Habitat Ecology Information
What’s Lurking In Your Backyard? – #20 Koala
This series looks at the variety of fauna that may be found in the suburban backyard or local reserve and the diversity may be surprising to some people. The obvious fauna are the vast array of birds that are readily seen by day and some by night, but there are numerous species that are nocturnal. Some of these nocturnal species people are familiar with as they tramp across the roof at night with what sounds like hobnail boots on, or they hear fighting in the backyard over food and territory. Others are cryptic and may only be seen infrequently when they enter the house for warmth and shelter. Each week I will highlight a different species that may be found in and around Melbourne’s backyards, parks and reserves, some may be familiar others less so.
Although the Koala is one of Australia’s most iconic native animals and probably the most recognisable it is not a common species in and around the suburban areas of Melbourne, but can often be seen on the outer fringes forests and woodlands. Don’t be confused though the Koala is not a bear and any reference to it, as one is incorrect. The name Koala is derived from the Aboriginal name given to them, which means “No Drink”. This is because much of the Koala’s water comes from the leaves it consumes and therefore it rarely comes to the ground to drink. However they will drink water when necessary.
The Koala can be found up and down the east coast of Australia from below Cape York to South Australia. Koalas are absent from the other states and Northern Territory and those on Kangaroo Island like the ones in South Australia are derived from Victorian animals. There are said to be two species of Koala but this is in debate. There are however variations in the species across its range with those in Victoria being larger than their northern cousins.
Koalas are an arboreal mammal, grey in colour with white markings around the ears and underside, also a brown tinge to the head and back. Variations also occur across its range. They have sharp claws to enable themselves to climb a variety of trees with the climbing aided by an opposable thumb like humans. Their diet consisting almost entirely of the foliage from Eucalypt species. The range of species eaten by a Koala will depend open the location the animal is found. Usually though there is a range of 4-6 eucalypt species that are available for them to utilise depending on seasonal variation within the tree and its general availability within the forest type that the Koala is inhabiting. The Koalas tendency to sleep for much of the day is a result of its diet. The leaves that they eat take a long time to digest.
Koalas are a marsupial and therefore have a pouch. However in the Koala like its relative the Wombat the pouch faces backwards not forwards as in Kangaroos etc. The female Koala reaches maturity after 2-3 years whilst the male this is 3-4 years. The Koala produces one offspring annually and after a 35-day gestation period the young joey will crawl into the pouch and attach themselves to a teat where they will stay for 6 months sucking on milk before leaving the pouch to ride on the mothers backs. The young generally disperse after 12 months.
Habitat loss and over population are the tow issues affecting the conservation of this species depending on were it is found. In Victoria and South Australia it is creating issues due it over population whilst in Queensland and NSW habitat fragmentation is causing a decline in the species.
© Habitat Ecology 2012