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| Phascolarctos cinereus (Goldfuss, 1817) |
The Koala (Phascolarctos cinereus) is a thickset arboreal marsupial herbivore native to Australia, and the only extant representative of the family Phascolarctidae. Georg August Goldfuss (Goldfuß April 18 1782 &ndash October 2 1848) was a German Palaeontologist and Zoologist Year 1817 ( MDCCCXVII) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian calendar (or a Common Arboreal is a word meaning "related to or resembling trees" Marsupials are an Infraclass of Mammals characterized by a distinctive pouch (called the marsupium) in which females carry their young through Herbivory is a form of Predation in which an Organism, known as a herbivore, consumes principally Autotrophs ref name=Campbell>Campbell For a topic outline on this subject see List of basic Australia topics. Extant is a term commonly used to refer to Taxa (such as Species, genera or families) that are still in existence (living In Biological classification, family ( Latin Phascolarctidae is a family of marsupials of the order Diprotodontia, consisting of only one extant species the Koala, six well known fossil species
The Koala is found in coastal regions of eastern and southern Australia, from near Adelaide to the southern part of Cape York Peninsula. Adelaide is the capital and most populous city of the Australian state of South Australia, and is the fifth largest city in Australia with a This article is about the peninsula located in the Australian state of Queensland; it should not be confused with either Yorke Peninsula in South Australia Populations also extend for considerable distances inland in regions with enough moisture to support suitable woodlands. The Koalas of South Australia were largely exterminated during the early part of the 20th century, but the state has since been repopulated with Victorian stock. South Australia is a state of Australia in the southern central part of the country The twentieth century of the Common Era began on The Koala is not found in Tasmania or Western Australia. Tasmania is an Australian island and state of the same name It is located south of the eastern side of the Continent, being separated from it by Bass Western Australia is a state occupying the entire western third of the Australian continent.
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Names
The word koala comes from Dharuk gula. The Sydney Language, also referred to as Dharug or Iyora, is an extinct Australian Aboriginal language that was spoken Although the vowel /u/ was originally written in the Latin alphabet as "oo" (in spellings such as coola or koolah), it was changed to "oa" possibly due to an error. [3] The word is erroneously said to mean "doesn't drink". [3]
When first adopted by English speakers, the name Koala bear became popular, as this roughly evoked the species' appearance to people unfamiliar with it. Although taxonomically inaccurate, the name Koala bear is still in common use today. [4] Other descriptive English names based on "bear" have included monkey bear, native bear, and tree-bear. [3]
The scientific name of the koala's genus, Phascolarctos, is derived from Greek phaskolos "pouch" and arktos "bear". A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Greek (el ελληνική γλώσσα or simply el ελληνικά — "Hellenic" is an Indo-European language, spoken today by 15-22 million people mainly Its species name, cinereus, is Latin and means "ash-coloured". In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. Latin ( lingua Latīna, laˈtiːna is an Italic language, historically spoken in Latium and Ancient Rome. [5]
Variation
Although three subspecies have been described, these are arbitrary selections from a cline and are not generally accepted as valid. Kangaroo Island is Australia 's third largest Island - after Tasmania and Melville Island. In Zoology, as in other branches of Biology, subspecies is the Taxonomic rank immediately subordinate to a Species. Following Bergmann's Rule, southern individuals from the cooler climates are larger. In Zoology, Bergmann's rule is an ecogeographic rule that correlates Latitude with body mass in animals 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 forearms, and has a more prominently light-coloured ventral side and fluffy white ear tufts. Typical and New South Wales Koala weights are 12 kg (26 lb) for males and 8. 5 kg (19 lb) for females. In tropical and sub-tropical Queensland, however, the Koala is smaller (at around 6. Queensland is a state of Australia, occupying the north-eastern corner of the mainland continent 5 kg (14 lb) for an average male and just over 5 kg (11 lb) 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 unclear, although almost certainly they descended from terrestrial wombat-like animals. Koala fossils are quite rare, but some have been found in northern Australia dating to 20 million years ago. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. During this time, the northern half of Australia was rainforest. Rainforests are Forests characterized by high Rainfall with definitions setting minimum normal annual rainfall between 1750–2000 mm (68-78 inches The Koala did not specialise in a diet of eucalypts until the climate cooled and eucalyptus forests grew in the place of rainforests. The fossil record indicates that before 50,000 years ago, Giant Koalas inhabited the southern regions of Australia. The Giant Koala ( Phascolarctos stirtoni) was an arboreal Marsupial which existed in Australia during the Pleistocene epoch The Koala fills the same ecological role as the sloth of South America. The living sloths comprise six Species of medium-sized Mammals that live in Central and South America belonging to the families
Physical description
The Koala is broadly similar in appearance to the wombat (their closest living relatives[1]), but has a thicker coat, much larger ears and longer limbs. The Koala has large, sharp claws to assist with climbing tree trunks. Weight varies from about 14 kg (31 lb) for a large southern male, to about 5 kg (11 lb) for a small northern female. Koala's five fingers are arranged with opposable thumbs, providing better gripping ability. The thumb is the medial -most digit of the hand The English adjective for thumb is pollical The first two fingers are positioned in apposition on the front paws, and the first three fingers for the hind paws[6]. The Koala is one of the few mammals (other than primates) that has fingerprints. A fingerprint is an impression of the friction ridges of all or any part of the finger Koala fingerprints are similar to human fingerprints; even with an electron microscope, it can be quite difficult to distinguish between the two. [7]
The teeth of koalas are adapted to their herbivorous diet, and are similar to those of other diprotodont marsupials, such as kangaroos and wombats. Diprotodontia (Greek meaning "two front teeth" is a large order of about 120 Marsupial mammals including the Kangaroos A kangaroo is a Marsupial from the family Macropodidae (macropods meaning 'large foot' They have sharp incisors to clip leaves at the front of the mouth, separated from the grinding cheek teeth by a wide diastema. Incisors (from Latin incidere, "to cut" are the first kind of Tooth in Heterodont Mammals They are located in the Premaxilla Diastema is a gap or space between two Teeth. The term is most commonly applied to be an open space between the upper Incisors (front teeth The dental formula for koalas is:
| Dentition |
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| 3. Dentition is the development of Teeth and their arrangement in the Mouth. 1. 1. 4 |
| 1. 0. 1. 4 |
The male koala, like many marsupials, has a bifurcated penis. The penis (plural penises, penes The female has two lateral vaginae, a feature unique to the Koala, and it has two separate uteri which is common to all marsupials. The vagina (from Latin, literally " Sheath " or " Scabbard " is a fibromuscular tubular tract leading from the Uterus The uterus (from the Latin word for womb) is the major Female reproductive organ of most Mammals including Humans One end the [8]
The brain in the ancestors of the modern Koala once filled the whole cranial cavity, but has become drastically reduced in the present species, a degeneration scientists suspects is an adaptation to a diet low in energy[1]. The brain is the center of the Nervous system in animals All Vertebrates and the majority of Invertebrates have a brain The cranial cavity, or intracranial space, is the space formed inside the Skull. One of the smallest in marsupials with no more than 0. 2% of its body weight[2], about 40% of the cranial cavity is filled with cerebrospinal fluid, while the brain's two cerebral hemispheres are like "a pair of shrivelled walnut halves on top of the brain stem, in contact neither with each other nor the bones of the skull. Cerebrospinal fluid ( CSF) Liquor cerebrospinalis, is a clear Bodily fluid that occupies the Subarachnoid space and the Ventricular system A cerebral hemisphere ( hemispherium cerebrale) is defined as one of the two regions of the Brain that are delineated by the body's median plane. Walnuts (genus Juglans) are Plants in the family Juglandaceae. The brain stem (or brainstem) is the lower part of the Brain, adjoining and structurally continuous with the Spinal cord. It is the only animal on Earth with such a strangely reduced brain. "[9]
It is generally a silent animal, but males have a very loud advertising call that can be heard from almost a kilometre away during the breeding season. When under stress, Koalas may issue a loud cry, which has been reported as similar to that of a human baby. [10] There is little reliable information about the lifespan of the Koala, but in captivity they have been observed to reach the age of 18 years. [6]
The inverted thumbs on the Koala's back feet help for grip while the koala changes branches or eats with its front hands.
Life cycle
Females reach maturity at 2 to 3 years of age, males at 3 to 4 years. If healthy, a female Koala can produce one young each year for about 12 years. Gestation is 35 days. Gestation is the carrying of an Embryo or Fetus inside a Female Viviparous Animal. Twins are very rare; the world's first confirmed identical twin koalas, named "Euca" and "Lyptus", were born at the University of Queensland in 1999. The University of Queensland (UQ is one of Australia's premier learning and research institutions [11][12] Mating normally occurs between December and March, the Southern Hemisphere's summer. Southern Hemisphere is the half of a Planet that is South of the Equator —the word hemisphere literally means 'half ball'
A baby Koala is referred to as a joey and is hairless, blind, and earless. A joey is any infant Marsupial. Marsupials have an extremely short Gestation period and the joey is 'born' basically in a fetal state At birth the joey, only a quarter of an inch long, crawls into the downward-facing pouch on the mother's belly (which is closed by a drawstring-like muscle that the mother can tighten at will) and attaches itself to one of the two teats. Teat is an alternative word for the Nipple of a Mammary gland, in humans referred to as a Breast, from which Milk is discharged Young remain hidden in the pouch for about six months, only feeding on milk. During this time they grow ears, eyes, and fur. The joey then begins to explore outside of the pouch. At about this stage it begins to consume small quantities of the mother’s "pap" (formerly thought to be excrement, but now thought to come from the mother's caecum) in order to inoculate its gut with the microbes necessary to digest eucalypt leaves. The cecum or caecum (from the Latin caecus meaning Blind) is a pouch connected to the Ascending colon of the Large [13] The baby Koala will remain with the mother for another six months or so, riding on her back, and feeding on both milk and eucalypt leaves until weaning is complete at about 12 months of age. Young females disperse to nearby areas at that time; young males often stay in the mother's home range until they are two or three years old.
Ecology and behaviour
The Koala lives almost entirely on eucalypt leaves. Lone Pine Koala Sanctuary is located in the Brisbane suburb of Fig Tree Pocket. Queensland is a state of Australia, occupying the north-eastern corner of the mainland continent Eucalypts are woody plants belonging to three closely related genera Eucalyptus, Corymbia and Angophora. This is likely to be an evolutionary adaptation that takes advantage of an otherwise unfilled ecological niche, since eucalypt leaves are low in protein, high in indigestible substances, and contain phenolic and terpene compounds that are toxic to most species. In Ecology, a niche (pronounced nich nēsh or nish A shorthand definition of niche is how an organism makes a living Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Terpenes are a large and varied class of Hydrocarbons, produced primarily by a wide variety of plants particularly Conifers though also by some insects such Like wombats and sloths, the Koala has a very low metabolic rate for a mammal and rests motionless for about 16 to 18 hours a day, sleeping most of that time. The living sloths comprise six Species of medium-sized Mammals that live in Central and South America belonging to the families Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life. Mammals ( class Mammalia) are a class of Vertebrate Animals characterized by the presence of Sweat glands, including sweat glands Koalas that are disturbed are known to be violent, their teeth and claws capable of causing considerable injury to humans; special handling requirements are as such applicable. [14]
Handling of koalas has been a source of political contention due to these risks, which can also cause harm to the koala as well. [15]Koalas spend about three of their five active hours eating. Feeding occurs at any time of day, but usually at night. An average Koala eats 500 grams (18 oz) of eucalypt leaves each day, chewing them in its powerful jaws to a very fine paste before swallowing. The liver deactivates the toxic components ready for excretion, and the hind gut (especially the caecum) is greatly enlarged to extract the maximum amount of nutrient from the poor quality diet. Excretion is the process of eliminating waste products of Metabolism and other non-useful materials The cecum or caecum (from the Latin caecus meaning Blind) is a pouch connected to the Ascending colon of the Large Much of this is done through bacterial fermentation: when young are being weaned, the mother passes unusually soft faeces, called pap, which is rich in these bacteria, thus passing these essential digestive aids on to her offspring. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Fermentation is the process of deriving energy from the oxidation of organic compounds such as carbohydrates using an endogenous electron acceptor which is Feces, faeces, or fæces (see spelling differences) is a waste product from an animal's digestive tract expelled through the Anus
The Koala will eat the leaves 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 seasonal swamps and watercourses that meander across the dry inland plains allows the Koala to exist in surprisingly arid areas. Eucalyptus viminalis, Manna Gum, also known as White Gum, Ribbon Gum or Viminalis is an Australian eucalypt Grey Gum ( Eucalyptus punctata) is a favoured food of the Koala in South East Queensland and eastern New South Wales, where it specialises Tallowwood ( Eucalyptus microcorys) is a Eucalypt species common in New South Wales and Queensland, Australia. The River Red Gum ( Eucalyptus camaldulensis) is a tree of the genus Eucalyptus. In general terms the Climate of a local or region is said to be arid when it is characterized by a severe lack of available Water, to the extent of hindering Many factors determine which of the 680 species of eucalypt trees the Koala eats. 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.
Conservation status
The Koala was hunted almost to extinction in the early 20th century, largely for its fur. Millions of furs were traded to Europe and the USA, and the population has not recovered from such decimation. Extensive cullings occurred in Queensland in 1915, 1917 and again in 1919 when over one million Koalas were killed with guns, poison and nooses. [16] The public outcry over the cullings was most likely the first wide-scale environmental issue that rallied Australians. As with other countries there are a number of environmental issues in Australia. [16] Despite the growing movement to protect native species, the drought of 1926-28 lead to the another 600 000 Koalas being killed during a one-month open season in August 1927. Hunting is the practice of pursuing Animals for Food, Recreation, or Trade. [16]
Today, habitat loss and the impacts of irresponsible urbanisation (for example dog attacks and traffic accidents) are the leading threats to the survival of koalas. A habitat (which is Latin for "it inhabits" is an Ecological or environmental area that is inhabited by a particular Species. In recent years, some colonies have been hard hit by disease, especially chlamydia. The Koala requires large areas of healthy, connected forest and will travel long distances along tree corridors in search of new territory and mates. The increasing human population of the coastal parts of the continent continues to cut these corridors by agricultural and residential development, forestry and road-building, marooning Koala colonies in decreasing areas of bush. The long term viability of koalas is therefore threatened by genetic weakness. The Australian Koala Foundation has mapped 40,000 km² (15,000 sq mi). The Australian Koala Foundation (AKF is an international scientific organisation that aims to diminish the threats to the survival of Koalas and in doing so raise the awareness of land for Koala habitat and claims it has strong evidence to suggest wild Koala populations are in serious decline throughout the species natural range. Although the species covers a massive area, only 'pieces' of Koala habitat remain. These pieces need to be managed, protected and restored in a coordinated way. Presently, many are being lost to weeds, cleared for agriculture, or carved up by developers. Other threats come from logging, poor management, attacks from feral and domestic animals, disease and roads. A feral organism is one that has escaped from Domestication and returned partly or wholly to its wild state
In contrast to the situation on much of the mainland, where populations are declining, the Koalas of many island and isolated populations have reached what some have described as "plague" proportions. On Kangaroo Island in South Australia, Koalas introduced some 90 years ago have thrived in the absence of predators and competition. Kangaroo Island is Australia 's third largest Island - after Tasmania and Melville Island. Combined with an inability to migrate to new areas, this has caused the Koala populations to become unsustainable and threaten 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 least one isolated population of manna. Eucalyptus viminalis, Manna Gum, also known as White Gum, Ribbon Gum or Viminalis is an Australian eucalypt 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 means to reduce Koala numbers, with the South Australian Government seriously considering such in 1996, this has met with fierce opposition both domestically and internationally, and the species remains protected. Culling is the 'selection' (removal and killing of surplus animals from an animal population The form of the Government of South Australia is prescribed in its Constitution which dates from 1856 although it has been amended many times since then 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.
The Koala inhabits four Australian states. Under state legislation, the species is listed as:
- Queensland - Common, or "Least Concern Wildlife" throughout the state, except in the relatively small South East Queensland Bioregion, where it is listed as Vulnerable. [17]
- New South Wales - listed at a state scale as vulnerable, but varying regionally from "secure" to "locally extinct". [18]
- South Australia - classified as Rare. [19]
- Victoria - The koala population in Victoria is considered "large and thriving". [20]
The US Government have declared the koala a threatened species, however the Australian Government has not. A review of the species national conservation status concluded that the koala are not threatened at a national scale, with a population that numbers in the hundreds of thousands. [21] This was the third review undertaken by the federal government that came to this conclusion. Other studies have estimated as few as 80 000 koalas left in the wild, and the Australian Koala Foundation estimates there are around 100,000. The Australian Koala Foundation (AKF is an international scientific organisation that aims to diminish the threats to the survival of Koalas and in doing so raise the awareness The IUCN lists the species as "Lower Risk / Near Threatened". [2]
As with most native Australian animals, the Koala cannot legally be kept as a pet in Australia without a permit. [22]
See also
References
- ^ a b Groves, Colin (16 November 2005). Koala emblems and popular culture deals with the uses which have been made of the image of the Koala such as Coins Emblems Logos The class Mammalia (the mammals is divided into two subclasses based on reproductive techniques egg laying mammals (the monotremes and mammals which give live birth The Colin Groves is Professor of Biological Anthropology at the Australian National University in Canberra, Australia. Events 534 - A second and final revision of the Codex Justinianus is published Year 2005 ( MMV) was a Common year starting on Saturday (link displays full calendar of the Gregorian calendar. in Wilson, D. E. , and Reeder, D. M. (eds): Mammal Species of the World, 3rd edition, Johns Hopkins University Press, 43. ISBN 0-801-88221-4.
- ^ a b Australasian Marsupial & Monotreme Specialist Group (1996). Koala. 2006 IUCN Red List of Threatened Species. The IUCN Red List of Threatened Species (also known as the IUCN Red List or Red Data List) created in 1963 is the world's most comprehensive inventory of the global IUCN 2006. Retrieved on 2006-05-09. Year 2006 ( MMVI) was a Common year starting on Sunday of the Gregorian calendar. Events 1457 BC - Battle of Megiddo (15th century BC between Thutmose III and a large Canaanite coalition under the King of
- ^ a b c Dixon, R. M. W. ; Moore, Bruce; Ramson, W. S. ; Thomas, Mandy (2006). Australian Aboriginal Words in English: Their Origin and Meaning, 2nd ed. , South Melbourne: Oxford University Press. ISBN 0-19-554073-5.
- ^ Leitner, Gerhard; Sieloff, Inke (1998). "Aboriginal words and concepts in Australian English". World Englishes 17 (2): 153–169. doi:. A digital object identifier ( DOI) is a permanent identifier given to an Electronic document.
- ^ Kidd, D. A. (1973). Collins Latin Gem Dictionary. London: Collins, 53. ISBN 0-00-458641-7.
- ^ a b Martin, Roger (1984). in Macdonald, D. : The Encyclopedia of Mammals. New York: Facts on File, 872-875. ISBN 0-87196-871-1.
- ^ Henneberg, Maciej; Lambert, Kosette M. , Leigh, Chris M. (1997). "Fingerprint homoplasy: koalas and humans". naturalSCIENCE. com 1.
- ^ Dawson, T. J. ; Finch, E. , Freedman, L. , Hume, I. D. , Renfree, M. , Temple-Smith, P. D. . "Fauna of Australia; 17. Morphology and Physiology of Metatheria": pp. 51, 53.
- ^ Flannery, T. F. (1994). The Future Eaters: An ecological History of the Australasian Lands and People. Sydney: Reed New Holland, 86.
- ^ Facts about Koalas
- ^ Koala Research
- ^ University of Queensland Koala Study program
- ^ Martin, Roger; Handasyde, Kathrine Ann (1999). The Koala: Natural History, Conservation and Management, 2nd ed. , Australian Natural History Series, UNSW Press, pp. 64-65. ISBN 0868405442.
- ^ Acrobat Distiller, Job 4
- ^ Koalas Welfare - 16/11/1995 - ADJ - NSW Parliament
- ^ a b c Evans, Raymond (2007). A History of Queensland. Port Melbourne, Victoria: Cambridge University Press, 168. ISBN 9780521876926.
- ^ Queensland Parks and Wildlife Service. EPA/QPWS Koala designation.
- ^ New South Wales Parks and Wildlife Service. NSWPWS Koala designation.
- ^ Australian Koala Foundation. The Australian Koala Foundation (AKF is an international scientific organisation that aims to diminish the threats to the survival of Koalas and in doing so raise the awareness Koala conservation status (FAQs).
- ^ Department of Sustainability and the Environment. Victorian Koala designation.
- ^ Australian Government. Environmental assessment of koala's conservation status.
- ^ Australian Koala Foundation. The Australian Koala Foundation (AKF is an international scientific organisation that aims to diminish the threats to the survival of Koalas and in doing so raise the awareness Frequently asked questions (FAQs).
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