Perhaps one of Australia’s most iconic animals the Koala (Phascolarctos cinereus) is in trouble. Once being hunted heavily for their furs, their population was drastically reduced. The Koala is now listed as vulnerable under national environmental law.
Koalas are a living treasure, they are the only extant representative of the family Phascolarctidae meaning ‘pouched bear’ in Latin. Koalas are an arboreal herbivore meaning they spend most of their time in the tree tops eating leaves. In the case of the Koala they almost exclusively live and eat in eucalyptus trees.
This eucalypt diet has limited nutritional and caloric content and so koalas are largely sedentary, sleeping up to 20 hours a day. Being marsupials, koalas give birth to underdeveloped young that crawl into their mothers pouches where they stay for 6 months. They are truly unique animals.
Unfortunately, hundreds of koalas are turning up at animal hospitals clinging onto life with chronic stress. Chronic stress, particularly in urban and fringe zones, is creating very large barriers for conservation and recovery programs.
Biological stress happens after a stimulus causes the stress hormones adrenaline and cortisol to be realised into the body. These changes affect the basic functioning of the immune system, reproduction and growth. Chronic stress over a long time can seriously affect survival rates.
The most common sources of stress for koalas are heat stress, car impacts and dog attacks. Each year, hundreds of koalas are taken to veterinary clinics after being rescued from roadsides or beneath trees, and the incidences increase during the summer months.
Human population growth, road expansion and extensive land clearance have fragmented their eucalyptus habitat and reduced the ability of koalas to move across the tree canopy; making the species most vulnerable on the ground. Only 20% of their original eucalyptus home is left for them to use. Some of what is left is unfortunately on private land meaning the owners can do what they want with their land.
Maternal stress, nutritional deprivation, dehydration and possible accumulation of oxalate in eucalyptus leaf increase during drought periods. Foetal development of koalas could also be impacted by maternal stress due to lack of adequate food from gum trees in drought periods. These periods of drought are being seen more often due to global climate change.
There are many experts that believe the koala will become extinct within the next 30 years if efforts aren’t taken to protect them now. This is a very grim outlook for such an iconic animal, and so positive changes need to be implemented fast.
Conservation efforts heavily fall in the effort of trying to protect habitat where the animals live. Work needs to be put into place to better inter connect these habitat patches. If the koalas cannot move around then it is easy for a wild fire to wipe out an entire population within days.
It would be a shame if Australia cannot save one of its most famous creatures. Attitudes need to be changed in order for people to realise koalas need help. Humans have caused such stress for koalas and it is only humans who can help to save this amazing animal.