Threats to koalas
Threats to Koalas
Loss of Habitat- the Single biggest threat.
Deforestation, urbanisation, bush fires and encroachment have diminished natural habitats for koalas to grow, thrive and reproduce. Removal of habitat is the single biggest threat to the koala population, as well as all other native wildlife in Australia.The vast majority of this loss of vegetation occurs as a result of urban development, agriculture, mining and the expansion of existing infrastructure.
An individual adult male coastal koala occupies up to 100 hectares; an area he occupies for life. Koalas live in a social hierarchy with higher-ranking animals occupying the best locations and lower-ranking koalas occupying lower quality habitats.
Due to habitat loss, the koala is now under threat, making it a sentinel animal for forest-dwelling species in this country. If the koala is wiped out, this will precipitate the demise of other fauna and flora. Australia holds the shameful title of having the greatest number of extinctions of mammals in the world.
Disease
Koalas in the wild face the threat of diseases (like chlamydiosis) that, without diagnosis and proper treatment, will quite often lead to death.
Chlamydia is a major disease threat to our Koala population. It is an obligate, intracellular bacteria that is found in many species of bird and mammals worldwide. Unfortunately, Koalas suffer from both bacterium species Chlamydia pneumonia and Chlamydia pecorum.
How does Chlamydia occur in Koalas?
What does it look like in Koalas?
If the koala is admitted to care in the early stages of ocular infection, there is usually an excellent chance of successful treatment.
How we help
When koalas are first admitted into the hospital, they undergo a full health screen examination. This is done under anaesthesia with the koala given a full physical assessment, blood tests are done and a PCR swab (Polymerase chain reaction which detects chlamydia cells) and finally an ultrasound to check the urogenital tract and other internal organs that may be affected by this disease. Urinary and reproductive tract infection is a much more complex scenario. Whilst the disease chlamydia does not favour either sex and will happily infect both male and female koalas alike, the female koala has “more plumbing” to deal with and therefore more complications can arise. Every time a koala becomes sick, more structural damage is done internally, no matter how well they may appear. Some koalas become infected for the first time and become so diseased, they deteriorate and die in a matter of weeks. Much of how koalas respond to this disease is driven by genetics, soil quality and soil moisture/nutritional status of trees, multiple pressures from disturbance of habitats, climatic conditions and how virulent the actual strain of the disease is in the area they live. If during this assessment the internal structural damage is so advanced, that the future quality of life for the koala is very poor then the kindest thing to do from an animal welfare perspective is to euthanase the koala whilst it is under anaesthesia. At the Koala Hospital (and across the country) relieving animals of severe pain is a major component of what we do.
What does treatment involve?
As a specialist folivore, koalas have evolved to cope with the toxic compounds found in eucalypt leaf by a number of mechanisms. Koalas have what is dubbed a “super liver” which is designed to break down and metabolise these toxins and eliminate them from the body. The koala also has a large gut system plus a two-metre caecum filled with a suite of micro-organisms (microbiome) all designed to break down the leaf allowing uptake of nutrients. This makes treatment difficult as antibiotics that are capable of killing the chlamydia in koalas also have the potential to kill off the important microbiome and as a result can kill the koala. There is a fine line between successful treatment and causing harm to the koala. Other medications such as non-steroidal anti-inflammatory drugs are metabolised and eliminated by the “super liver” before they are able to do the job they are designed to do. If the koala does not have disease that is too far advanced to be treated, then the koala will commence a 4-6 week treatment plan. At the end of the treatment plan, the koala is held for a further two weeks and “left alone”, then the koala is given a full health screen under anaesthesia again and if everything has been deemed “successful”, the koala is eartagged, microchipped and released back to its capture point. As the prevalence and severity of the disease is deeply related to Koala habitat, prevention is just as important as treatment. There needs to be far better management strategies and tighter more robust legislation put in place by both the Federal and State governments to ensure their protection well into the future. There needs to be large amounts of quality undisturbed forested environments free of humans set aside where koalas can live undisturbed to breed and remain healthy.
Injury and Attack
As a result of diminishing habitats, koalas face the frequent threat of injury or death from motor vehicles, as well as dog attacks.
Adult Koalas occupy a large home range in which they stay for their entire lives. The loss of parts of their habitat due to construction of roads, highways, shopping centres, housing estates and other human infrastructure have major implications for wild koala populations. Roads built within the koalas home range become obstacles over which Koalas must cross for the koala to find food, shelter and mates. This creates a great risk for the Koala to be hit be a moving vehicle as often they are hard to spot for the majority of motorists.
How to prevent dog attacks
- Choose a breed that is less likely to attack wildlife
Plant trees in the front of a yard (not near powerlines) in preference to backyards. - If koala trees are in a backyard – try to fence off where the tree or trees are to keep dogs away. Erect timber runners from the tree to the fence to allow the koala to not have to go down to the ground.
- Koalas often walk along the tops of fences to get from A to B. It is not unusual for a bigger dog to pull the koala off the fence and attack it. Try to house your dog in a fenced area that koalas will not visit.
- If possible lock dogs up at night.
- Always have your dog on lead when out on public land.
- Keep the Koala Hospital or other wildlife agency’s 24 hour emergency number handy and call immediately if your dog attacks a koala no matter what the time.
- Where possible wrap the koala up in a big blanket to keep warm while waiting for responders.
- Do not be fearful you will get “into trouble” – wildlife personnel simply wish to take the koala in for treatment.
