Koalas are amazing creatures! These animals have fantastic features to help them survive the harsh Australian environment and are one of the only animals known to have evolved a smaller brain to help them conserve energy! Koalas also have sharp claws to help them climb, enormous noses to help them detect the level of toxins in the leaves they eat, and thick fur to keep them dry in the rain. Although these animals are not considered close to extinction, it is feared that habitat destruction will quickly see this famous Australian put onto the endangered list.
Although this species is listed in the ‘least concern’ category due to it wide distribution there is still concern for the future of the species. The biggest concern for this species is habitat destruction, and forest fragmentation. Another, less well-known problem is the widespread presence of Chlamydia, a disease caused by a pathogenic bacterium. In healthy populations, individuals with the disease are not unhealthy, but when animals are found living in abnormally high concentrations, due to deforestation or bushfires, these same individuals start to show symptoms and become unwell.
In some areas of Australia the numbers of koalas have actually increased in the past 100 years. although millions of koalas were hunted for their beautiful thick fur in the late 19th and early 20th century for the fur trade.
Distribution & Habitat
Koalas are found from North Queensland all the way down the east coast of Australia and around to South Australia. They are generally found in open eucalyptus forests, feeding almost exclusively on eucalyptus leaves. In the inland parts of their range koalas tend to live in trees surrounding watercourses.
Koalas have also been introduced to at least 12 islands off the Australian mainland including: Kangaroo Island, French Island, Phillip Island, and Magnetic Island. This was sometimes done when it was feared that mainland populations may be on the verge of collapse due to the fur trade early last century.
The breeding season is from October to November. During this time the male calls loudly to attract females, an unusual sound in the forest as koalas are usually silent. After only 35 days the female will give birth to one or occasionally two joeys. The small, blind and hairless baby will have to crawl to its mothers backwards facing pouch, which has strong muscles to prevent the joey from falling out. Once inside the pouch the baby will attach to a teat and start to drink its mother’s milk. It will stay hidden in its mother’s pouch for six months. By 12 months of age the joey is permanently out of its mother’s pouch, and by 18-24 months of age it is independent. Koalas are sexually mature at around three years of age and live for about 12 years in the wild.
Koalas feed almost entirely on eucalyptus leaves, but will not eat just any species of eucalypt. In fact, koalas will only eat about 10% of the 600 or so eucalyptus species, and of the 10% of suitable species Koalas will still choose young and juicy leaves to eat. Eucalypt plants are quite high in toxins and as such most mammals will not eat the leaves. Koalas however have taken advantage of the lack of competition for this food source and have adapted their gut to be able to cope with the poison. Koalas need to eat up to 1kg of leaves per day so it is imperative that these particular species are widespread. Koalas seldom drink as they obtain enough water from their leafy diet and the dew they find on leaves in the morning. Koalas may also eat a small amounts of soil to add nutrients to their diet.
Koalas will often rest in a fork of a tree during the day and are often found in the upper canopy of the tree. In cold and wet weather they may take shelter lower down the tree, hunching over to keep themselves warm and dry. Koalas have very thick fur, especially those animals in the colder areas of Australia. The clearing of forests can result in overpopulation of koalas in certain areas and not enough food. Koalas are nocturnal animals, and can spend 18-20 hours sleeping each day.