The primary diet of koalas consists mainly of eucalyptus leaves. Koalas are herbivores and have adapted to consume the leaves of specific eucalyptus tree species, which provide their essential nutrients. Due to the fibrous and challenging nature of eucalyptus leaves, koalas have specialized adaptations, including a slow metabolism and a highly developed digestive system, which allows them to extract nutrients from these leaves effectively. Koalas are selective feeders, choosing leaves based on factors like moisture content and toxicity, which enables them to thrive in their natural habitats.