For many people, the iconic Australian is the cute and cuddly koala. Even their name is a little enigma because koalas are marsupials and not eutherian or placental mammals at all (more on that later)! Koalas are adorable and gentle creatures, but beyond their relatively simple visible traits, there is much more to learn. If you ever wanted to learn all about koalas and their daily challenges this is the article for you.
The World of Koalas:
As marsupials, koalas produce immature young that develop within a pouch. Koalas have specialized dietary requirements; their primary food source is eucalyptus leaves. These leaves are highly toxic, but koalas have an evolved digestion system to extract the required nutrients and detoxify at the same time.
A koala will spend most of its time in a tree and it’s rare that they descend to ground level. To climb and grip in the trees, the koala has sharp claws and large pads on its front and hind paws. Koalas like to sleep; they can doze for up to 22 hours per day to conserve energy. A diet of eucalyptus leaves may be relatively plentiful in some areas, but this food source has limited energy.
Because koalas are Australian marsupials they tend to be grouped together with other similar animals, including wombats, wallabies, Tasmanian devils, and kangaroos. In the marsupial order, koalas are classified as the sole extant members of the Phascolarcidae family.
Koalas are Australian native animals, and they can be found in Victoria, Queensland, South Australia, and New South Wales. They may inhabit various habitats in those states, but for obvious regions, they favour areas with eucalyptus trees. This could include woodlands, urban and rural areas, and coastal eucalypt forests. There is some slight variation with the species, koalas in the south tend to be larger and have thicker fur to deal with the colder winter conditions.
Anatomy and Physiology of the Koala:
There are seven distinct anatomical and physiological characteristics that set koalas apart from other Australian marsupials.
- Small Size: There is some slight variation, but most adult koalas weigh between 4-15 kg (9-13 lbs). They are considered to be small to medium-sized.
- Fluffy Ears: Koalas have large furry ears that are attuned to detect important sounds in their natural environment.
- Gray Fur: A koala is covered in soft fur that is usually gray, but there are brown-gray and silver-gray exceptions. This thick fur provides protection and insulation from the elements, and it’s thicker on southern koalas.
- Round Nose: A koala has a large and rounded nose that looks like a big black button that you feel compelled to “boop”. This nose is essential for find eucalyptus leaves that are ready to eat.
- Large Claws: The koala has large, clumsy, and sharp claws on its front and hind paws. They are well adapted to climb and grasp, with five distinct digits on each claw. In fact, two of these digits are opposed, and the second and third digits are joined together to form a larger “claw” used for grooming.
- The Pouch: A female koala has a pouch on her abdomen to protect and carry young koalas known as “joeys” as they develop.
- Facial Markings: Koalas have white patches around their eyes and along both sides of their noses. The markings are used to identify individuals, and it’s believed that they’re used for social recognition and communication.
Koala Behavior and Lifestyle:
Koalas are crepuscular, which means that they tend to be more active during dawn and dusk and they cannot be considered to be fully nocturnal. The patterns of koala activity are variable depending on certain factors, such as the habitat, temperature, and weather.
How Do Koalas Spend There Days
Most of the day is spent sleeping, and because they are usually spotted during the day, this has led to the incorrect assumption that they are nocturnal. During the early morning and late evening hours, the temperatures are cooler, and this is when koalas are more likely to feed. When the temperatures rise a koala will sleep or rest to avoid heat stress and conserve their energy for eating later.
Koalas are Usually Solitary;
They have a simple social structure, and an adult will have an exclusive territory that’s marked with a scent gland located on the chest. A territory may overlap with other individuals, and this is more common during the breeding season. Every koala has several trees that it considers to be home and these are regularly visited.
A koala is unlikely to visit another koala’s tree unless they are ready to breed and they are searching for a mate. The size of the home range of trees for each koala may vary depending on their age, sex, social position, and the habitat quality.
Are Koalas Territorial
A male koala tends to have a larger territory than a female and they will defend it with scent marking and vocal warnings. Female koala territories are smaller, and they often overlap with several males! Most typical interactions are brief, they may be friendly, but aggression is more likely when males compete for territory or mates. A male koala is ready to mate at 3-4 years old and females at 2 years old. She will give birth to a single joey annually for the next 10-15 years. A female koala has a gestation period of 35 days; she gives birth to one joey, but in rare cases, twins can be born.
The birth occurs between November – February and the joey stays in the pouch for the first 6 months. After the joey emerges, it will spend 6-12 months clinging onto its mother’s back. When the joey is 12 months old, it’s fully weaned and it will find a home range that overlaps with the mother’s territory for the first year. When the young koala is 2-3 years old, it will travel further afield to find a home. This typically occurs during the breeding season.
How Long Do Koalas Live For
A koala can live 10-12 years in the wild and a female can breed well into her teen years. Some female koalas live up to 18 years and males tend to have a slightly shorter lifespan. Throughout the weaning and rearing process the young joey is groomed, protected and taught how to be an adult koala. This is by far the most significant and longest lasting social interaction that will occur in the life of a koala.
Eucalyptus Diet and Feeding Habits of a Koala:
Learning all about koalas is impossible without understanding their relationship with eucalyptus trees. A koala can eat a variety of eucalyptus leaves. They can also consume related melaleuca, lophostemon, and corymbia tree species leaves, too, such as bloodwood, paperbark, and brush box. An adult koala can eat approximately 500g of tree leaves per day. They get most of their water from the leaves. A koala will only descend from the trees to drink water during hot and/or dry periods. The tree leaves are only 5% sugar and starch, which delivers very little energy, hence the koala lethargy.
A eucalyptus leaf contains similar toxic compounds to cyanide and most animals cannot eat them safely. Koalas share this food source with gliders and possums only, and this makes the leaves a relatively abundant albeit nutrient poor food source. Koalas can break down the toxic eucalyptus oils found in leaves with their digestive system.
The leaves are ground with the koalas’ ridged molars to extract the nutrients. The toxins are isolated by the koalas liver and then excreted in urine and faeces. The caecum is a coiled sac that branches from the large intestine. Any remaining nutrients are absorbed, and toxins are broken down here. The bacteria required for digestion is not present at birth. It’s passed to the joey by its mother in the form of “pap.” This is a sticky faecal material that’s ingested by the joey to get the bacteria it needs to digest leaves during adulthood.
Conservation Challenges to Save the Koala:
This distribution of the koala populations within Australia is determined by factors, such as food sources (eucalypt leaves primarily), habitat connectivity, and habitat availability. Certain populations are under threat from disease, habitat loss, and climate change. This has had an impact on survival and distribution. At the moment, the greatest threat is habitat loss caused by eucalypt diseases such as “dieback”, land clearance, and bush-fires.
FAQ’s-All About Koalas:
How do I Spot a Koala?
Koalas are hard to spot because they are typically wedged in a tree fork branch up in a tree. From a distance, they may look like a tree bump and their speckled gray coat can make them hard to see from ground level.
To find evidence of a koala, look at the ground for their small green-brown pencil-sized 20mm long fibrous droppings. If the pellets look fresh, it’s likely that the koala is sleeping, feeding, or lurking in the tree above. Another clue is the call that males make during the breeding season, which sounds like snoring! On a quiet night, this sound can be heard up to 1 km away, and a female may answer with a lower pitched bellow. If two koalas are getting frisky, you may hear wailing and squawking as they mate.
Are There Different Koala Types?
There is one recognized koala species (Phascolarctos cinereus), and within that species, there is some variation in size, appearance, and behaviour. Some experts have posited that these variations are koala subspecies, but this is not universally recognized.
Some of the proposed koala subspecies are the “New South Wales” koala (Phascolarctos cinereus victor), the “Queensland” koala (Phascolarctos cinereus cinereus), the “Victorian” koala (Phascolarctos cinereus adustus) and a koala known as (Phascolarctos cinereus cinereus) which resides in multiple regions. More study is required to determine how extensive these variations are and if they have any taxonomic relevance.
What is a Baby Koala Called?
They are known as “Joeys” or scientists may refer to them as “back young”, “pouch young” or “juveniles,” depending on their current level of development. When the joey is born, it’s approximately 2mm long, it’s furless, bling, and utterly helpless.
It travels to the pouch using touch and smell, and its newly formed limbs. When it enters the pouch, it finds one of a pair of teats (the second is for rare twins), and the teat swells to form a firm attachment. The joey will reside in the pouch for 6-7 months, living on its mother’s milk.
What is the Rarest Koala?
The proposed “Victorian” koala (Phascolarctos cinereus adustus) is getting harder to find. These koalas live in southern regions, such as parts of Victoria (hence the name) and South Australia.
How Can I Tell the Sex of an Adult Koala?
Males are larger; they have a larger black button nose and a broader face than females. Males have a scent gland in their chest, which may be visible if you’re up close and personal. An adult female has a back-facing pouch for their joeys and a clean white chest patch.
Can Koalas be Found in Varying Colors?
Yes, but these are typically limited to shades of gray, from brown-gray to silver-gray and shades in-between them. The age, genetics, environment and other factors can determine the color of an individual koala.
All About Koalas In Conclusion:
Now you know more about koalas, to learn all about koalas and join in conservation efforts you may need to take further steps. This Australian icon is under threat, and with a better understanding of their behaviors, biology, and habitat loss, we can help. To ensure that koalas have a future on this continent, we all need to take action.