Koala description and biology

The koala is a marsupial mammal which means it has a pouch and suckles its young. Koalas have grey fur and have large rounded ears on top of a big head. They are usually only approximately 60-85cm tall with a stout body and short legs used for climbing. Their size, colouring and shape vary depending on geographic range, for example, southern koalas have thicker and darker fur and are generally larger than those in Queensland which have short, paler grey fur. Males weigh between 6-10 kilograms compared to females who are slightly smaller and range between 5-7 kilograms. Males can also be distinguished by a small bare patch in the middle of the chest which is often stained brown, especially during breeding season. Koalas are closely related to the wombat.

Koalas are considered arboreal (tree dwelling) mammals however they do descend to the ground to move from one tree to the other. Being mostly nocturnal, a koala will spend most of its time sleeping in branches throughout the day and feed mostly at dusk (they sleep for around 18 hours each day). Although koalas are mostly active at night, they will move around during the day. They will move if they are disturbed, if they are too hot, too cold or simply to find a new feed tree. During the day, they tend to move mid-morning (10am-11am) and late afternoon (3pm-4pm).

 

Koalas are mainly solitary animals except during the mating season. They communicate through a variety of calls consisting of bellows, grunts and low pitched snarls. These calls are often heard during the mating season. 
 

The breeding season is generally from August to December with majority of young being born in December/January. Females are sexually mature at approximately two years of age and can produce one young per year. Males breed from the age of three to four years. A koala in the wild will live for approximately 10-14 years, however the average life span is often significantly reduced in suburban areas due to increased threats.

 

After conception, gestation lasts 35 days before the joey is born which is only 2cm in length and are totally hairless, without ears and are blind. After birth, the joey makes its way to to the mothers pouch where it attaches itself to her teats. Joeys remain in the pouch for approximately five to six months relying entirely on the mother's milk. They first emerge from the pouch after five to six months. After weaning, the mother produces a special form of faeces, called 'pap'. Once consumed, pap provides the infant with important gut bacteria necessary to digest eucalypt leaves. 

 

Koalas are specialist leaf eaters, feeding predominantly, but not exclusively, on eucalypt leaves. They  will also feed on other closely related species such as Lophostemon (eg swamp box) and Corymbia (bloodwoods), as well as Melaleucas (paperbarks) Callistemon. Koalas show a strong preference for the eucalypt species that row in their local area. The main trees suitable for koalas in the Redlands are:

 

The name ‘koala’ is an Aboriginal word meaning ‘no drink’, obtaining most of their water from eucalypt leaves. Koalas will however come down to drink in times of drought, extreme heat and if they are sick.

 

Eucalyptus trees and native plants can be purchased at IndigiScapes Centre, 17 Runnymede Rd, Capalaba.