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HISTORY:
- EXTINCTION VS. SURVIVAL -
(page 5)
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Habitat destruction:

    Sleightholme & Campbell (2015) assert that: "Extinctions are often caused by loss of habitat due to agricultural, industrial or urban growth.  European settlement in Tasmania was followed by intensive land clearance for agricultural use, in which swathes of native vegetation were removed.  Since 1803, the areas of greatest loss have been grasslands and grassy woodland, the preferred habitat of the thylacine.  The introduction of sheep onto the thylacine's former range, together with the concurrent removal of its native prey species, would inevitably have had a negative impact on thylacine numbers over time.  Habitat loss, however, is unlikely to have been a major contributing factor in the sudden collapse in thylacine numbers, as even today there are substantial tracts of suitable thylacine habitat within Tasmania".

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land clearance in Tasmania since 1803
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Satellite image of land clearance in Tasmania since 1803.
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Clearance of selected vegetation types since 1803
Broad Vegetation Type Amount pre-European arrival (ha) Amount left in 1996 (ha) TASVEG Amount lost
(ha)
Total percent lost
Rainforest 759,830 560,990 198,840 26
Wet eucalypt forest 1,552,000 883,000 669,000 43
Dry eucalypt forest 2,898,319 1,582,000 1,316,319 45
Grassy woodlands 400,000 40,000 360,000 90
Swamp forest 39,000 19,500 19,500 50
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Source: Draft Nature Conservation Strategy.

Feral dogs:

    Sleightholme & Campbell (2015) state: "Feral dogs were introduced into Tasmania by the early colonial settlers, and like the dingo on the mainland, would have competed with the thylacine for territory and available prey". Mooney (2014, p. 39) states: "Although feral dogs were locally common back then, they were largely restricted to areas near people and could not have competed for food with thylacines across the latter's range".  Sleightholme & Campbell (2015) conclude: "Direct competition with dogs therefore, appears unlikely to have been a pivotal factor in the thylacine's decline.  That said, the majority of sheep kills were made by feral dogs, and the thylacine frequently blamed for these kills.  Such misguided incrimination undoubtedly played a key role in the instigation of the bounty schemes".

    The Mercury of the 1st November 1901 (p. 4), states:

    "The sheep runs behind Ponsonby's Bluff are plagued just now by two wild dogs.  The number of sheep killed by them totals already between 40 and 50.  Men have been out after them, but they are too cunning to come within range of the guns, and again the gullies are so densely timbered that when once they resort thither it is almost an impossible to get at them.  It is to be hoped that they will soon be run down.  They are more destructive than native tigers', because they seem to kill the sheep for sport".

Wild animal trade:

    A significant number of thylacines were caught for the wild animal trade.  It has been estimated that between 1850 and 1933 around 150 to 200 thylacines were trapped for onward sale to zoos and circuses both within Australia and overseas.  Sleightholme & Campbell (2015) maintain that: "During the 19th century, this trade was sustainable, but would have had a negative impact on population numbers as the thylacine became increasingly rare from 1906 onwards".

Hunting and the fur trade:

    There was a substantial fur trade in Tasmania, with vast quantities of animal skins exported to the mainland and overseas.  Tasmania's colder climate produced many of the better quality skins that achieved premium prices when auctioned at market.  Bushmen snared extensively within Tasmania for possum, kangaroo, platypus, devil and wallaby skins.  Thylacines were also killed in the bushmens' snares, with many subsequently submitted for bounty.  With its beautifully striped pelt, the thylacine was also killed to satisfy the demand for floor and carriage rugs, although it must be noted that thylacine "products" were made mainly for the domestic Tasmanian market.  Sleightholme & Campbell (2015) contend: "The significance of the fur trade with respect to depleting thylacine numbers was not in the number of thylacines killed, but in the unrestricted eradication of its prey species".

    The Argus of the 20th March 1879 (p. 5) reports:

  "Something like a local industrial exhibition took place at Brunswick yesterday, on the premises of Mr. S. Clark, furrier, who had invited the mayor and councilors of Brunswick, as well as several of the leading residents, to inspect a varied collection of fur goods made for the approaching winter season.  Native animal skins and some foreign furs are worked up by Mr. Clark in a very tasteful manner into such articles as rugs, mats, muffs, lined slippers, cape, cushions, and tea-cosies.  To make the display somewhat educational the proprietor showed the skins in their unworked condition, during their various processes of manufacture, and in a finished state as furs or leather.  Nearly every kind of animal indigenous to Australia was shown by the exhibitor, from the common kangaroo and opossum to the more rare marsupial wolf from Tasmania or the much-valued platypus, whose fur is considered equal to that of a seal.  The skins of hares, rabbits, and the harmless but necessary cat were also brought into use in various ornamental fashions, the different colours making very pleasing patterns for mats and rugs.  The visitors were highly pleased with all they saw, and those in the fur trade who were present were unanimous in their praise of all that was brought under their notice".

    Michael Sharland, writing in 1941, states:

    "The trapping of wallaby and opossum and smaller game during each 'open' season has not only resulted in a diminished food supply for the thylacine, but has also been responsible directly for the destruction of the animal itself, since it blunders into the snares set on the numerous game trails that intersect the forests and moors, where it expires before the trapper makes his rounds or is shot before the snare can be restored.  There is no demand for its pelt, and in any case the marketing of such would bring heavy penalties, as the animal has been accorded protection by law".

Trade in thylacines for museums:

    Sleightholme & Campbell (2015) state that: "Substantial numbers of thylacines were killed, albeit indirectly, as specimen material for museums and universities".  Sleightholme & Ayliffe (2013) note:

    "A conservative estimate for the total number of thylacines procured for scientific collections is approximately 450 ± 50". 

    Sleightholme & Campbell (2015) continue: "Trade in scientific material intensified from 1900 onwards as the thylacine became increasingly rare.  The trade in specimens, together with the scramble for live thylacines for zoos, would inevitably have impacted on thylacine numbers as the species became scarce" and conclude that "All of the aforementioned factors are deemed to be extinction levers or stressors, and collectively, or in some instances singularly, can push a species beyond the point of recovery.  It is probable therefore that a combination of stressors, acting in unison, brought about the sudden collapse in thylacine numbers, with the epizootic disease providing the catalyst to accelerate this decline".

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References
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