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not a single convincing butchery site has yet been identified, in strong contrast to the
abundance of Moa butchery sites in New Zealand (Martin,
1984
, pp. 391-392) and of
early Holocene bison and mammoth butchery sites in North America (Martin,
1984
).
Arguments put forward to account for the lack of early Australian butchery sites
refer vaguely to past climatic changes or to changes in river behaviour. For example,
Flannery (
1994
, pp. 199-200) refers to erosion, 'the restless Earth' and 'the dynamic
nature of the Earth' to account for the lack of evidence 'relating to howhumans affected
Australia's giant marsupials, birds and reptiles' (op. cit., p. 199). This reasoning is fair
enough, perhaps, but it does not explain why butchery sites survive so well in Africa
from Acheulian times onwards, having successfully endured repeated environmental
changes during that time (Clark,
1982
; Isaac,
1982
). It might be simpler to seek other
and additional causes for the demise of the large marsupials, such as the progressive
desiccation of Australia that set in around 50 ka ago (Cohen et al.,
2010b
), which was
also about the time when humans first moved into Australia (Bowler et al.,
2003
).
Although it is a truism that absence of evidence is not evidence of absence, the lack
of true butchery sites associated with Australian megafaunal remains may simply
indicate that large marsupials were not hunted to extinction but died out from other
causes, such as habitat modification caused by humans burning the vegetation to assist
in hunting.
In order to test these hypotheses, Prideaux et al. (
2007
;
2009
;
2010
) have conducted
a series of elegant and exemplary studies. Acave known forbiddingly as Tight Entrance
Cave in south-western Australia contains the 'richest and most diverse assemblage
of Late Pleistocene vertebrates known from the western two-thirds of Australia'
and is also the 'only site on Earth known to have sampled a mammal community for
100 ka preceding regional human arrival and then subsequently' (Prideaux et al.,
2010
,
p. 22157). Analysis of the stable carbon and oxygen isotopic composition of land snail
shells composed of aragonite (which therefore have not undergone any recrystalliza-
tion or secondary diagenesis) demonstrates significant environmental (and climatic)
change from 70 ka onwards, culminating in the extreme cold temperatures and aridity
of the LGM at around 21 ka. However, the extinctions predate this later extreme event
by some 20,000 years. Counts of coarse and fine charcoal washed into the cave denote
local and regional fire frequency, respectively. The earliest evidence of a human pres-
ence at this site is dated to 49
±
2 ka, while the most recent age for the local presence
of an extinct mammal is 40
2 ka, showing that the extinctions were progressive
and not the abrupt events posited by Paul Martin in his North American Blitzkrieg
model of hunting-induced extinctions (Martin,
1967
). Prideaux et al. (
2010
) conclude
that 'on balance, human impacts (e.g., hunting, habitat alteration) were most likely
the primary driver of the extinctions', but they go on to caution that 'it is equally
probable that the ultimate extinction “cause” was complex, and that landscape burn-
ing and increasing aridity helped fuel the extinction process' (op. cit., p. 22161).
±
