Habitat loss and degradation remains one of the leading threats to wildlife around the world. And even when large tracts of land are left intact, habitats can be fragmented by the construction of roads, railways, and power-line right-of-ways. Animals that are unable to traverse these structures can become isolated and unable to find food or mates. However, other species (like Koalas) that are able to cross are forced to abandon their cover and become vulnerable to predation or incidents involving motor vehicles.
The potential for these issues to impact threatened wildlife populations was recently highlighted by a study led by Joerg Henning from the School of Veterinary Medicine at the University of Queensland. Noting that vehicle collisions were the primary cause of broken bones in Koalas admitted to veterinary hospitals, the group analyzed 13 years of data in order to determine the causes and prognoses of various fractures in injured Koalas.
The study’s disheartening results revealed that almost two-thirds of koalas were dead by the time they reached the veterinary hospital, and of those surviving, only around 2% were released back into native habitats. Vehicle collisions and dog attacks were the most common reasons for admission, and the studied injuries were most common during the breeding season, when individuals were actively seeking out mates. Because Koalas must eat almost constantly to glean enough energy from nutrient-poor Eucalyptus leaves, even relatively minor injuries can spell disaster.
The findings are especially alarming considering that an estimated 4000 Koalas are killed each year by cars and dogs alone, accounting for at least 4% of the current population. Koalas, once plentiful, have already suffered extreme decreases in populations size. In the 1920’s, there were approximately 10 million individuals, while today’s population is somewhere between 50,000 and 100,000, representing a 99% loss.At least 4000 Koalas are killed each year by cars and dogs alone. #nature #animals #climatechange Click To Tweet
The expansion of infrastructure is the Koala’s biggest threat, since the associated habitat loss and fragmentation increases their exposure to people, cars, and non-native predators. However, Koalas are increasingly affected by several recently acquired diseases, including a specific strain of Chlamydia and an HIV-like viral infection. Scientists and conservationists also believe that climate change is affecting the nutrient density of the animal’s primary food source Eucalyptus and that the change could eventually cause them to starve to death.
As bad as the situation is, the species has come a long way from its pitiful numbers in the early 30’s, and the declining populations are gaining the attention of both conservation groups and policy makers. One strategy being used to protect Koalas is the construction of tunnels and underpasses that allow safe passage underneath busy roads. As far as disease goes, conservation groups are doing their best to provide medical treatment to Koalas with Chlamydia, and culling efforts are also helping to limit the spread of infections.
However, the plight of Koalas is still very real, and some groups argue that the species will be extinct within the next decade. More research and conservation work will be needed to prevent further losses. Curbing carbon emissions and other aspects of climate change will also become increasingly important. To learn more or to support Koala conservation, consider visiting the Australian Koala Foundation website.