Koala

   Phascolarctos cinereus

Phascolarctos cinereus

A typical koala has long thick grey fur often with chocolate-brown highlights on the back and forearms and has a prominently light-coloured ventral side and fluffy white ear tufts. General weights are 12 kg (26 lb) for males and 8.5 kg (19 lb) for females. The origins of the koala are unclear, although almost certainly they descended from terrestrial wombat-like animals. The koala is broadly similar in appearance to the wombat (their closest living relatives), but has a thicker coat, much larger ears and longer limbs. Its large, sharp
claws assist with climbing tree trunks. The koala like the wombat is also the only marsupials in Australia to have no tail. The koala can be found in southeastern Australia SA, Vic, NSW and Qld. The Northern Territory, Western Australia and Tasmania have no koala populations.

Breeding

This animal becomes sexually mature at 2 years of age and mating is during the summer months (December through to March). Females produce 1 young per year and are capable of doing so until 14 years of age. The gestation period is 35 days and twins are very rare. Young spend up to 6 months in the pouch and are then gradually weaned. Once weaning commences the young feed on small amounts of faeces from the mother called ‘pap’. This builds up microorganism levels in the young koala gut ready for them to digest eucalyptus leaves. Koalas have no native predators but chlamydia in high-density populations can lead to infertility. Overpopulation and thus defoliation of trees from heavy feeding is a problem. This results in tree death, limited food supply and a decrease in population.

Behaviour

It is generally a silent animal, but males have a very loud advertising call that can be heard from almost a kilometre away during the breeding season. When under stress, koalas may issue a loud cry, which has been reported as similar to that of a human baby. There is little reliable information about the lifespan of the koala, but in captivity, they have been observed to reach the age of 18 years. Koalas will normally only come to the ground of a night to move to other trees to feed on. Due to the low level of energy in the koala’s diet, they tend to only be active for 2-4 hours of the day and sleep for the remainder of the day.

Diet

The koala feeds only on Eucalyptus or gum tree leaves, of which there are hundreds of species of this tree found around Australia. Individual animals tend to favour some species and this will vary at different times of the year.

Status

Common. The range of this animal is changing due to changes in the environment such as urban spread and reduction of food sources through land clearing. This changes the dynamics of populations and can also lead to populations becoming separated into small areas. This makes migration for young males hard and limits the total genetic pool within the species.