published on 17 May 2019 in life
Threatened koalas are ‘functionally’ extinct
The koala (Phascolarctos cinereus), the animal that, along with the kangaroo, is the symbol of Australia, is threatened with extinction in that it is a functionally extinct species. According to the estimates of the Australian koala foundation (AKF), the organisation that is engaged in protecting these animals, it is thought that there are now only 80 thousand koalas in Australian territory – a number that is insufficient for them to play a significant role in the environment and guarantee the survival of new generations.
The expression, “functionally extinct” refers to various situations, for example a species whose population has decreased to the point in which it can no longer play a significant role in its ecosystem. Or it can also indicate a species that has totally, or almost, lost its habitat, whose fate is therefore sealed. Lastly, it may indicates a species that is no longer able to reproduce effectively, that is not only giving life to new generations, but also maintaining a certain genetic variability. Besides being lethargic animals (due to their metabolism), a characteristic that reduces the frequency of their mating, many koala populations suffer from consanguinity, a factor that puts the vitality of the species at risk.
The causes of reduction in koala populations, animals who have populated Australia undisturbed for about 30 million years, are of human origin. In the past, these marsupials were hunted for their fur, while now they are threatened by the effects of climate change and deforestation, which are depriving them of their habitat and their food source, the leaves of eucalyptus trees. The rise in temperatures, additionally, leads to extension of periods of draught and increases the risk of bush fires and diseases.