The Koala is a marsupial
The Koala ( phascolarctos cinereus ) is an arborical ( corner populate ), herbivorous ( plant eating ) marsupial. The news ‘ marsupial ’ comes from the Latin parole marsupium, meaning ‘ pouch ’. Most, but not all, female marsupials have a permanent wave pouch in which to raise their unseasoned .
When Europeans beginning came to Australia they thought that Koalas were bears, so they were frequently called ‘ Koala bears ’. not much was known about marsupials at the time of colonization and it ’ s possible that no European had seen a marsupial prior to that .
Some early settlers besides referred to Koalas as ‘ monkeys ’ and some people even call one of the favor Koala food trees in the south of Australia ‘ Monkey Gums ’. however, in an effort to educate people that Koalas are marsupials, we discourage people from using these wrong names, specially ‘ Koala wear ’, which is in fairly common custom. The adjust term is plainly ‘ Koala ’.
Adaptations for a life in the trees
The Koala is well suited to its life in the trees. Unlike other arboreal marsupials such as the tree kangaroo, the Koala does not have an external tail. however vestiges of a fag end are still present in the skeletal structure of the Koala, indicating that at some time in its evolutionary history an external tail was deliver. It shares this feature with the wombat .
Above: The Koala ’ s closest relative is the common wombat .
Despite having no tail, the Koala has an excellent sense of balance. With a list, muscular torso, and relatively long, strong limbs, the Koala can support its weight when climbing. The front and hind limbs are closely equal in length and much of the Koala ’ s climbing lastingness comes from the second joint muscleman, which joins the shin much lower than in many other mammals .
The Koala ’ south paws are particularly adapted for gripping and climbing. Rough pad on the palms and soles help it to grip corner trunks and branches, and both front and back paws have long sharp claw. Each paw has five digits ; on the front paw, two digits are opposed to the early three–rather like a human ’ randomness thumb–so they are both able to be moved in opposition to the other three. This allows the Koala to grip more securely. distinctive latitude Koala scratch marks on tree trunks are due to this particular characteristic .
On the back paw, there is no claw on the biggest digit, which is opposable to the others for gripping. The second and third base digits are fused together to form a double-clawed finger which is used for grooming purposes, such as for removing ticks .
Above Left: Front Paws. photograph : Dick Marks
Above Right: Hind Paw. photograph : Phillip Wright .
The Koala’s fur – a protective “raincoat”
Koalas have thick, flocculent fur which protects them from the extremes of both high and low temperatures, and which besides acts like a ‘ raincoat ’ to repel moisture when it rains. The fur varies in tinge from fall grey to brown. Koalas in the south by and large tend to have fur which is colored and thick ( and sometimes brown ) than those in the north. These variations are gradual changes from north to south, and there are some differences of impression amongst scientists as to whether the variations mean that there are separate sub-species of the koala .
Koalas have patches of egg white fur inside the ears, on their chin, chest of drawers and neck, inside the front limbs and sometimes on the back of the back limb, and normally in patches on their hindquarters. Mature males are recognizable by the brown university scent gland in the center of their chest which they rub on the tree trunks to deter other Koalas, particularly early males, from entering their home trees .
The fur on the Koala ’ sulfur rump is dumbly packed and provides an built-in ‘ shock absorber ’ for the heavily branches it sits on. The rump ’ s white stipple appearance makes Koalas hard to spot from the ground .
How big are Koalas?
Koalas in the confederacy of Australia are well larger and have thick, much browner fur than those in the union. These are likely to be adaptations to the cold winters in the south of the nation.
|Southern Koalas||Northern Koalas|
Length: 75-82cm (Average: 78.2cm)
Weight: 9.5-14.9kg (Average: 12kg)
Length: 67.4-73.6cm (Average: 70.5cm)
Weight: 4.2-9.1kg (Average: 6.5kg)
Length: 68-73cm (Average: 71.6cm)
Weight: 7-11kg (Average: 8.5kg)
Length: 64.8-72.3cm (Average: 68.7cm)
Weight: 4.1-7.3kg (Average: 5.1kg)
|Note: 1Kg = 2.2lb, and 2.54cm = 1 inch|
A comparatively small brain size
Although the Koala ’ sulfur head is large in proportion to its body, its brain is smaller in comparison to early closely-related marsupials ( in sexual intercourse to their size ), and has less come on fold and larger hollows within the brain. It ’ mho been suggested that a smaller mind uses less energy and that this could be an adaptation to allow the Koala to survive on its depleted energy diet .
Highly developed hearing and sense of smell
The Koala ’ s unusually big, coriaceous nose is one of its most detectable features. Koalas trust on their highly developed smell of smell to differentiate levels of toxins in eucalyptus leaves, to detect the levels of toxicity in the leaves at any finical time. They besides need to smell the odorize warnings put on trees by other Koalas. It ’ mho think that the Koala ’ s cutting sense of smell is already good developed at birth, leading the blind and young neonate joey to the bulge through the olfactory property of the mother ’ randomness milk from the teats in the pouch .
Koalas ’ large ears provide a bang-up sense of learn, which is necessary for their socialization with other Koalas, as they can live in populations where each Koala lives big distances apart. photograph : Christiane Scheffler
Koalas ’ eyes are relatively little in relation to the size of their other sensory features, such as their ears and intrude. Their eyesight is not peculiarly highly developed .
The differences between male and female Koalas
Adult male Koalas are larger than adult females, who have a pouch in the concentrate of their abdomen with the possibility more towards the bottom of the pouch than the crown. The external genitalia are visible on a male Koala .
One of the easiest ways to identify the sex of a Koala is to look for the dark brown university scent gland which is located in the centre of the egg white chests of ripe, breeding males. Females and youthful pre-breeding males have a plain white thorax. The male Koala is much referred to as a ‘ buck ’ and the female as a ‘ department of energy ’ .
Right: Mature male showing sternal perfume gland. photograph : Phillip Wright .
Female Koalas have been described as having a ‘ backward-opening ’ pouch like wombats, as opposed to an upward-opening pouch like kangaroo. however, that ’ s not rigorously true. When a female Koala first gives birth to young her pouch open faces neither up nor down, although it is located towards the bed of the pouch quite than at the clear. It faces straight outwards rather than ‘ backwards ’ .
It sometimes appears to be ‘ backward-facing ’ because when the joey is older and leans out of the pouch, this pulls the bulge downwards or ‘ backwards ’. The pouch has a potent sphincter muscle at the open to prevent the joey from falling out .
Left: The Koala ’ s pouch appears to be ‘ backward-opening ’ when the older joey puts its principal out. The opening is towards the bottom of the bulge rather than at the top. photograph by Wendy Blanshard
Koala body temperature
The Koala ’ s body temperature is systematically lower than most mammals, at 36.6 degrees C, and they have a gloomy metabolic rate.
Koala heart rate
The resting center rate of a Koala is anywhere between 70-140 beats per moment ( it will depend on a range of factors, including the senesce of the Koala ). It can be unmanageable to measure a perch heart rate for a Koala as they have a ‘ venous sinus cardiac arrhythmia ’ which means that their heart rate and breathing get out of synchronize. This can cause fluctuations in the heart rate which aren ’ thyroxine a reflection of the actual heart rate–resting or active .
Koalas are the only other animal that have individual fingerprints like humans. A scientific analyze compared homo and Koala fingerprints, finding that the Koalas ’ are easily distinguishable from humans ’, but there are some similarities. It was noted that each Koala has a unlike fingerprint from other Koalas .
Koala rib cage
It ’ s a misconception that Koalas don ’ t have a rib cage and that is why they don ’ thyroxine like to be picked up. Of course, they do have a rib cage to protect their inner organs. however, while many mammals–most marsupials and primates like us–have 13 pectoral vertebra and therefore 13 pairs of rib, Koalas have lone 11 pairs ; the least of any record marsupial species. They have a curved spine and a cartilaginous pad over the end of the spinal column which may make it more comfortable to sit on branches and in tree forks. Koalas are sensible around their abdominal area and need something to grip onto when being picked up. A Koala should not be picked up under its arms like a toddler because it ’ s accustomed to gripping onto branches with its front paw, and it will feel uncomfortable and vulnerable .