All animals need water to live, but not all of them need to drink it from their surroundings. Drinking free water from rivers or puddles is just one of many ways that animals get the water they need. Until recently, koalas were thought to get most of their water from the leaves that they eat. But, after years of koala watchers getting caught in the rain, the scientists and volunteers (including Koala Clancy Foundation) began sharing similar, strange stories. These sleepy animals were waking up during storms and giving the tree bark a lively licking! Surprisingly, koalas appear to drink a type of free water rarely studied: stemflow. This is rainwater that drains down tree bark, and it is not just water. Stemflow picks up all types of things from the bark as it drains, from nutrients and pollutants to bacteria and fungi, raising many new questions for koala scientists.
by Dr Valentina Mella & Prof John Van Stan