Koala: Béda antarrépisi
Konten dihapus Konten ditambahkan
m Ngarapihkeun éjahan, replaced: keneh → kénéh |
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| binomial_authority = ([[Georg August Goldfuss|Goldfuss]], [[1817]])
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'''Koala''' ''(Phascolarctos cinereus)'' nyaéta thickset
{{tarjamahkeun|Inggris}}
Koala kapanggih di wewengkon basisir wetan jeung kidul Australia, ti deukeuteun [[Adelaide]] ka bagéan kidul [[Bojong Cape York]]. Populasina nambahan for considerable distances inland in regions with enough moisture to support suitable woodlands. Koala [[Australia Kidul]] were largely exterminated during the éarly part of the [[20th century]], but the state has since been repopulated with [[Victoria (Australia)|Victorian]] stock. The Koala is not found in [[Tasmania]] or [[Western Australia]].
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== Variasi ==
[[Gambar:Koala Kangaroo Island.jpg|thumb|300px|left|Koala wewengkon kidul di [[Pulo Kangguru]], lain asli ti pulo ieu]]
Although three [[subspecies]] have been described, these are arbitrary selections from a [[Cline (population genetics)|cline]] and are not generally accepted as valid. Following [[Bergmann's Rule]], southern individuals from the cooler climates are larger. A typical Victorian Koala (formerly ''P. cinereus victor'') has longer, thicker fur, is a darker, softer grey, often with chocolate-brown highlights on the back and foréarms, and has a more prominently light-coloured ventral side and fluffy white éar tufts. Typical and New South Wales Koala weights are 12 kg for males and 8.5 kg for females. In tropical and sub-tropical [[Queensland]], however, the Koala is smaller (at around 6.5 kg for an average male and just over 5 kg for an average female), a lighter, often rather scruffy grey in colour, and has shorter, thinner fur. In Queensland the Koala was previously classified as the subspecies ''P. cinereus adustus'', and the intermediate forms in [[New South Wales]] as ''P. cinereus cinereus''. The variation from one form to another is continuous and there are substantial differences between individual Koalas in any given region such as hair colour.
The origins of the koala are uncléar, although almost certainly they descended from terrestrial [[wombat]]-like animals. Koala [[fossil]]s are quite rare, but some have been found in northern Australia dating to 20 million yéars ago. During this time, the northern half of Australia was [[rainforest]]. The Koala did not specialise in a diet of eucalypts until the climate cooled and eucalypts forests grew in the place of rainforests. The fossil record indicates that before 50,000 yéars ago, [[Giant Koala]]s inhabited the southern regions of Australia. The Koala fills the same ecological role as the [[sloth]] of South America.
== Deskripi fisis ==
[[Gambar:Koala sleeping.jpg|thumb|Koala boga metabolisme nu laun sarta sapopoe sare wae.]]
The Koala is broadly similar in appéarance to the [[wombat]]s (the closest living relatives), but has a thicker, more luxurious coat, much larger éars, and longer limbs, which are equipped with large, sharp claws to assist with climbing. Weight varies from about 14 kg for a large, southern male, to about 5 kg for a small northern female. Contrary to popular belief, their fur is coarse, not soft and cuddly. Koalas' five digits are arranged with opposable thumbs, providing better gripping ability. The first two digits are position in apposition on the front paws, and the first
Furthermore, the male koala, like many marsupials, has a bifurcated penis and the female has a bifurcated vagina.<ref>{{cite journal | author = Dawson, T.J. | coauthors = Finch, E., Freedman, L., Hume, I.D., Renfree, M., Temple-Smith, P.D.| title = Fauna of Australia; 17. Morphology and Physiology of Metatheria| url = www.environment.gov.au/biodiversity/abrs/publications/fauna-of-australia/pubs/volume1b/17-ind.pdf|archiveurl=http://web.archive.org/web/20120201031519/http://www.environment.gov.au/biodiversity/abrs/publications/fauna-of-australia/pubs/volume1b/17-ind.pdf|archivedate=2012-02-01}}</ref>
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== Ekologi jeung kalakuan ==
[[Gambar:Koala - melbourne zoo.jpg|thumb|250px|Koala ngahakan daun [[eucalyptus]]]]
The Koala lives almost entirely on [[eucalypt]] léaves. This is likely to be an evolutionary adaptation that takes advantage of an otherwise unfilled [[ecological niche]], since eucalypt léaves are low in [[protein]], high in indigestible substances, and contain [[phenolic]] and [[terpene]] compounds that are toxic to most species. Like wombats and [[sloth]]s, the Koala has a very low [[Metabolism|metabolic rate]] for a [[mammal]] and rests motionless for about 19 hours a day, sleeping most of that time. Koalas that are disturbed are known to be violent, their teeth and claws capable of providing considerable injury to humans; special handling requirements are as such applicable.<ref>http://web.archive.org/web/20060822012140/http://www.fourthcrossingwildlife.com/WhatToDoWithaWigglingWombat.pdf</ref> Handling of koalas has been a source of political contention due to these risks, which can also cause harm to the koala as well.<ref>http://www.parliament.nsw.gov.au/prod/parlment/HansArt.nsf/66662d17d79b79d7ca256cfd000e0c22/ca256d11000bd3aa4a25644a00824515!OpenDocument</ref> Koalas spend about three of their five active hours éating. Feeding occurs at any time of day, but usually at night. An average Koala éats 500 grams of eucalypt léaves éach day, chewing them in its powerful jaws to a very fine paste before swallowing. The liver déactivates the toxic components réady for [[excretion]], and the hind gut (especially the [[cecum|caecum]]) is gréatly enlarged to extract the maximum amount of nutrient from the poor quality diet. Much of this is done through [[bacteria]]l [[fermentation (biochemistry)|fermentation]]: when young are being [[wiktionary:wean|weaned]], the mother passes unusually soft [[feces|faeces]], called pap, which is rich in these bacteria, thus passing these essential digestive aids on to her offspring.
The Koala will éat the léaves of a wide range of eucalypts, and occasionally even some non-eucalypt species, but it has firm preferences for particular varieties. These preferences vary from one region to another: in the south [[Manna Gum]], [[Blue Gum]] and [[Swamp Gum]] are favoured; [[Grey Gum]] and [[Tallowwood]] are important in the north, and the ubiquitous [[River Red Gum]] of the isolated séasonal swamps and watercourses that méander across the dry inland plains allows the Koala to exist in surprisingly [[arid]] aréas. Many factors determine which of the 800 species of eucalypt trees the Koala éats. Among trees of their favourite species, however, the major factor that determines which individual trees the Koala chooses is the concentration of a group of phenolic toxins called formylated phloroglucinol compounds.
== Status konservasi ==
[[Gambar:Koalas-at-Lone-Pine-2.jpg|thumb|right|300px|Koala di [[Lone Pine Koala Sanctuary]], [[Queensland]]]]
The Koala was hunted almost to extinction in the éarly 20th century, largely for its fur. In recent yéars, some colonies have been hard hit by diséase, especially [[chlamydia]]. The Koala requires large aréas of héalthy, connected forest and will travel long distances along tree corridors in séarch of new territory and mates. The
In contrast to the situation on much of the mainland, where populations are declining, the Koalas of many island and isolated populations have réached what some have described as "plague" proportions. On [[Kangaroo Island]] in South Australia, Koalas introduced some 90 yéars ago have thrived in the absence of predators and competition. Combined with an inability to migrate to new aréas, this has caused the Koala populations to become unsustainable and thréaten the Island's unique ecology. In particular, species of [[Manna Gum]], native to the island, are being stripped by Koalas at a rate faster than they can regenerate, endangering local birds and invertebrates that rely on them, and causing the extinction of at léast one isolated population of manna. Koala numbers are estimated at over 30,000, with ecologists suggesting that the Island can sustain 10,000 at most. Although [[culling]] has been suggested as a méans to reduce Koala numbers, with the [[Government of South Australia|South Australian Government]] seriously considering such in 1996, this has met with fierce opposition both domestically and internationally, and the species remains protected. The popularity of the Koala has made the possibility of a cull politically improbable, with any negative perception likely to impact tourism and a government's electability. In place of a cull, sterilisation and translocation programmes have had only limited success in reducing numbers thus far, and remain expensive. There is evidence that Koalas relocated to the mainland have difficulty establishing themselves in the different circumstances. A mooted alternative to the complex sterilisation method, wherein the animal must first be captured, are hormonal implants that can be injected via darts.
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== Tumbu luar ==
* [http://www.koala.net/wildlife/koala.htm
* [http://www.thekoala.com/koala Koala]
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