Koala Teeth: Everything You Need to Know

If you are under the impression that koalas are bears just because they look like small bear cubs, then you are wrong. Koalas are actually marsupials mainly settling in eucalypt forests in Australia. 

Koalas conserve a lot of energy from a lot of sleeping. In fact, they are one of the rare animals on the planet who spend the vast majority of time sleeping. During the day, koalas can sleep or relax for up to 22 hours, which is necessary since their bodies require a great deal of energy to absorb food, and sleeping allows them to conserve energy.

Koalas survive on a diet of eucalyptus leaves, and they are in fact, the only species of mammals, other than the greater glider and ringtail possum, which can thrive on a diet like this. It might be surprising, but eucalyptus leaves lack essential nutrients and are exceedingly fibrous, not to mention that to most mammals, they are also dangerous. Koalas, however, are gifted with specialized digestive systems to cope with their diet. That being said, it is hard not to be curious how these little marsupials chew their favorite leaves! Below, we’ll explore everything you need to know about koalas’ teeth.

What Kind of Teeth Do Koalas Have?

The koala’s teeth have a gap in between the incisors and premolars, called a diastema, where the eucalyptus leaves are kept before the cheek teeth process them. 

The koala’s teeth are tailored to their herbivorous diet, and it is somehow akin to those of a wombat or a kangaroo, which are both marsupials like them. 

Koala teeth are specifically adapted to their gum leaf diet, which they consume in really large quantities. An adult koala consumes between 200 and 500 grams of eucalyptus leaves each day, depending on its size. The leaves of the eucalyptus tree are nipped from the tree by their sharp front teeth, and their back teeth are constructed specifically for slicing and crushing the leaves in order for the koalas to extract the maximum amount of nutrition.

Are Koala Teeth Sharp?

The koala’s front teeth or incisors are sharp and can snip leaves, while their cheek teeth are meant to crush their food before swallowing. However, they are not sharp enough to pierce through meat or cut prey.

The presence of a ‘diastema’ or gap between their incisors and molars enables their tongue to properly navigate the volume of leaves throughout the mouth. Koalas also love to store food within their cheeks during their 18 to 22-hour long sleep so they can chew on them and eat them in the middle of their nap.

How Many Teeth Do Koalas Have?

As marsupials, the number of teeth in a koala’s mouth do not vary greatly to many primates and other mammals. Koalas have about 30 teeth. The dental formula for koalas is as follows: Incisors 3/1, Canines 1/0, Premolars 1/1, Molars 4/4 = 30. The formula shows how many teeth are on the top and bottom of one side of the jaws, which is represented by “top/bottom.” 

Koalas are diprotodont, like the other members of the marsupial group Diprotodontia that includes wombats, kangaroos, and phalangers. As a diprotodont, koalas have less than three upper incisor teeth on each side of their jaw.

What Do Koalas Eat?

As herbivores, koalas only eat a diet that includes pure plant materials. Koalas are well-known to munch on eucalyptus leaves, which can be very poisonous to many other animals. However, koalas have their own unique digestive system that helps them digest and adapt to this kind of diet.

Koalas can also eat some other leaves that are not Eucalypt species found within their habitat, such as Brush Box and Melaleuca.

Are Eucalyptus Leaves Poisonous for Koalas?

The Koala’s digestive tract is very good at getting rid of the poisonous chemicals in the eucalyptus leaves. Scientists believe that these toxins emitted by eucalyptus leaves are made to protect them from herbivores like bugs. However, it is also believed that eucalyptus trees that grow in poor soil are more poisonous than those growing in fertilized soils. Which is also why koalas only eat some types of eucalyptus leaves and not all of them. In Australia alone, there are approximately 600 eucalyptus types, but koalas won’t even touch the majority of them. In fact, they might eat only 40 to 50 of those.

Inside a koala’s digestive system is a unique organ that digests fiber called the caecum. Eucalyptus leaves are very fibrous, and caecum has a plethora of bacteria that help break the fiber down into more absorbable and digestible materials. Despite the help of caecum in breaking all of the fiber down, the Koala can only take in 25% of the fiber it eats, so what they do is sleep most of the day to save energy which in turn will be used to digest the gum leaves.

Do Koalas Teeth Wear Out?

Scientists have long associated koalas’ tooth wear to their life span or as to how much time they have left to live. A 2002 study published in the Australian Journal of Zoology suggests that tooth wear in koalas is generally a result of their continuous chewing and grinding of eucalyptus leaves. Koalas, apparently, more often die of starvation than of old age, as the more of their teeth wear down, the less gum leaves they eat and digest.

Do Koalas Bite Humans?

There are rare occurrences where koalas bite humans, with the exception of wildlife professionals and those who work with koalas on a regular basis. Koalas usually do not bite humans, but might, if they believe they are being threatened or when they are terrified. Koalas like to stay by themselves in the bushland, so you shouldn’t be concerned about being bitten or attacked. Their teeth should not be your first concern too, as koalas have sharper razor-like claws that can cause serious injuries.

The photo featured at the top of this post is © iStock.com/obtokyoharris