Introduction to Kangaroo
Kangaroo, a mammal native to Australia and nearby islands and introduced into New Zealand. The kangaroo is a marsupial —the female has an abdominal pouch (marsupium) in which it suckles and carries its young. There are more than 50 species of kangaroos.
Kangaroos run by hopping with their powerful hind legs and feet.Are There Different Types of Kangaroos?The two main types are red kangaroos and gray kangaroos. Red kangaroos are the largest marsupials in the world. The males have bright coats of thick, red fur. Females are slightly smaller than the adult males. Their coats have some red, but they are mostly smoky blue. As you might have guessed, gray kangaroos have gray fur. Sometimes it looks more like silver. Of all the marsupials, kangaroos have the largest pouches.
Kangaroos have small, furry heads and pointed snouts. They can turn their long ears from front to back to follow sounds. This helps them listen for danger.
Kangaroos have huge back feet and tiny front feet. It’s not easy for them to move those huge back legs and feet one at a time. So, they don’t run on all four legs the way most animals do. Instead, they run by hopping around, using both of their powerful hind legs and feet.
Great Kangaroos
Great kangaroos are the largest members of the kangaroo family. They usually grow to about five feet (1.5 m) from nose to base of tail. Old males may exceed seven feet (2.1 m). The males are called boomers, or old men ; the females, flyers ; the young, joeys.
How Do Kangaroos Size Up?The kangaroos of Australia come in all different shapes and sizes. Some are very small. Rat kangaroos are the smallest. A full-grown rat kangaroo is smaller than a rabbit. It stands about a foot tall (30 centimeters). Then come the wallabies. Wallabies range in size from 1 to 5 feet (30 to 150 centimeters). Next come the wallaroos. The biggest family members are the red and gray kangaroos.
The red and gray kangaroos are the heaviest, strongest, and tallest marsupials. A red kangaroo can grow taller than any other kangaroo. “Big red” can grow to be 6 feet (1.8 meters) tall.
The red kangaroo is the largest kangaroo. It weighs as much as 190 pounds (86 kg). It inhabits the Australian plains. The eastern gray kangaroo weighs as much as 145 pounds (66 kg). It inhabits open woodlands of the Australian mainland and Tasmania. The euro, or wallaroo, which may be red, gray or black, weighs as much as 100 pounds (45 kg). It is common in Australia's rocky hills. It can survive for months without drinking because its body conserves water very efficiently.
The head of a great kangaroo resembles the head of a deer. A great kangaroo's forelegs and forepaws are small; its hind legs and feet are long and powerful. The toe next to the outer toe on each hind foot is armed with a large, strong claw. The tail is muscular and almost as long as the body. It is used as a prop when the kangaroo is standing and it helps the kangaroo maintain its balance while leaping.
Great kangaroos can attain speeds of up to 50 miles per hour (80 km/h) for short distances. Adults can leap as far as 30 feet (9 m), reaching a height of 10 feet (3 m). Great kangaroos live in herds, called mobs, which number from 5 to 100 animals. They eat grass, the leaves of shrubs and trees, and grains and fruits. The kangaroo has a multichambered stomach and thus can digest plant fiber high in cellulose. In times of drought it can therefore live on many drought-resistant plants other animals cannot digest.
How Far Can Kangaroos Hop?Kangaroos are great hoppers. They do more than little bunny hops. Since kangaroos use their powerful hind legs and long feet to hop, their “hops” are more like “jumps.” They can hop fast and far.
One hop can carry a kangaroo three or four times its own length. The longest hop recorded is 43 feet (13.1 meters). Kangaroos can travel up to 50 miles (80 kilometers) an hour, but they cannot keep that speed up for too long.
When a kangaroo is not hopping, it rests on its big, long tail. The kangaroo uses its tail for pushing off. Its tail helps the kangaroo keep its balance, too.
Why are the Arms and Legs so Different?A kangaroo’s small front legs are used to pull leaves from small plants or to dig into the ground for water. A kangaroo’s hind legs are very strong. They help a kangaroo push its entire body off the ground and into the air. These powerful legs allow the kangaroo to hop over objects equal to its own height.
Kangaroos are gentle animals. But if a kangaroo feels threatened, it uses its hind legs to defend itself. The kangaroo leans back on its long tail and strikes the enemy with its strong hind legs and sharp toenails. A single kangaroo kick can cause great harm to an enemy.
Typically, a kangaroo gives birth to a single joey four to five weeks after mating occurs. The birth of the joey is delayed, however, if there is a joey already occupying the mother's pouch and during periods of drought. In such cases, the embryo goes into dormancy and birth does not occur for as long as 11 months after mating. The newborn—blind, hairless, about one inch (2.5 cm) long and weighing about 1/30th of an ounce (1 g)—crawls to the pouch of its mother and attaches itself to a nipple. It remains attached to the nipple for several weeks, taking milk from the mother. After three months, the infant leaves the pouch for brief periods, diving back headfirst when danger threatens. It leaves the pouch permanently at about eight months, but continues to nurse for a few more months by putting its head inside the pouch. The mother sometimes nurses two young of different ages.
How Big Is a Joey at Birth?A female kangaroo gives birth to a joey one month after mating. She raises it alone. A newborn joey doesn't even look like a kangaroo. At birth, the joey is the size of a lima bean. Its body is mostly head and torso. It has no fur, and it cannot see or hear.
Right after birth, the joey crawls blindly into its mother’s pouch. It attaches itself to a teat and begins to drink its mother’s milk. The pouch is lined with fur. It’s a warm and cozy place to grow. The baby could not survive outside the pouch.
When Does a Joey Leave the Pouch?The joey enters the mother’s pouch head first, almost as if it’s doing a somersault. Once inside its mother’s pouch, the joey turns around. Then it pops its head out of the opening. Mom’s pouch is a safe place to hide!
A joey stays close to its mother until it is 2 or 3 years old. The joey continues to drink its mother’s milk until it is fully grown.
Kangaroos are generally gentle animals, but males sometimes fight each other for the females. Fighting commonly consists of wrestling, boxing, and kicking. Kangaroos can be tamed and trained to box playfully with humans.
The red and eastern gray kangaroos are hunted for their meat and hides. They are also killed by farmers because they eat crops.
Where Can You Spot Kangaroos?Kangaroos are grazing animals. They eat grass and other small plants. Kangaroos usually gather in groups, or “mobs,” of up to a hundred animals. They live in many habitats, such as woodlands and grasslands. They can also be spotted on rocky hills, in deserts, and in trees.
Kangaroos are most active at night or early in the day. During the middle of the day, they rest under shady trees or bushes to stay cool.
Most people don’t think of kangaroos as tree climbers. But one kind enjoys living the high life. Tree kangaroos have smaller hind feet and bigger front feet than other kangaroos. A tree kangaroo is the only kind of kangaroo that can move one back leg at a time. This lets it walk along branches of trees, where it feeds on leaves or fruit. Sometimes a tree kangaroo jumps to the ground from the treetops. To get back into the tree, it jumps up about 20 feet (6.1 meters).
Wallabies and Other Roos
The Wallaby may grow to 4½ feet (1.4 m) long, including a 29-inch (74-cm) tail, but some wallabies are as small as house cats. One of the smallest, the rock wallaby, is noted for its daring leaps across deep, wide chasms. Members of one group of small wallabies are called hare wallabies because they are similar in color and size to the hare. The nail-tailed wallaby is so named because its tail is tipped with a horny spur. Wallabies are hunted for their meat and pelts. Many species of wallabies are threatened or endangered.
Is a Wallaby a Kangaroo “Wannabe”?The “wannabe” is actually a wallaby. Wallabies are part of the same marsupial family as kangaroos. They are all known as macropods. The word macropod means big foot. Wallabies look just like kangaroos, but most of them have smaller bodies and feet.
A rock wallaby hops among the rocks. Rock wallabies have thick, rough pads on the bottoms of their feet. These pads are just like the soles on hiking shoes. The pads protect rock wallabies’ feet and help them grip hard, jagged rocks.
The Tree Kangaroo can leap 40 feet (12 m) from tree to tree. Tree kangaroos typically grow to about four feet (1.2 m) long, including a 24-inch (60-cm) tail. Their forelegs and hind legs are of almost equal length. Many species of tree kangaroos are threatened or endangered.
The Rat-Kangaroo eats insects, worms, and plants. Rat-kangaroos weigh less than eight pounds (3.6 kg). The musky rat-kangaroo is the smallest kangaroo. It grows to about 18 inches (46 cm) in length, including a 7-inch (18-cm) tail. It gives birth to two or three young at a time. Many species of rat-kangaroos are endangered.
What Are Potoroos and Quokkas?The potoroo (POH toh roo) is Australia’s most ancient kind of kangaroo. Potoroos have been around for millions of years. They look like tiny rats. A potoroo is less than 10 inches (25 centimeters) tall. It has dark, grayish-brown fur; a pointed snout; and short, round ears. Potoroos dig for food with their front claws. They hop along the ground and feed on roots, mushrooms, and insects.
Another unusual marsupial is the quokka (KWAH-kuh). It is one of the smallest kangaroos. It is less than 2 feet (60 centimeters) tall. Quokkas are shy animals that also look like rats. Most quokkas live on Rottnest Island, off the southwest coast of Australia. Rottnest is Dutch for rat’s nest. Rottnest Island was so named because explorers thought quokkas were giant rats.
How Did the Wallaroo Get Its Name?Another type of kangaroo is the wallaroo (WAHL uh roo), also called the Euro. The name wallaroo is a combination of wallaby and kangaroo. Wallaroos are larger than wallabies and smaller than gray and red kangaroos. Don’t let their short legs fool you. Their legs may be short, but they are sturdier than the legs of even the biggest kangaroos. Wallaroos are the only kangaroos with bare, black snouts.
You probably won’t see a wallaroo on a hot, sunny day. That’s because wallaroos stay “indoors.” Like other marsupials, wallaroos conserve body fluids by staying in the shade. But wallaroos find their shade in caves and under rock ledges in hilly areas. When a wallaroo gets thirsty, it doesn’t go out looking for a drink. It just digs a water hole in the ground.
Some authorities classify all kangaroos in the family Macropodidae. Others consider rat-kangaroos to be in their own family, Potoroidae. The red kangaroo is Macropus rufus; eastern gray kangaroo, M. giganteus; euro, M. robustus. Rock wallabies are of the genus Petrogale; hare wallabies, of the genus Lagor-chestes; nail-tailed wallabies of the genus Ony-chogalea. Tree kangaroos are of the genus Dendrolagus. Most rat-kangaroos are of the genus Potorous or the genus Bettongia. The musky rat-kangaroo is Hypsiprimnodon moschatus.