Other Information

http://video.nationalgeographic.com/video/player/kids/animals-pets-kids/mammals-kids/koala-saved-kids.html

Koalas are nocturnal and spend up to 18 hours a day sleeping.

While koalas spend most of their lives in trees, they do occasionally climb down to get a drink of water or to change trees if the next one over is too far away for them to jump.

The koala is not yet classified as endangered, but it is close to it due to the large amounts of deforestation in its prime habitats.

Adult male koalas can be 50% larger than adult females.

Koalas have vertically slit pupils instead of circular, as in other marsupials.

Reproductive System

The koala is a marsupial, so it carries its young in a pouch. Koalas, however, have a pouch on their backs and not their bellies like some other marsupials.

During the mating season the males develop a deep bellowing grunt to attract females while they usually just have a high-pitched chirping sound.

The gestation period of a pregnant female is from 34-36 days and they usually have only one joey per year. When it is born, the joey is about the size of a jellybean.

The young joey stays in its mother's pouch for about a year before starting out on its own and reaches full maturity at about two years old.

Digestive System

The entire digestive system of a koala is, on average, about 305 cm. long.

As an herbivore, koalas eat only the leaves of some of the 24 different species of Eucalyptus trees and select other stems or buds. In addition, most of the water they need to survive comes from the leaves they eat.

In order to digest their diet of plant matter, koalas are dependent on helpful bacteria in their digestive tracts.

Koalas also have cheek pouches to hold extra stems or leaves while they eat.

Nervous System/Respiratory System/Circulatory System

Koalas have a nervous system much like that of other mammals, other than having an exceptionally small brain.

The respiratory system that a koala has is much like that of other mammals except that it lacks "swell bodies" which are glands that regulate air flow between the left and right nasal cavities.

Like most mammals, koalas have a four-chambered heart and have a closed circulatory system, meaning their blood flows through veins. Also, their normal resting heart rate is about 90 beats per minute.

Integumentary and Skeletal/Muscular Systems

Koalas have a dense, wooly coat of ash-colored to dark brown and white fur.
Male koalas are very territorial and have a specialized brown scent gland on their chest that they use to rub their scent on trees to deter other males.

Koalas are vertebrates so they have a backbone.

The koala is an herbivore so it only eats plant matter.
Therefore, it has specialized teeth in its skull to help grind up the plant fiber in eucalyptus leaves.

External Features

Studies have shown that koalas have the highest degree of insulation of any marsupial because of their thick fur. Also, the koala has a vestigial tail on the end of its back which is a very small, hardly noticeable, tail.

http://bioweb.uwlax.edu/bio203/s2007/mundt_meli/adaptation.htm

Classification of a Koala

Scientific name: Phasolarctos cinereus
    Kingdom: Animalia
        Phylum: Chordata
              Class: Mammalia
                  Order: Diprotodontia
                      Family: Phascolarctidae
                          Genus: Phascolarctos
                              Species: cinereus

http://bioweb.uwlax.edu/bio203/s2007/mundt_meli/classification.htm