|
Of all the mammals that have a pouch, the kangaroo is the most well known. The family name is called Macropodidae. Captain James Cook, an English explorer in the 1800's came to Australia and asked the Endeavor River aborigines what the name of the animal with the pouch was and they told him kangaroo. The word kangaroo means "I do not know". These mammals have been known since as the kangaroo. There is evidence that kangaroos lived in Australia during the Miocene Epoch, some l5 million years ago. The kangaroos during that time were giant ones that stood to l0 feet tall and weighed almost 450 pounds.
The largest of the kangaroos is the Great Kangaroo or Forester. The female is called the "flyer" and is smaller than the male that is called the "boomer" and may be up to seven feet tall. This kangaroo hops on powerful hind limbs and his tail serves as a prop to help him leap even higher. He lives in southwestern Australia, Tasmania, New South Wales and in Queensland. The kangaroos are of two families, the Macropodidae and Potoroidae. Macropus giganteus is the classification of the red kangaroo. There are two species of the gray kangaroo classified as Macropus giganteus and Macropus fuliginosus. The Hypsiprymnodon moschatus is known the as musky rat-kangaroo, and the bettong as Bettongia penicillata. The ring-tailed rock wallaby is classified as Petrogale xanthopus.
There are three groups of the Great Kangaroos. The Great Gray Kangaroo, or Forester is found in forests and brush country of southwestern Australia and Queensland. The Great Kangaroo is the largest and can stand up to seven feel high and will weight almost two pounds as an adult. He is known as the "boomer", while the female is known as the "flyer" and is much smaller. This trait is known as sexual dimorphism. He has powerful and long hind limbs that allow him to hop and a long tail that serves as a prop to enable him to jump very high. The Great Kangaroo can jump from five to ten feet at one time and can cover up to twenty feet in one leap.
The Tasmanian Forester is the only large species of kangaroo in Tasmania. The fur is longer and coarser and reddish brown than the mainland gray kangaroos. This kangaroo is very common in Tasmania but is a protected species. These can be located in the center, east coast areas but are more common in the northeast of Tasmania.
The third group of the Great Kangaroos is the Red Kangaroo that lives in the plans and open forests of Australia. The male is a beautiful color of the shade of red win. These kangaroos are very colorful, powerful and graceful. The female is a very soft smoky-blue and has the name of the "blue flyer."
The Tree Kangaroo is known as Dendrolagus and likes the trees better than the ground area. He has the long hind legs as other kangaroos but they are not as long or as broad and the pads on his feet are very rough as he climbs. He has a long thin tail with a brush at the tip that helps in his balance and as a sort of rudder for leaping in trees. He thrives on eating creepers, ferns, fruits and white cedar. The natives hunt these kangaroos for food. He prefers the forest especially in the north of Queensland. The two species of Tree Kangaroos living in Australia are the Dusky Tree Kangaroo and Lumholtz's Tree Kangaroo. Three are four in New Guinea
The smallest of all kangaroos is the Musk Kangaroo called Hypsiprymnodon. This kangaroo is only about eighteen inches including his tail that has no hair and has scales on the skin. Musk Kangaroo will have a musky order, are reddish brown and very shy. They like to eat grubs, insects, tuberous roots, berries and fruits. This kangaroo does not hop.
Kangaroos on the average will have small heads, large ears and small front feet. The front feet have five digits and the back will have four with a sharp claw on each of the hind feet. Males are larger than females. The coloring of most kangaroos is such that they are able to blend in with their surroundings. They are different from other marsupials as they use the hind legs and tail for the purpose of hopping. The kangaroo is able to use all four legs and can use the hind legs for hopping. The kangaroo's heavy, muscular tail is also important for locomotion. It serves as a counterbalance and a rudder during hopping, and provides support when the animal sits.
Kangaroos can easily digest plant matter high in fiber and low in protein as they have multi-chambered stomachs that contain bacteria. This bacteria can break down plant cell walls and releases the nutrition content in the cells. Kangaroos in various species will mostly be herbivores or what is known as plant-eaters. Some species like to graze such as the red and gray kangaroos, some others as the tree kangaroo like leaves, twigs and shoots on trees. The smaller kangaroos such as the rat-kangaroos will eat small animals and plants. The kangaroos dwelling in forests will dine on carrion, worms, insects, tree gum residues and fungi.
The female kangaroo has a type of yolk sac in the womb instead of the fully developed placenta. Nutrients from this yolk sac are absorbed from the embryo. When birth occurs the baby kangaroo is still in an embryo like form having developed forelimbs. It will only weigh about 0.04 ounces and will crawl to the abdominal pouch then attack to a nipple to suck.
The embryo stays in this pouch and sucks for a few months until it can move around and is full developed. The embyro is called a joey. It can remain in the mother's pouch for six month to one year. It will peak out as the mother hops along to see the outside world. The musky rat-kangaroo is the only kangaroo to produce more than one single young. When the embryo leaves the womb the female can mate again. She can have a fertilized egg in her womb while the young is still in her pouch. An blastocyst is the name given after the fertilized egg stops and becomes a simple, hollow ball of 100 cells. This blastocyst will just stay in the womb until the offspring in the pouch leaves to be on it's own. It is in a state of suspended development. After the offspring lives the pouch the embryo will continue to develop then live the womb and live in the pouch. Embryonic diapause is the name given this feature of reproduction. A female kangaroo can care for up to three litters at one time.
The males of the red and gray kangaroos will form large groups called mobs consisting of at least l0 males and females. Depending on the age and size of the male the hierarchy is formed. A boomer is the name given to the most dominant male. He will have exclusive axcess to the female when mating. Sometimes it can take to ten years for a male to become a boomer. He can be replaced after a year or more by a younger male who takes over his position of dominance. The older male will usually die after being replaced.
Kangaroos can live up to l8 years, although in captivity they will live to around 28 years. Habitat destruction harms the kangaroos more than predators. Farmers and ranchers will poison the larger kangaroos and animals will devour the smaller ones.
| 
