Despite being found only on one continent in the world, many of us appreciate everything koalas have to offer. We celebrated this endearing marsupial earlier this month on Wild Koala Day and have continued the revelries by providing interesting facts throughout the month. Highlighting this iconic Australian mammal is of continued importance as the wild population continues to decrease. According to some estimates, the koala population in Queensland between 1996 and 2016 decreased by as much as 80%. Here, we present some of the leading threats Phascolarctos cinereus face in their bid to survive in the modern world.
A chlamydia epidemic is known to have killed a large number of koalas from 1887 to 1889. This pathogen has threatened the species ever since and has been shown to be the second most common cause for admission to rehabilitation centres.
Image: Mammal by TahliArtPhotography. Public domain via Pixabay.
Bushfires pose a huge threat to koalas, as they regularly destroy the animal’s native habitats, from which koalas are often unable to flee due to their slow movements. Fires have historically caused the human populations of Australia trouble, but with the industrialization that accompanied colonization, more opportunities arose for fires to get out of hand. In the mid-twentieth century technology was developed that has aided in fighting the worst of the fires, meaning that both human settlements as well as natural habitats are more often saved from complete destruction.
Image: Fire by sandid. Public domain via Pixabay.
Like other small mammals and marsupials, the koala is severely affected by the occurrence of drought. This weather phenomenon causes eucalyptus trees to lose leaves, meaning that there are fewer trees for the animals to feed off, leading to starvation and dehydration. Droughts are becoming more common as a result of climate change, consistently impacting negatively the koala population.
Image: Outback by Barni1. Public domain via Pixabay.
The koala retrovirus (KoRV) has been plaguing the species for the last two centuries. The virus is thought to cause koala immune deficiency syndrome (KIDS) which is similar to human AIDS, suppressing the animal’s natural immune system. This makes them more susceptible to illnesses that they might otherwise easily fight off.
Image: Australia by Eiston. Public domain via Pixabay.
In the early twentieth century, the threat to the survival of the species peaked when the marsupial was hunted for its fur. In 1924, 2 million skins were exported, creating a lucrative trade but hunting the animal close to extinction. Hunting bans were imposed and active population management techniques were implemented in southern populations from 1944 onwards. Koala populations in Australia have largely recovered as a result of this proactive engagement.
Image: Bear by attapontom. Public domain via Pixabay.
Habitat destruction is the biggest threat to the species’ survival. Koalas’ natural habitats have largely been reduced over the last century due to an increase in agriculture and urbanization. Native forests are also being used to make wood-based products, resulting in deforestation. The distribution of koalas in Queensland has decreased significantly since the arrival of Europeans. Measures currently taken to combat these issues include marking the species as “vulnerable” and moving key populations to protected areas.
Image: Port Douglas by StreetTalkSavvy. Public domain via Pixabay.
Falling from trees
Living in trees, koalas sometimes fall from their perches. Normally they survive these spills and climb straight back up, but the inexperienced and young marsupials can suffer life-limiting injuries. A koala’s head has a higher proportion of cerebrospinal fluid, presumably to act as a shock absorber in case the animal falls.
Image: Koala by hb13thst. Public domain via Pixabay.
Koalas don’t have many natural predators. On the ground, they are most vulnerable since they are such slow movers. Here, they can be caught and ravaged by dingoes or even by large pythons. Joeys can be easy targets for larger birds of prey such as owls and eagles.
Image: Dingo by walesjacqueline. Public domain via Pixabay.
Featured image credit: ‘Koala Baby’ by Aaron Jacobs. CC BY-SA 2.0 via Flickr.