The Threatening of Australias Marsupials :: Endangered Species Animals Nature Essays

The Threatening of Australias MarsupialsAbout fifty per centum of all mammal species worldwide to keep back become extinct in the last 200 years commence been from Australia, giving Australia the worst get down for mammal conservation of some(prenominal) country or continent. Of a integrality 245 mammalian species, 59 are listed as extinct, menace, or vulnerable (Short 1994). just about of these extinctions and declines come from two taxonomic groups--the rodents and the marsupials. Be actor marsupials are so abundant and assorted in Australia, I decided to research the endangerment and conservation efforts regarding marsupial species. lux percent of the extinct, endangered, and vulnerable Australian fauna are indeed marsupials accede 1 on the next page lists Australias threatened marsupial species. menace is defined as a species in danger of extinction whose survival of the fittest is unlikely if certain threats continue operating, vulnerable species are believed likely to playact into the endangered category in the near future if threats continue, and to be considered extinct the species has definitely not been located in the wild during the last 50 years (ANPWS 1991). Extinctions and declines have not uniformly affected marsupial species. Terrestrial, medium-sized marsupials in the weight range of 35.0 g to 5.5 kg have proven to be more vulnerable, and omnivores and herbivores have declined to a greater extent than carnivores. Arboreal species such(prenominal) as possums and gliders and species that use rock piles for shelter have been less(prenominal) affected. Most problems with extinction and endangerment occur in the southern arid regularize and the wheat belt of Western Australia while the tropical north of Australia, the mesic northeast and coast of New South Wales, Tasmania, and numerous offshore islands have remained relatively unaffected by local extinctions (Short 1994). The problemsSeven main hypotheses have been put forward to expl ain why species have declined and/or disappeared from mingled parts of Australia, and they include 1) clearing for agriculture, 2) draining and salination of wetlands, 3) grazing and browsing by introduce animals, 4) changed fire regimes, 5) introduced predators, 6) disease, and 7) overkill by hunters (Kennedy 1992). By studying the history of threatened fauna and patterns of decline, experts have come to the conclusion that some of these hypotheses can be dismissed as not being a primary cause of declining populations. For instance, there is no direct evidence that disease has led to any mammal extinctions, though epidemics have been blamed for the decline of carnivorous marsupials in southeastern Australia and Tasmania at the turn of the century.