What Do Koalas Eat?

Koalas are arboreal marsupials native to southern and eastern Australia. Despite its common name, the koala bear is not a bear at all, and its closest living relative is the wombat. The sole member of the family Phascolarctidae, the average koala measures 24 to 33 inches long and weighs from 9 to 33 pounds. Known for their distinctive round head and fluffy greyish-brown fur, koalas have become a symbol of conservation in Australia. While they have few natural predators, the IUCN lists the species as Vulnerable due to habitat loss. Today, conservation efforts are in place that aim to stabilize and increase the number of koalas. Part of the problem is that koalas eat a very specific, low-nutrition diet. This makes conservation more difficult, as it means that only certain habitats are suitable to sustain koala populations. We must therefore ask the question, “what do koalas eat?”

In this article, we’ll make an effort to fully flesh out the diet of koalas. We’ll begin by talking about what koalas like to eat. Next, we’ll discuss how koalas go about foraging for food. Then, we’ll compare what they eat in the wild versus what they eat in captivity. Finally, we’ll end with a conversation about what baby koalas eat. So, without further ado, let’s answer the question, “what do koalas eat?”

What Do Koalas Like to Eat?

Koalas are arboreal herbivores, meaning that they spend most of their lives in trees and eat plant matter. To be precise, the bulk of a koala’s diet consists of a single food, the leaves of the eucalyptus tree. There exist over 600 species of eucalyptus, but koalas tend to show a strong preference for the leaves of certain trees. Additionally, as different eucalyptus trees grow in different regions, the diet of a koala in one place will differ from that of a koala in another region. That said, koalas will spend time in other trees and eat the foliage of other tree species. For example, some other trees that koalas forage on include brush box, paperbark, and bloodwood trees. Still, eucalyptus leaves are by far the most important part of a koala’s diet. Similar to how the giant panda relies mostly on bamboo, koala populations could not survive with eucalyptus. 

How Do Koalas Forage For Food?

Koalas have adapted specific senses to help them find food while foraging in trees. Namely, koalas mostly rely on their sense of smell to help them find trees that they like to eat. Their keen nose helps them to determine which eucalyptus trees they like, and which to avoid. On the other hand, koalas possess poor vision, and so only marginally rely on their eyesight to find food. Additionally, while they have amazing hearing, their hearing is not so useful in locating their next meal. Rather, their hearing is useful for detecting predators and communicating with other koalas. Koalas also have a sensitive sense of touch, as they use their hands to navigate trees and handle food. Finally, koalas also have a unique sense of taste, as they evolved more bitter taste receptors than other marsupials. This likely allows them to detect toxic substances in eucalyptus leaves. 

Given that eucalyptus leaves possess poor nutritional content, koalas spend a large part of their day sleeping. On average, a koala will sleep between 18 and 22 hours each day to save energy. Additionally, eucalyptus leaves are poisonous to most animals, but koalas have evolved to process the toxins in the leaves. That said, even koalas will avoid the leaves of certain trees that possess high levels of toxins. Koalas evolved an organ known as a caecum, which is full of bacteria that help to break down the fiber in eucalyptus leaves. On average, a koala will eat between 1 to 1.5 pounds of leaves per day. Koalas use their sharp incisors to rip the leaves, and then their molars to cut and shear them. They feed by holding onto a branch with their back paws while feeding with their front paws. 

What Do Koalas Eat in the Wild?

In the wild, koalas spend the majority of their day eating and sleeping, particularly sleeping. Although they sleep on average 20 hours per day, koalas still manage to feed between 5 to 6 times per day. This is necessary, given the low nutritional content of their diet, which is almost exclusively made up of eucalyptus leaves. Additionally, although there are more than 600 types of eucalyptus trees, koalas strongly prefer a few over most of the others. Research suggests this has to do with lower toxins and fiber content and higher protein content in the leaves of these trees. While the majority of their diet consists of eucalyptus leaves, koalas also occasionally dine on the leaves of other trees. Some of their other favorites include the leaves of brush box trees, paperbark trees, and bloodwood trees. They appear to frequently enjoy eating these leaves on hotter, drier days. 

What Do Captive Koalas Eat?

Due to their cute appearance, koalas are common in both the exotic pet trade and in zoos around the world. Despite their cuddly look, koalas don’t make great pets and require a lot of specialized care. This care starts with their diet, which is very specific. In captivity, koalas are often fed branches from several different types of eucalyptus tree each day. This ensures that they get plenty of variety in their diet. Also, because koalas are notoriously picky, it makes it more likely that they will get enough nutrition. Upon being presented with a selection of branches, a koala will then set about choosing its favorite leaves. Somehow, koalas always seem to know which plants to avoid ingesting too many toxins. A captive koala can eat between 1 to 1.5 pounds of leaves in a single day 

What Do Baby Koalas Eat?

Like other marsupials, koalas give birth to underdeveloped young. After a 33 to 35 day gestation period, a female koala will give birth to a sole joey, or baby koala. The average joey weighs around 0.02 ounces, and is completely reliant on its mother. Upon birth, the joey will then crawl into its mother’s pouch, where it will remain for the first 6 or 7 months of its life. Inside the pouch, the joey lives off of its mother’s milk. However, female koalas produce relatively very little milk. To compensate, the joey will drink its mother’s milk for the first year of its life. At around 6 months old, the female koala will begin to prepare her offspring for a eucalyptus-based diet. To accomplish this, the female will eat leaves, predigest them, and then produce a fecal pap to feed to her joey. 

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