Koala around and its head has doubled in size. The eyes begin to open and fine fur grows on the forehead, nape, shoulders, and arms. At 26 weeks, the fully furred animal resembles an adult, and begins to poke its head out of the pouch. As the young koala approaches six months, the mother begins to prepare it for its eucalyptus diet by predigesting the leaves, producing a faecal pap that the joey eats from her cloacum. The pap is quite different in composition from regular faeces, resembling instead the contents of the caecum, which has a high concentration of bacteria.
Koala retrovirus and more pathogenic than KoRVA, because the deleterious effects it causes in its hosts will not be selected against to the extent they would in a virus capable of integrating into the germ line. It is thought that further studying KoRV will allow valuable insight into how endogenous retroviruses develop, evolve, and incorporate themselves into mammalian genomes. Koala retrovirus Koala retrovirus (KoRV) is a retrovirus that is present in many populations of koalas. It has been implicated as the agent of Koala Immune Deficiency Syndrome (KIDS), an AIDS-like immunodeficiency that leaves infected koalas more susceptible to infectious disease and cancers.