Koalas are herbivorous marsupials that initially originated from Australia. Mainly found in the coastal regions, the koala is closely related to the wombat and is the only surviving member of the family Phascolarctidae. In Australia, the animal lives in areas such as Queensland, New South Wales, South Australia, and Victoria. Some of the characteristics that make this animal easily recognizable includes things like a sturdy body, absence of a tail, spoon-shaped nose, and large fluffy ears with a round shape. In terms of size, koalas have an average body length of between 24 inches and 33 inches with an average weight of between 9 pounds and 13 pounds. The color of their fur varies from a chocolate brown to a silver grey. Those living in the southern parts are slightly heavier and darker in color compared to their northern counterparts. Koalas prefer to live in open woodlands where eucalyptus is the dominant tree species.
Diet of Koalas
Koalas are strictly herbivorous animals, that is, their diet consists of vegetation only. As stated earlier, the animals prefer to live in woodlands where eucalyptus trees are plentiful. The reason for this particular preference is that the animals’ diet is made up, almost entirely, of eucalyptus leaves. Occasionally, the animals may be found in woodlands eating leaves of trees such as Acacia, Melaleuca, Leptospermum, Callitris, and Allocasuarina.
Currently, there are about 600 known species of the eucalyptus trees. Out of these species, koalas have a preference for about thirty of them. The reason for preferring these thirty species has to do with the relatively higher protein content and low amounts of lignin and fiber. Some of the favorite species include Eucalyptus microcorys, Eucalyptus tereticornis, and Eucalyptus camaldulensis. About 20% of their diet is made up of leaves from these three plants. In a day, a koala eats between 7 and 17 ounces of leaves.
Special Dietary Adaptations of Koalas
The diet of gum leaves is not safe for consumption by other animals. However, koalas have some special adaptations in their bodies and in their behavior that enable them to survive on this diet. One of the adaptations is the presence of a special section in the intestine, known as a caecum, which branches off from the main intestine. This chamber is bigger and longer than other intestines. The purpose of this chamber is to ensure that the gum leaves are broken down by the millions of microorganisms, which makes them easier for absorption. These animals also produce a substance known as cytochrome P450 to break down the toxins. The water in the leaves ensures that they do not need to drink that much water. Their teeth are also sharp and specially designed for eating eucalyptus leaves.
Behaviorally, the animals may spend up to 22 hours of a day sleeping with activity kept to a minimum. This behavior is due to the limited amount of nutrients that they get from the leaves. As such, they have no choice but to conserve energy.