a Red Kangaroo, for example, usually hops at a speed of about 20-25 km/h. It can also speed away at over 70km/h and leap over 3 meter obstacles when required. These kangaroos have been recorded travelling up to 20 kilometres at speeds of 40km/h without a stopping for a rest. A single hop from a kangaroo can cover up to 8 meters! A human stride is only about 1 meter. Even an elephant can only manage about 2.5 meters.
How Does a Kangaroo Hop? The Mechanics of Hopping
When a kangaroo hops its legs compress, bringing its toes towards its body. This functions like a spring being compressed. Then its toes move away from its body and its bounces up like a spring being released. The concept is similar to how a Pogo Stick works.
The actual mechanics of how this works is not what it seems. While it hops around like on a pogo stick it actually gets its bounce from its Achilles tendons in the back of its legs. These tendons and associated ligaments act like giant stretching and shrinking rubber bands. When its legs compress, its tendons get stretched. Then the energy stored in the stretched tendon – referred to as elastic potential energy – together with contracting muscles start pulling the bottom part of the leg downwards giving the animal a springing bounce back into the air. In this way a Kangaroo uses very little energy to move itself about. By using gravity and its weight to work its springy tendons a kangaroo is estimated to us 40% less energy than a comparable four-legged animal..
Advantages of Hopping Why Does the Kangaroo Hop?
Kangaroo Hopping is Super Efficient
Scientist suggest that the kangaroo has the most efficient method of locomotion of any ground animal in the world. At speeds above 6km/h, it actually uses less and less energy as its speed increases. At speeds above 18kph, a hoping kangaroo uses less energy than any other animal of equivalent weight. If a foxhound were to chase a kangaroo, it would consume twice as much energy and would tire out in less than 2 kilometres. The kangaroo, on the other hand, could go another 20 kilometres and still seems as fresh as when it started.
Kangaroo Hopping is Silent
Kangaroos move extremely quietly compared to other animals. You would hardly notice a mob of kangaroos whooshing silently past you at top speed. An equivalent number or deer, which are similar in body sizes, would create quite a loud racket. The reason for this is the kangaroo's soft padded feet, relatively small footprint and the fact the only two feet touch the ground.
Kangaroos increase their speed by increasing the length of their hops – not the frequency of hops. When its wants to go slow it takes small hops. When it wants to go fast it takes large hops. All other animals increase the speed of each step, with only a very small increase in their stride.
How Fast Can a Kangaroo Go?
The fastest kangaroo is the red kangaroo. It has been recorded at speeds of up to 70kph. At this speed each of its "strides" is as much as 8 meters apart. (The record is an astonishing 13 meters). Because hopping is super-efficient, it can also maintain this speed for a long period of time without exhausting itself.
Because the kangaroo uses bi-pedal (two legs like humans) locomotion it can easily pivot on one foot and rapidly change direction. It is claimed that it can make a 180 degree turn in a single hop. Four-legged animals with their relatively long bodies cannot turn as rapidly.
A Kangaroo Can't Move Backwards
A Kangaroo can make very limited hops backwards when fighting. It cannot however actually do so as a means of locomotion.
A Kangaroo Can't Walk
A Kangaroo cannot walk forward or backwards by moving its legs independently. The kangaroo can, however actually move its legs independently it just can't do so for walking.
A Kangaroo Can't Move its Legs Independently
A kangaroo can move its legs independently when required but while hopping kangaroos usually move both hind legs together. The independent movement of its legs occur when the animal is turning while it is hopping, when it places one leg slightly in front of the other to execute a turn. When it uses its feet in 'foot thumping' to warn other kangaroos of danger and when swimming.
How High Can a Kangaroo Jump?
Did You Know
The largest non-marsupial animal to hop is the rabbit, which hops using all four legs.
The red kangaroo hold the high jump record too. It can jump as high as three meters.
Hopping Doesn't Work Well at Slow Speeds
At low speeds, however, a kangaroo is far less agile. Its super-efficient hopping legs let it down. (See next section to learn how a kangaroo moves at slow speeds).
Despite the kangaroo's reputation for gracefully hopping through the landscape, it actually spends more time moving at more leisurely pace of below 6 kilometres an hour as it feeds and socialises with other kangaroos. At this speed its movements are ungainly indeed. While highly efficient at higher speeds, a kangaroo's hind legs are cumbersome and almost useless at lower speeds. The kangaroo has adapted to this shortcoming by developing a fifth leg! Where is it, your wonder? It's the kangaroo's tail.
A kangaroo moves at low speeds by leaning forward on to its short front limbs, hoisting itself up with its tail and then shifting its hind legs forward. This method of movement is called 'pentapedal' (four limbs + tail) locomotion. Only the kangaroo does this. Recent research has shown that the kangaroo's tail with its 20 vertebrae acts like a fifth limb fulfilling the role of a normal leg. In this role it is capable of generating more forward force than all of the kangaroo's other limbs combined.
Our Other Fantastic Pages
Cute animal with soft fur and large nose. It carries its baby in a pouch. It sleeps a lot.View More
Blue Tongued Lizard
This lizard with short legs scares off predators by flashing its blue tongues.
Smallest kangaroo and only one that doesn't hop. Has very unusual characteristics
A non-aggressive venomous snake responsible for 16% of snake bites each year.
A huge rainforest bird with a deadly karate kick. It is endangered.View More
The world's largest and deadliest reptile. Growing up to 6m. Does attack humans.
Large animals that carry their babies in a pouch and hop at speeds of 70kph.
Australia has some of the most deadly and dangerous animals in the world.View More
Has a beak like a duck, a tail like a beaver, webbed feet like an otter & it lays eggs!View More
A large, deadly and aggressive spider with large menacing fangs.
A boisterous carnivorous marsupial with a shriek that sounds like a devil.View More
A bum-breathing turtle? Yes, that's right. It is critically endangered.
Marine mammals that ancient sailors thought were mermaids.View More
An odd little animals that lay eggs, but feeds their babies milk like a mammalView More
The 2nd tallest and the 2nd fastest bird in the world. A very curious bird.
Animals brought to Australia by humans. Many have become invasive and pests.