Western Ringtail And The Common Ringtail Possum example essay topic

An Introduction to Possums: The first Australian possum to be seen and collected by a European was a Common Ringtail (Pseudocheirus peregrines) taken by someone on Captain Cook's voyage through the South Pacific in 1770. It was lucky this specimen, now held in the National Natuurhistorisch Museum at Leyden, Netherlands, was not eaten like the first kangaroo. They recorded this animal to the 'opossum tribe' because of the two young within its pouch and it was later linked with the Brazilian Opossum. There has been much confusion between the Australian 'possums' and the American 'opossums', which are two very different and only distant related marsupial groups. If Banks had decided to ask the Aborigines what they called the possum, as he did with the kangaroo, we might have called the Australian possum by a very different name ('too lahs', 'bobucks', or another indigenous name). Finally, after many years of debate, the 'O' was dropped with Australian vernacular usage.

There are now twenty-seven species of possum coming from six different superfamilies throughout Australia. They are easily the most widespread mammals in Australia. Basic Evolution of the Australian Possum: The oldest marsupial fossil was found in North America over one hundred million years ago. From the many years of separation and isolation of the continents came two primary groups of marsupials: Ameridelphians, from the Americas, and the Australidelphians from the Australasia. This proves the distant relationship between the possum and the opossum.

While Australia was drifting north, away from Antarctica, three groups of specimen then evolved from the Australidelphians: Dasyuromorphia (carnivorous marsupials), Peramelemorphia (bandicoots and billies), and Diprotodontia (more specialized herbivorous marsupials). Diprotodontia has two suborders: Vombatidae (wombats and koalas) and Phalangeridida (possums, pygmy possums, gliders, honey possums, all kangaroos, wallabies, and potoroos). The name Diprotodontia was achieved by the characteristic of the two long incisors on the bottom jaw of these marsupials (di = 2, proto = front, and dont = teeth). Another feature of this order was the syndactylus hind feet, which is the second and third digits fused together making it look like one digit with two claws. The oldest possum fossil was found in Lake Eyre and Lake Frome basins of northern South Australia and dated back 26-23.3 million years ago. These particular fossil beds were deposited during the time when the country was covered in rainforests, and the River sleigh site in western Queensland is also a fossil bed for early discoveries of possum evolution.

This site, dating back almost twenty million years, contained primitive and extinct fossils. Most of the families are still represented today. The rainforest became less abundant and began to move north with the continent, possums had only a few choices: One, they could die; Two, they could travel with the rainforest; or Three, they could adapt to the new more arid environment. Many of them died and are now extinct, few adapted and most remain in the rainforests today in the north. Location: Due to the need to adapt to the new and ever-changing environments, the possum's will to survive has made it the most widespread marsupial of all of Australia. One species lives on every substantial island east and west of Papua New Guinea, on New Guinea's mainland, Australia, Tasmania, and recently introduced to New Zealand (much to their dismay) in 1837.

Although, the possum originally evolved in Australia, it has had to take a liking to the New Guinea area, which is mostly covered in rainforests. There are 26 species of possum found in New Guinea and its surrounding island, 18 of which cannot be found elsewhere. Twenty-seven species are found throughout mainland Australia, five occurring elsewhere, with the most diversity found in the montane rainforests of northern Queensland. Body Characteristics: Possums have originated in rainforests, so it would only make sense that they are mostly arboreal herbivores (tree-dwelling plant eaters).

The syndactylus hind feet allow the possum to climb trees and grip branches while travelling. Their diprotodont lower incisors and no lower canines constricts their diet to mainly herbivorous structures. The prehensile tail is also an important trait of the possum and quite often serves as a fifth hand, assisting in balance, as well as wrapping around branches and even sometimes powerlines. Possums have a tapetum lucidum that allows them to see at night (nocturnal). This layer of pigment in the eye reflects incoming light back to the rod-shaped photoreceptors on the retina, which detect low levels of light, allowing them to see well in the dark. All female possums have (like most other marsupials) a forward opening pouch on the underside of their body, which is in line with the hips and acts as a placenta for the underdeveloped young.

Almost all of them have two teats hidden inside the pouch. Most possums only raise one young at a time, so only use one teat. The Common Ringtail and Cuscus es have four teats and generally raise two to three young at one time. Once a female has raised a young, she usually has a rusty, stained appearance on the fur around the pouch. Possums have evolved and changed with the time. They have become the only marsupial capable of gliding.

The possum has even evolved into three groups of gliding possums: the petaurids, the acrobatics, and the pseudochirids. Their evolving like this may have been because of the adaptation needed for the non-interconnected forests in different areas that prevented them from climbing from tree to tree. A gliding membrane (patagium) that stretches between their front and back legs is necessary for this. The muscle fibres running through the connective tissue control altitude and retract the membrane when it is not in use.

The Greater Glider's patagium joins elbow to ankle (gliding with its elbows bent), while the smaller gliders glide with arms extending out with their patagium running from wrist to ankle. Families of Possums and their Species: There are six superfamilies making up a total of twenty-seven species residing in the mainland of Australia. The family Burramyidea with its species of pygmy possums consists of mountain pygmy possum, little pygmy possum, western pygmy possum and the eastern pygmy possum. The family Tarsipedidea only includes the honey possum, as does the family Acrobatidae with its feathertail glider.

The Petauridae family includes the stripped possum, leadbeater's possum, yellow-bellied glider, sugar glider, mahogany glider, and the squirrel glider. The Pseudocheiridae family has the greater glider, lemuroid ringtail, rock ringtail, green ringtail, Daintree River ringtail, Herbert River ringtail, western ringtail, and the common ringtail possum. The last family, the Phalangeridae family consists of the common spotted cuscus, scaly-tailed possum, southern common cuscus, mountain brushtail, coppery brushtail, northern brushtail and the common brushtail. Examples of Families: There is one possum example from each of the six families. The species chosen was done so on interesting fact or commonality to the area (Australia). Burramyidae Family: The Western Pygmy-possum is found in the southwest of Western Australia, in southern South Australia and in far western Victoria.

They are a secure species (not in danger of extinction). They are larger than they Little Pygmy-possum and have a pure white belly, unlike any other possum. All other possums have a grey-based belly fur. Their scientific name is the Cercartetus concinnous. This possum enter a period of torpor by day and, curled up in a tight ball, and can be removed from its nest, examined, and then placed back into the nest without disturbance.

As many as six young has been found in a single litter and the reproductive cycle of this possum suggests that it lives in an ever-changing environment, probably undergoing cyclic fluctuations in numbers. It may suffer quite high rates of predation. It was once noted that a single domestic cat in the Bunbury area of Western Australia brought thirty individuals into the house in only a few months. Tarsipedidae Family: The Honey-possum, Tarsi pes ro stratus, has a distinctly long snout and tongue. It is greyish-brown with yellow to white underparts. It has a dark dorsal stripe flanked by a lighter brown stripe on each side, features in combination that are very unique.

The Honey-possum is found in southwestern Australia. It is the only land mammal in the world that is entirely nectarivorous (somewhat like the hummingbird). The Honey-possum is the only possum that exhibits embryonic diapause (embryos remaining dormant in the uterus while the mother is lactating), although this is a feature of reproduction in many macropodid (kangaroo and wallaby) species. The newborn young are the smallest mammals known yet remarkably, Honey-possums have the longest sperm of any mammal, including the blue whale. Acrobat idea Family: The Feathertail glider, Dromicia frontal is, is found in eastern Australia (with the exception of Tasmania), from southeastern South Australia to Cape York. They hold a secure status.

The combination of a 'feather tail' and a gliding membrane are unique to this particular species. The tail has a distinct fringe of stiff and elongate hairs protruding from either side. Their gliding membranes are smaller and thicker than any other glider marsupial. They inhabit many forest types - from tall, wet sclerophyll to stunted sclerophyll and woodland.

Although, they are arboreal, they will also forage in shrubs and on tree-trunks that are almost ground level. The Feathertail glider is extremely vulnerable to predation by domestic cats (as well as feral), especially in suburbs of Melbourne and Sydney. Foods consumed by this marsupial are nectar, manna, sap, small insects and foliage. Up to sixteen can utilize a single nest, but the mean group size is three or four.

Groups usually include one or both parents and their offspring. The males are slightly larger than the females, but not necessarily heavier. The female has four teats and a mean litter size of 2.5. Petauridae Family: The Sugar glider, Pa taurus breviceps, is a soft grey marsupial with a black strip running down the sides of its body. If high enough a glider can glide as far as 50 meters.

Adult gliders weigh between 120 to 135 grams. Their tails are used for balance and steering when gliding, but not much else. Sugar gliders are very social animals and usually live in groups of twenty to forty. Their opposable fingers and toes (digits) and forked genitalia (female and male) are quite odd and unique qualities.

They make a wide range of sounds such as chirping, barking, chattering and crabbing. Pseudocheridae Family: The Green ringtail possum, Pseudocheirus archer i, has a greenish, olive colouring because the mixture of black, grey, yellow and white hairs. Its fur is soft and thick. It has two silvery vertebral stripes with white patches under its ears and eyes.

The tail is shorter than the head and body. Its has a distinguished resting posture - curled in a tight ball, gripping the branch with one or both hind feet, sitting on the base of its coiled tail, with its forefeet, face and tip of the tail ticked tightly into its belly (like in the picture above). It is only found in upland rainforests of the wet Tropics region (above 300 m). As an arboreal mammal, it only descends to the ground to traverse a gap between the trees.

It appears to favour rainforests with tangled, t hornless vines. Its diet is exclusively of leaves. The Green ringtail possum is the only possum known to eat figs. The Shinning-leaf Stinging Tree, Pepper wood, Red Tulip Oak, Flame Kurrajong and the False Stinger are preferred trees to hunt leaves from. It is the most solitary of all of the ringtails and is rarely spotted with a mate. They are able to move rapidly through the canopy, running along branches and up narrow swaying vines, but avoiding leaps except across major the forks of major branches.

The female has two teats, but usually only seen with one young from the months of August to November. The two most threatening predators are the Spotted-tailed Quell and the Rufous Owl. Indigenous Australians used to eat these marsupials. One of the biggest hazards to the Green ringtail ed possum is clearing the rainforest, its home. Phalangeridae Family: The Northern Brushtail possum, Trichosurus arnhemensis, is found in the Northern Territory of Australia, as well as the extreme northern part of Western Australia. Its body length is between 35 cm and 55 cm.

The tail adds an additional 25 cm to 40 cm. Females weigh between 1500 g to 3500 g and males weigh between 2000 g and 4500 g. They coat is typically grey in colour, however, can be a reddish brown, copper, or chocolate brown colour as well. The tail is covered in fur, with a hairless underside. The ears are long and oval. Their life expectancy is a mere eleven to thirteen years.

Predators include the carpet python, dingo and monitor lizard. Their diet includes leaves, buds, flowers and fruits. Gestation lasts between seventeen and eighteen days, with a pouch period of four to five months. There is generally one offspring per birth. Weaning takes between six and seven months.

Individuals reach sexual maturity around age one and breed continuously throughout the year. Its moist palms and soles make it an expert climber and give it strong adhesion. The Northern Brushtail Possum is able to live in a variety of habitats such as residential areas, forests, and areas without trees that offer caves and burrows for shelter (wooded areas). This particular marsupial is a low risk, near threatened species. They are said to have negative affects such as damaging flowers in urban areas, damaging buildings, adversely affecting the regeneration of forest and also carrying diseases that are harmful to humans and livestock.

Current Events: The possum being high on cuteness level, but equally high on a nuisance level, has become a bother and worry to many New Zealanders. The Australian brushtail ed possum was introduced into New Zealand in 1837 to establish a fur trade. With conditions being favourable for the possum, it breeds twice in one year and its population is now estimated at a 70 million (in New Zealand). The problem is that these possums are damaging native forests and eating whole canopies of rata, to tara, tit oki, kow hai and kohekohe. They also disturb the nesting areas for birds and eat their young. Dairy and deer farmers worry of possums carry bovine tuberculosis to their livestock.

Possums are a nuisance in suburban gardens and even travel indoor at times. Since the possum is a protected species, people are unable to kill them; they must trap them or call animal control (like we saw in the video - the possum man). Timm traps, a brightly yellow plastic box, are often used for catching the possums. The box will lure them in with a tasty piece of fruit at the end of it and then the door will shut when they enter, leaving the poor little possum unharmed! Another threat to the Australian possum is the export meat industry. The Tasmanian Brushtail possum is under a deep threat.

The Australian Federal Government has approved an export meat industry. There is even a cookbook being sold via Internet. This gentle, inquisitive but shy native marsupial is destined for the Asian dinner table. L Act now to stop the exploitation of this wonderful native creature by writing to: Senator Robert Hill Minister for the Environment Parliament House Canberra ACT 2600 Australia Tell him that this new plan is not acceptable on the grounds that an export meat industry isn't an acceptable or sustainable plan of management for this animal and this will subject hundreds and thousands of possums to extreme cruelty. Conclusion: The possum is a very unique and important species of fauna to Australia. It must not be over looked at all the possum has gone through to stay around.

They have adapted and changed over the millions of years to survive and flourish throughout the country. As the most widespread marsupial to live here, the Australian possum has a will to survive. Learning to live together in harmony with this backyard friend is important and vital to both humans and possums. J

Bibliography

1. Flannery, Timothy. Possums of the World: A Monograph of the Phalangeroidea. GEO Productions Pty Ltd, Chatswood, 1994.
2. K erle, Anne. Possums: The Brushtail, Ringtails and the Greater Glider. University of New South Wales Press Ltd, Sydney, 2001.
3. Nowak, Ronald. Walker's Mammals of the World Vol. 1, 4th ed. The John's Hopkins University Press, Baltimore, 1983.
4. Smith, Andrew. Possums and Gliders. Surry Beatty and Sons, Chipping Norton, 1984.
5. Smith, Barbara. Caring for Possums. Kangaroo Press Pty Ltd, Kent hurst, 1995.
6. Strahan, R. (Ed.) The Mammal of Australia. Reed, Sydney, 1995.