The koala (Phascolarctos cinereus), said also "small bear", is a marsupial mammal Australian, sole living representative of the family of the Fascolartidi or marsupial climbers. The scientific name drift from the Greek one (phaskolos, marsupial) and (arktos, bear) and from the Latin cinereus, grey.
The koala find themselves mainly along the coast eastern of the Australia, from Adelaide until the base of the Head Peninsula of York, and where is yourselves enough rain for support forests of eucalyptus, of whom the koala are greedy.
Fossils of koala I am rather rare, but some were found in Australia northern, risalenti to the Miocene. During this was, the northern half of the Australia was a tropical forest. You are they did not specialize themselves in a diet of eucalyptus until the climate did not allow a fall of the temperatures and the forests of eucalyptus continued to grow only in the tropical zones of forest. Some fossils experience that until 50,000 years does gigantic koala occupied the southern regions of the Australia.
The evolution of the species did not be of everything explained. It was hypothesized that the ancestor of the koala was a marsupial use to dig dens. The koala measures from 60 to 85 cm of length and has large ears rounded off and hairy, a gross makes one's will, lively eyes, wide muzzle and nude nose and crushed. It has a dirty gray fur of color: the superior part of the body is of ash grey color, the white belly yellowish, the hair is long, soft, woolly and, by means of the diet, smells of eucalyptus. The body is stocky and unprepared of tail the feet have five fingers prensili, with nails sharpened that itself on the trees allow to climb him, on which lives in small groups.
The koala goes almost all the life on the trees of eucalyptus. Of night it employs 4 hours to feed itself of about 500 grams of leaves and spends the remainder of the time dozing, wedged strongly in the bifurcation of a branch. Chance it go ashore for change tree or to favor the digestion swallowing land, cortex and sassolini.
It sleeps on the trees, generally in the points in which the branches branch off themselves. It pour evening, as arboreal nocturnal, the koala begin their composed meal of leaf and gems of eucalyptus, consumandone usually about means kg to the day. The mastication of the koala is extremely long, and the animal does not swallow the leaves and the gems before having reduced them to a thin pasta with the actual strong jaws.
The koala occupies an ecological niche quite precise, basing the actual nutrition on a type of vegetable them whose leaves are extremely carenti in proteins and fat, and rich of phenols and toxic terpeni to a lot of species. A such nutrition does not be able that to result in a very low metabolism also for a mammal: the koala, in fact, remains still for 18-19 hours to the day, big part of which passed sleeper.
To tolerate the leaves, the digestive system of the koala provides to deactivate the toxins thanks to a special liver and in this draw the more nourishment from the poor diet, also thanks to a stroke of the intestno the blind person, that in these animals is spacious inusualmente.
Actual to the eucalyptuses their characteristic balsamic perfume you are had to: having soaked some essential oils that find themselves on such trees, hinder to the parasites of to nest in the their soft hair.
Their common name drift from the word gula in lingea daruk an Australian dialect now extinguished, and means "that does not drink ever". The koala in fact need not to water itself, since the necessary water to their survival comes extracted from the leaves.
The coupling happens between December and March (southern summer), and the females bear an alone young animal, two in exceptions, since in the marsupial are alone yourselves two nipples. The varied gestation from 25 to 30 days. To the moment of the birth the small one weighs alone little grams and goes out from the lap to enter in the marsupial, that to difference of the other marsupial has the entry revolted towards the low, and where the newborn remains for about you are nutritious months itself alone of milk. In this make sentences they ears grow, eyes and hair. To about 30 months the nutrition comes integrated from a mixture of food predigerito, in the form of extremely liquid feci, that the small one takes on to develop an intestinal flora. The small become independent to about a year of age: before then, see the world from the shoulders of the mother, on that live seguendola wherever.
The koala reach the sexual maturity between the three and the four years, and the strongest male create themselves then a small harem.
The middle duration of the life of a koala is gone around on the vent' years. According to the iucn, the state of preservation of the koala today is at low risk of extinction. The koala of the Australia Southern had been exterminated during the first part of the XX century for their fur, but in the last 60 years the suspension of the hunting allowed a ripopolamento of the colony in the region, with coming families from the State of the Victoria. *Although the pleasant appearance and the docile behavior, the koala is not an animal from company. It is impossible to tame, and it has not confidence with the man. Moreover, in Australia detain a koala like domestic animal is illegal. The koala is one of the little mammals, on the other side of the supremacies, that is provided of finger prints. The finger prints of the koala I am surprisingly like to those humen, and the structure of the crests on the epidermis of the hands of the koala, also to the electric microscope, results substantially indistinguishable from that of the supremacies. It is discussed of an extraordinary and considerable example of evolution coincidentale.