How does a Koala eat tough eucalyptus leaves?

Answer 1

Eucalyptus leaves are tough, toxic and low in nutrition, but the koala's digestive system is capable of removing the toxins, filtering them out by the liver. The caecum, which comes off the main intestine, has millions of micro-organisms which break down the fibrous eucalyptus leaves, changing them into digestible nutrients and thus making them easier for the koala to absorb.

Answer 2

Koalas, which are marsupials (not bears), occupy a unique niche in the Australian bush ecosystem. Apart from the greater glider, the koala is the only other marsupial which lives almost exclusively on eucalyptus leaves.

Koalas get all their nutrients and water requirements from gum leaves. Koalas consume about 200-500 grams of eucalyptus leaves every day, from about a dozen of their "preferred" varieties, in order to meet their energy requirements. Eucalyptus leaves contain approximately 50% water, 18% fibre, 13% tannins, 8% fat, 5% carbohydrates, 4% protein and 2% minerals. Koalas have been known to also eat the buds, flowers and bark of their particular preferred species, while dirt also seems to supplement mineral deficiencies.

Eucalyptus leaves are tough, toxic and low in nutrition, but the koala has a uniquely adapted digestive system which is capable of removing the toxins, filtering them out by the liver. The caecum completes the process by changing the eucalyptus leaves into digestible nutrients. The caecum is similar to the human appendix.

Baby koalas, called joeys, drink mother's milk during their first 6-7 months of life. After 30 weeks, the mother produces a substance called pap. This substance is actually a specialised form of the mother's droppings which, having passed through her digestive system, give the joey the enzymes it needs to be able to start digesting the tough gum leaves, making an easier transition for the baby koala to start eating eucalyptus leaves.

Answer 3

Koalas nip the leaves from the tree with their sharp front incisors, then chew the leaves up with their broad, sharp molars at the back.

Eucalyptus leaves are tough, toxic and low in nutrition, but the koala has a uniquely adapted digestive system which is capable of detoxifying the leaves, filtering them out by the liver. The caecum completes the process by changing the eucalyptus leaves into digestible nutrients. The caecum is similar to the human appendix, but much longer - around 2 metres in length. The bacteria in the caecum is what breaks down the fibre into a substance which is more readily absorbed by the koala.

Koalas have a very slow metabolic rate which enables the food to stay in the gut for longer, in order to maximise the amount of energy the koala gets from it.

Answer 4

Koalas eat eucalyptus leaves because they are specially adapted for this purpose. Koalas live in eucalyptus trees and eat only a few types of gum leaves from which they get all nutrients and water requirements. They also occasionally eat the gum tree blossoms. Eucalyptus leaves are tough, toxic and low in nutrition, but the koala's digestive system is able to remove the toxins, filtering them out by the liver. The caecum, which is similar to the human appendix, changes the eucalyptus leaves into digestible nutrients.

While there are hundreds of different eucalyptus species in Australia, koalas eat from only about 60 of the species, consuming about half a kilogram of eucalyptus leaves every day.

Answer 5

Koalas have a very slow metabolic rate which enables the food to stay in the gut for longer, in order to maximise the amount of energy the koala gets from it.

Koalas live almost exclusively on eucalyptus leaves. Eucalyptus leaves are tough, toxic and low in nutrition, and most animals cannot eat them. The koala has a uniquely adapted digestive system which is capable of detoxifying the leaves, filtering them out by the liver. The caecum completes the process by changing the eucalyptus leaves into digestible nutrients. The caecum is similar to the human appendix, but much longer - around 1.3 to 2 metres in length. The bacteria in the caecum is what breaks down the fibre into a substance which is more readily absorbed by the koala.

Answer 6

Because that is the vegetational environment in which they evolved