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
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".
Satellite image of land
clearance in Tasmania since 1803.
of selected vegetation types since 1803
pre-European arrival (ha)
left in 1996 (ha) TASVEG
Source: Draft Nature
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".
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
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:
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".
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)
"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".