Kangaroo What is a Kangaroo?
Kangaroos are a large herbivorous hopping marsupial mammals found in Australia. They are members of the scientific animal group Macropodidae. Only the four largest animals in this group are referred to as kangaroos. These are the Red Kangaroo, Eastern Grey Kangaroo, Western Grey Kangaroo, and Antilopine Kangaroo.
Kangaroo - Description & Characteristics What Do Kangaroo's Looks Like?
Kangaroos have a triangular, upright posture supported by two disproportionately large hind legs, small forelimbs, and a large thick tail. The females of the species have pouches on their abdomen in which they carry their young. They can hop at speeds of up to 70 km/h.
Weight & Colour
Kangaroos have short fur which varies in colour from orange-brown to grey to dark brown. Males are larger than females. They can vary in size from the Red Kangaroo which can grow to 2.5 meters in height and weigh up to 90kilos, to the Antilopine Kangaroo which is about 1.3 meters tall and weighs about 43 kilos.
10 Kangaroo Facts
- The kangaroo, Australia's most famous animal, is a hopping marsupial macropod.
- The four largest macropods are called kangaroos.
- These include the Red, Eastern Grey, Western Grey, and Antilopine kangaroos.
- The kangaroo hops rapidly on its hind legs.
- But walks on its five legs! Yes, that's right. That's because it uses its tail as a leg too.
- A kangaroo can travel long distance at high speed and can jump up to three times its own height.
- The kangaroo female carries and nurses its babies in an outside pouch on its tummy.
- The male kangaroo has a two-pronged penis located behind its scrotum.
- The female has three vaginas and two uteruses.
- Kangaroos do environmentally-friendly low-methane farts.
Eyes & Ears
A kangaroo's eyes are located high on its skull and provide it with a 324° field of vision with a 25° overlap (humans have a 180° vision with 120° overlap). Its eyesight has a sensitivity comparable with that of rabbits, cattle or horses. They have large pointed ears that can swivel independently of each other through 180 degrees.
Teeth, Mouth and Sound (Vocalisation)
The kangaroo has large outward projecting front incisor teeth which it uses to slice through grass and leaves on which it feeds. Large molars at the back of its mouth chop and grinds its food. The kangaroo replaces its teeth throughout its life. New teeth grow and slowly move forward, replacing those in front which have been worn down or damaged. Four sets of replacement teeth are produced during the animal's lifetime, after which lost teeth are no longer replaced. If the animal hasn't died of old age by then, it will eventually die of starvation because it has no teeth left.
Kangaroos have very small almost non-existence vocal cords. For this reason, they have a very limited range of vocal sounds. A mother communicates with her offspring with clicking sounds. An alarmed kangaroo may hiss and growl. A kangaroo may display aggression by making a "ha" sound. A male kangaroo may also make a chuckling sound during courtship.
Arms, Paws & Claws
The kangaroo has short, small forelimbs. Its hands have five clawed fingers. These hands are used primarily for grasping and pulling down branches, fighting, and grooming. They are also used for pentapedaling (crawl-walking). The kangaroo has an unusual way of keeping cool. It licks its forelimbs covering them with saliva, and as the saliva evaporates, it helps to cool its body.
Only female kangaroos have pouches. Male kangaroos do not have pouches. Like all marsupial mammals, the female kangaroo rears its offspring in its pouch and feeds it milk. The pouch is located on its abdomen. A young kangaroo, which is born very immature, crawls up from the mother's birth canal to the pouch where it attaches itself to a nipple and remains for over four months before it ventures out. Even adolescent kangaroos will hop back into their mother's pouch when frightened.
Legs & Feet
The kangaroo has two powerful hind legs with long narrow feet with four toes each. Its feet have soft pads, like that of a cat or dog. The first toe no longer plays an important role. The second toe is large and strong with a massive claw. It is used to provide traction when it is hopping. The third and fourth toes are fused, covered by skin, and have two small claws. The kangaroo used these two smaller toes for grooming.
The kangaroo uses its powerful hind legs for hopping. This is its primary means of locomotion. It has extraordinarily large and long Achilles tendons that store elastic energy used to assist it in hopping. (In the photograph you will notice the huge tendon behind its shin-bone).
A kangaroo usually moves both hind legs together. But can move them independently when required. The independent movement of its legs occurs when the animal is turning while hopping when it places one leg slightly in front of the other to execute a turn.
Because the kangaroo hops using 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.
While highly efficient at higher speeds, the kangaroo's hind legs are ineffective at low speeds and hardly used. It uses pentapedaling locomotion at slow speeds.
A kangaroo can't move backwards. It can make very limited hops backwards when fighting. It cannot, however, actually do so as a means of locomotion. Yes, a kangaroo can sit using its hind legs and tail.
The kangaroo also uses its feet as an alarm. It does so by 'foot thumping' one or both of its feet. It is not certain if this behaviour is to alert other kangaroos of danger or as a warning to a predator to stay away, or both.
The kangaroo's large thick tail serves many useful purposes. Without it, a kangaroo wouldn't be able to stand up, hop or move at slow speeds. It is also where a kangaroo stores its excess fat for use in times of hardship. When a kangaroo stands, its tail acts as the third point of a tripod and prevents it from toppling over. The tail also serves a similar purpose when a kangaroo springs up from a standstill position. While hopping, the tail acts are a counterbalance to its body, preventing the kangaroo from tipping forward. Contrary to popular belief, the kangaroo does not use its tail as a rudder.
At slow speeds, the tail is a vital part of its pentapedaling movement. The kangaroo also stands up on its tail, carrying its full weight on it, when it is fighting.
Kangaroos are most active around dawn and dusk. They move around in small social groups called 'mobs' or 'troops'. A kangaroo's lifespan is between 6 to 27 years. Surprisingly kangaroos are also excellent swimmers.
Kangaroo - Habitat Where Do Kangaroos Live?
Kangaroos are found throughout the Australian mainland and on the island of Tasmania. They live in temperate to hot climates and are not found in areas with snow. The red kangaroo lives in the arid and semi-arid interior of Australia. It prefers open plains, grasslands, and desert with some trees for shelter from the hot sun. The eastern grey kangaroo lives in more moist scrub-lands of eastern, southern and south-western Australia. The western grey kangaroo is found throughout the southern parts of Australia and lives in grasslands and open woodlands. The antilopine kangaroo lives in topical woodlands in the northern parts of Australia where there is grass beneath the forest canopy.
Kangaroos are herbivores. They eat mostly grass. Some like the Red Kangaroo also eat the leaves and shrubs.
Do Kangaroos Fart? Yes - Environmentally Friendly Ones
A kangaroo produces almost no methane (Ch4) gas which is produced in large quantities by cattle and sheep through exhaling, burping and to a lesser extent by farting. The kangaroo's digestive system has evolved to convert the hydrogen by-products of digestion to acetate, which is then absorbed and used to provide energy. The kangaroo releases carbon dioxide (CO2) instead, which is 23 times less harmful to the environment than methane.
Kangaroos prefer to feed at night but also graze early in the morning and late evening when it's cool. They rest in the shade during the day.
The Kangaroo has a chambered stomach. Its U-shaped fore-stomach helps it digest fibrous plant material too tough for even goats to handle. Its stomach is more similar to that of a horse than cattle. The kangaroo regurgitates its food, chews it again and swallows it. This extra munching breaks down the rough fibres of their diet and greatly improves its digestion.
The Kangaroo is well adapted to the dry, hot Australian climate. It needs very little water, extracting moisture it needs from its usual diet of grasses and shrubs. A kangaroo requires only 13% of the water required by a sheep. It can survive for months without drinking.
Kangaroos have an excellent sense of the weather and have been known to detect rainfall as far as 20 kilometres away and head towards it.
The kangaroo reaches sexual maturity at around the ages of 16 months for females and 24 months for males. They have no fixed breeding period, but they mate more often when food is plentiful than during periods when food is scarce.
As with all marsupials, the female kangaroo has three vaginas and two uteruses (uteri). The two outermost vaginas are used for sperm transportation to the two uteruses. Babies are born through the middle one. (See photo). By contrast, female placental mammals have only one uterus and one vagina.
The male kangaroo has a two-pronged penis located behind its scrotum. (Most animals have the penis located in front). This two-pronged structure enables the male to inseminate the two vaginas of the female kangaroo. When flaccid, the penis is withdrawn into the animal's body.
The gestation period for a kangaroo is approximately 30 days and varies amongst the different types of kangaroos.
The newborn kangaroo, no larger than a jelly-bean (2 cm) and weighing less than one gram, soon emerges from the birth canal. It is born blind, hairless, with stumpy forelimb and hardly any trace of its hind legs. Using its little forelimbs in a swimming motion, the young joey crawls up its mother's fur to the pouch. Once inside its mother's pouch, the joey quickly attaches itself firmly to one of four nipples in the pouch.
Once it has attached itself to its mother's nipple, the young joey will stay hidden for up to six and a half months. Then it will start to tentatively pop its head out of its mother's pouch and observe the world around it. About two weeks later, it will have gained enough confidence to venture out of the pouch and hop about close to its mother. However, if frightened, it will immediately jump back into the safety of the pouch. By the time it is about 8 months old, the joey no longer uses its mother's pouch.
Do They Throw Their Babies Away? Fact or Fiction?
The answer is yes, and no.
No, kangaroos do not physically throw their babies at predators. Their arms are too short and not strong enough to do that. However, recent scientific research has confirmed that when a female kangaroo is in a life-threatening situation with a predator, she may expel her offspring from her pouch, thereby drawing the approaching predator to the young and allowing the female to escape. Considering the strong muscular control female kangaroos have over their pouches, this eviction seems to be behavioural rather than accidental.
From a biological perspective, this approach is sound. By sacrificing her young, the mother saves herself, rather them both mother and offspring falling prey to the predator. She can then go on to produce more young.
Kangaroo - Fighting (Boxing)
Kangaroos fight less than most other types of herbivores.
These fights usually occur over mating rights and are more ritualistic than aggressive. A male kangaroo fights by kicking its opponent with its powerful hind legs and hitting and clawing with its front paws (which have sharp claws). Very rarely do kangaroos hurt each other during fights.
Contrary to popular folklore kangaroos do not punch or box like humans do.
In the past kangaroos were sometimes dressed up in boxing gloves and made to fight humans. This cruel practice is now banned.
Kangaroo - Swimming
Surprisingly, kangaroos are excellent swimmers. They usually live in dry areas with few large bodies of water; however they are very confident in water. There are many recorded sightings of kangaroos swimming in the sea and also fleeing into watering holes and rivers when threatened.
The kangaroo swims by 'dog-paddling' with all four limbs. It can swim at a reasonable speed. Unlike when it hops where it moves both rear legs together while swimming its moves them independently.
Kangaroo - Predators and Threats
Being large animals with powerful clawed feet and powerful kicks, kangaroos do not have any natural predators. Young animals may occasionally fall prey to eagles and dingoes.
Both domestic and wild dogs also attack kangaroos. The kangaroo is a good swimmer, and if pursued by a predator, it may flee into waterways and use its clawed forepaws to grab its assailant and hold it underwater till it drowns.
The major causes of red kangaroo fatalities are droughts, motor vehicle road kills, hunting and intentional culling by governments.
Kangaroo - Conservation Status Is the Kangaroo Endangered?
The Australian government estimates that there are 50-60 million kangaroos. Because of their large numbers and because they can sometimes cause serious crop damage and deplete farmer's water reserves the government allows limited kangaroo culling and harvesting. Permits are issued for the killing of 1-2 million animals each year.
The kangaroo is not considered to be threatened and is listed by the ICUN as an animal of "least concern".
Extinct Kangaroo Kangaroos that Dies Out
The procoptodon was a giant short-faced kangaroo that stood about 2m tall and weighed as much as 240kg. It was too heavy to hope and probably walked on its hind legs. It lived in semi-arid areas of South Australia and New South Wales and ate a diet of leaves from trees and shrubs.
The procoptodons became extinct between 45,000 and 18,000 years ago. They seem to have become extinct after the arrival of humans. Their extinction may have been caused by human hunting, or by human fire-based deforestation in Australia.
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