Kangaroo

Kangaroos are the largest Marsupials alive today. They are now native to the continent of Australia. There are four sub-kinds in the kangaroo baramin -- the Western Grey Kangaroo, the Eastern Grey Kangaroo, the Red Kangaroo, and the Antilopine Kangaroo -- or at least sixty-nine species according to evolutionary views, which include wallabies and tree-kangaroos.

Description

Kangaroos have large ears on top of their small heads, a long snout, and short arms with clawed fingers. Their legs are strong, powerful, and are made for leaping. Their feet have four toes at the end of elongated metatarsi that they rest on when standing. They also have a powerful, thick tail that is used as support when standing, a third-leg when walking slowly, and for counterbalance while leaping. Like all Marsupials, female kangaroos have a pouch on their stomachs in which they carry their young.

Diet

Kangaroos are herbivores, eating grass, roots, and shrubs. They have a chambered stomach similar to sheep and cattle. They are able to regurgitate their food, chew it again as cud, and then swallow it for digestion.

Social Order

Kangaroos travel in mobs of about ten or more males and females. The leader of the mob, called a "boomer", is a male determined by age and size. The boomer has access to females in his mob for mating and will wander around the mob intimidating any other males who try to mate with his harem.

Reproduction

Female kangaroos usually only have one baby kangaroo (called a "joey") at a time. The newborn joey weighs as little as .03 ounces when first born, after which it crawls into its mothers pouch where it will nurse, grow, and develop. Red Kangaroo joeys will stay in their mothers pouch for about eight months and Grey Kangaroo joeys stay in there for about one year.

Development of the Young in the Pouch

Kangaroos have adapted to the varied conditions across Australia in many ways. One of the most unusual, is the way females of some species can delay the progress of pregnancy. In this way the female is ready to give birth to a replacement for the young in her pouch if it dies early, or within a week of when it permanently leaves the pouch. This ability to delay births means that there can be up to 12 months between a mating and the birth of the young one resulting from that mating (when the normal gestation period is less than 35 days). It also means that the species can best respond to periods of drought and plenty.

Species which have this unusual ability normally mate again soon after the female gives birth. The tiny newly born kangaroo (less than 25 mm long) moves unaided into its mother's pouch and attaches itself to one of four teats. During the early stages of pouch life the young is permanently attached to the teat, but as it matures and begins to grow hair it also develops the ability to release and reattach itself to the teat.

In the late stages of pouch life, once it has a thin covering of fur, the young one begins to explore the outside world for increasing lengths of time until eventually it is old enough to be excluded permanently from the pouch. Complete weaning may take a number of months more after the young has permanently left the pouch. If the mother gives birth during this time, the newborn young will attach itself to a different teat to that being used by the older young. It is remarkable that when this happens the mother produces two different kinds of milk for the two different-aged young.

External Links

• Kangaroo facts
• Answers About Kangaroos
• How did animals get from the Ark to places such as Australia?