@robotslenderman You’re incorrect on multiple counts.
The tree that koalas eat is the most common one in Australia - FALSE As @shoresoftheshadowlands suggests, koalas are very particular in the types of eucalyptus that they eat. Certainly Eucalyptus and sister genus Melaleuca make up the most of the trees in Australian sclerophylous forests, but koalas will only browse on new-to-young leaves of three particular species (forest grey gum Eucalyptus tereticornis, river red gum E. camaldulensis, and tallwood E. microcorys). They need mature, healthy trees to survive, and they are fiercely territorial over them, meaning that their intraspecies interactions keeps the population at a low density over a huge area.
This is further complicated by the rate of clearing. You said ‘Australia would have to be a complete wasteland’ and guess what, you’re right on that and that alone. Australia is mostly desert. Forests that can support koalas are limited to the edges of the East and South coasts, and a tiny band in the South-West. See how limited the greens (forests) are on this map? Yeah, Australia is indeed mostly wasteland.
These forests are being cleared at unprecedented rates for agriculture, mining, and development. Here’s a handy map of the percentage of original habitat remaining as of 2016 - we’ve cleared an additional ~400,000 hectares of what little remained since then. Australia has one of the worst deforestation rates in the world. See how closely the cleared areas map up with the forest habitats? That’s because that areas that can support forests are also prime agriculture and living areas. There is so little suitable habitat left for koalas, and the quality of this habitat is degrading at an alarming rate - drought is causing widespread diebacks of mature forests, and exacerbating the intensity of fires.
The remaining koala population is now so fragmented that there has been serious inbreeding problems, not to mention the number of koala fatalities because dispersing subadults or adults trying to widen their foraging territory to support themselves get hit by cars or attacked by dogs and foxes. This inbreeding has lead to immunosuppression, which in turn has caused huge disease outbreaks like chalmydia that everyone likes to joke about - but it’s no joke to koalas.
The bushfires are bad, but they’re not that bad - FALSE In my spare time, what little of it there is, I’m a firefighter with one of the longest running brigades in the country, having almost a century of operation. We have a huge wealth of historical records. More then that, my day job allows me access to a huge database of environmental records as well. Looking at both of these, I can tell you, these fires are nothing short of monumental. The 2019 Amazon fires burned through approximately ~900,000 hectares. The fires on the East coast of Australia right now? They have burned almost 3 million hectares. That’s 3,000,000hA of habitat. They have been unseasonably intense, and it’s doubtful that these forests can recover due to the ongoing drought. Whilst sclerophyous forests can take regular low intensity burns, and maybe one or two higher intensity burns spread over a few years in good growing conditions, they cannot survive repeated high intensity burns in short intervals. That is exactly what’s happening. These fires are only going to get more frequent and more intense.
80,000 isn’t functionally extinct - FALSE The estimates of the exact number of koalas left in the wild fluctuate wildly. An optimistic estimate puts the numbers near ~100,000, but a more realistic estimate puts their numbers as low as ~40,000 and dropping rapidly. This is a lot of animals, but recall above that their population is so fragmented and they cannot safely travel between populations. The remaining pockets are terribly inbred and disease ridden. They are also comparatively slow to reproduce, often having only a single young per year in good conditions - and these are not good conditions. This lack of genetic diversity also contributes to the risk of a species being functionally extinct - a healthy population has a healthy genetic pool, which fortifies it against diseases or deleterious mutations spreading rapidly to fixation. If you don’t think it’s that serious, the reason Tasmanian Devil Facial Tumor disease is so prevalent is due to the extreme relatedness of Tasmanian devil populations, meaning that there is little to no genetic resistance to this brutal disease. Something like that could very likely arise in the koalas and it would be devastating.
TL,DR; The heavily fragmented, inbred, environmentally stressed koala population has been dealt a massive blow by the recent unprecedented, widespread bushfires and is unlikely to recover from this without serious and ongoing change on several fronts including land management, climate change, and conservation legislation.
theartofmadeline
kaledo-art
turnnoffyourmind
prguitarman
izzy806
