Why Koalas Are Dying on the Ground
Although koalas normally live in trees, they are increasingly venturing to the ground — and dying there more often. But why?
According to a study, koalas spend less than one percent of their time on the ground.
This brief time can sometimes prove fatal.
Although they are in fact tree-dwellers, most koalas die on the ground. According to a recent study, the animals spend only 10 minutes a day there. How can this be? That is precisely what scientists in Australia, where koalas live, have been investigating.
Koalas live predominantly in trees, but due to large-scale land clearing they are increasingly forced to move along the ground, exposing them to a high risk of injury and death, explained study leader Gabriella Sparkes of the University of Queensland at a biology conference in Antwerp.
In the study, she examined the movements of koalas in detail by fitting the animals with GPS collars. The devices recorded their location at short intervals and were able to distinguish between walking, climbing and resting – thus enabling, according to the researchers, a level of fine-grained analysis previously unattained.
Koalas frequently die on the ground for a variety of reasons:
- Habitat loss: Due to urbanisation and deforestation, koalas lose their habitat, forcing them to set foot on the ground in search of new food sources.
- Traffic accidents: Many koalas are struck by vehicles when crossing roads. This is a common cause of death, particularly in areas where their habitats are fragmented.
- Disease: Koalas are susceptible to various diseases, such as chlamydia, which can severely impact their health. Sick koalas sometimes spend more time on the ground, making them more vulnerable to predators or further dangers.
- Predators: On the ground, koalas are more exposed to natural enemies such as dogs or other carnivores.
- Food scarcity: When food in the trees becomes scarce, they search for sustenance on the ground, which can place them in dangerous situations.
These factors together contribute to an increased mortality rate of koalas on the ground and place strain on the populations of this animal species, which are listed as “vulnerable” on the Red List of the International Union for Conservation of Nature (IUCN).
“If we can identify the tree species or habitat conditions that encourage koalas to remain in trees longer, we can design landscapes in ways that reduce the need for ground movement,” Sparkes is quoted as saying in a statement accompanying the presentation. As examples, she cited continuous canopy connections as well as shorter distances between suitable trees.
