#10 is so bizarre!#10 is so bizarre!
There are so many cute Australian animals and the koala is definitely one of them. Get to know more about this furry, cuddly, and unique animal from the land down under.
Koalas are unique to Australia
This adorable tree-hugger can be found in the forests of eastern and southeastern Australia. They are arboreal, meaning they live on trees. Eucalyptus trees are their preferred homes which are also their source of food.
Koalas living in the north are quite different from southerners. They are smaller, lighter in colour, and have less fur compared to their southern counterpart.
Koalas are not bears
When they were first discovered, koalas were mistaken as bears because of how they look, hence the misnomer koala bear. Even its scientific name Phascolarctos cinereus got it somewhat wrong as it loosely translates into ash-grey(cinereus) pouched(phaskolos) bear(arktos).
Scientists later realised that koalas belong to another group of animals-- the marsupials. They are a type of mammal that gives birth to an underdeveloped young which they carry in their pouch. Kangaroos, wombats, possums are some other examples of marsupials.
Koalas have unique pouches
Some marsupials like kangaroos and possums have pouches that open upward while others like wombats and quolls have pouches that open to the rear.
Koalas have neither. Their pouches are located on the bottom part of their bellies, but they open outward not to the rear. To keep their baby joeys from falling out, the mother koala uses the strong sphincter muscles on its pouch to keep it closed.
Koalas have a special diet and are fussy eaters
Koalas eat eucalyptus leaves which are poisonous to every other animal except the ringtail possum and the greater glider which are also native Australian animals.
Despite the toxins in eucalyptus leaves, koalas can eat around 500 grams of leaves per day. That said, they are picky when it comes to their food. Out of the 700 eucalypt species, only about 50 species make it to a koala’s preferred diet. Since not all eucalypt species are present in a particular habitat, a koala may only have a few choices depending on where it lives.
Even if a particular tree is one of the preferred species, koalas don’t just eat any leaves that grow from it. They sniff on the leaves before deciding if they are good for eating.
Koalas have a specialised caecum for digesting the fibrous eucalyptus leaves. Other animals also have this organ but a koala’s caecum is very long compared to other animals. This allows the food to stay there for longer where it can be broken down by a lot of bacteria contained therein before being absorbed by the body. The liver also helps in filtering out toxins so that they will not harm the koala.
Koalas are well-adapted to their environment
Koalas have a lean muscular body as well as long strong limbs well suited for climbing trees. Their paws are adapted for gripping on tree trunks and branches. They have rough pads on their palms and soles. Their forepaws have two opposable digits and they have long sharp claws to help them grip more securely.
The base of a koala’s spine has cartilaginous pads, and its bottoms are covered with extra fur. So sitting on their butts on tree branches for a very long time is no problem at all. Also, the koala’s spine is curved which makes its body fit well in between tree wedges.
The thick, woolly fur of koalas protect them from temperature extremes in their habitat. The fur also acts as a “raincoat” as it can repel moisture. Koalas living in southern parts of Australia have thicker fur which is likely an adaptation to the colder winters in the south.
Koalas have a large nose and a keen sense of smell. Scientists surmise that this characteristic helps them detect the level of toxicity of eucalyptus leaves so they can choose only the least toxic ones. Furthermore, scientists have learned that koalas have taste receptors that can determine the leaves’ nutritional value and water content. This helps the koalas get the most of what they eat considering that eucalyptus leaves provide very limited nutrition.
Koalas are solitary and tend to live apart in their habitat. When it is time to socialise with their kind like if they are looking for a mate, their large ears and their great sense of hearing help them a lot.
Koalas spend most of their time sleeping
Koalas can sleep for up to 20 hours a day. They are not exactly lazy. It is just that their diet provides them with very little nutrition and energy. Digesting tough eucalyptus leaves also takes a lot of energy. So sleeping is just the best way to deal with this situation.
So what do they do when they are not sleeping? They spend most of their waking hours eating.
Koalas rarely drink water
Koalas get their water requirements through the leaves they eat. They will occasionally take a sip of water in times of drought and when the eucalypt leaves have lower water content than usual. The name koala is thought to mean “no drink” in the aboriginal language.
Adult male koalas are larger than adult female koalas
Northern adult male koalas have an average length of 70.5 centimetres and an average weight of 6.5 kilograms. While the adult females have an average length of 68.7 cm and weigh 5.1 kilograms on the average.
Southern adult male koalas have an average length of 78.2 cm and have an average weight of 12 kilograms. The adult female on the other hand measures around 71.6 cm on the average and weighs around 8.5 kilograms.
Aside from the difference in size, the males also have a noticeable scent gland on their chest while the females have a plain white chest.
Newborn koalas are very tiny
Being a marsupial, koalas give birth to relatively underdeveloped young. A newborn koala is just around two centimetres long and weighs less than one gram. They are born blind, with undeveloped ears, and hairless. Like other newborn marsupials, they look like a pink jelly bean.
The baby koalas, also known as joeys will climb into their mothers’ pouch and continue their development there. They will stay in the pouch for around five months, feeding solely on their mothers’ milk.
Young koalas have a weird diet
At around six months, the joeys will now have fur, can open their eyes, and have developed ears. They are ready to feed on pap--a special meal just for koala joeys. Pap is a specialised type of poop! But instead of the usual hard and dry koala poop pellets, this one is soft and runny.
This substance provides the needed bacteria for the joeys’ gut so that they too will be able to process eucalyptus leaves later. It is also loaded with protein to help with the joeys’ development. This pap feeding will go on for around two months. Afterwhich, the joey can eventually munch on eucalyptus leaves.