bramble-cay-melomys-survey-report

“A taxon is Extinct when there is no reasonable doubt that the last individual has died. A
taxon is presumed Extinct when exhaustive surveys in known and/or expected habitat, at
appropriate times (diurnal, seasonal, annual), throughout its historic range have failed to
record an individual. Surveys should be over a time frame appropriate to the taxon’s life cycle
and life form.”
Under the Commonwealth’s EPBC Act, definitions for the categories of extinct and extinct in the wild
are:
(1) A native species is eligible to be included in the extinct category at a particular time if, at
that time, there is no reasonable doubt that the last member of the species has died.
(2) A native species is eligible to be included in the extinct in the wild category at a particular
time if, at that time:
(a) it is known only to survive in cultivation, in captivity or as a naturalised population
well outside its past range; or
(b) it has not been recorded in its known and/or expected habitat, at appropriate seasons,
anywhere in its past range, despite exhaustive surveys over a time frame appropriate to
its life cycle and form.
Queensland’s Nature Conservation Act 1992 prescribes native wildlife as being extinct in the wild if:
(a)
(b)
there have been thorough searches conducted for the wildlife; and
the wildlife has not been seen in the wild over a period that is appropriate for the life
cycle or form of the wildlife.
In this particular case, the recent surveys of Bramble Cay were both ‘thorough’ and ‘exhaustive’ and
sampled all ‘known habitat’ at appropriate times, and represented the full extent of the known historic
range of the Bramble Cay melomys. What follows in this and the subsequent section relates to those
parts of the above IUCN and EPBC Act definitions concerning ‘expected habitat’.
Although it is now certain that the Bramble Cay melomys is no longer extant on Bramble Cay, the
possibility that the species occurs elsewhere on islands in the Torres Strait deserves serious
consideration. Arguing against such a notion, it is now 170 years since the existence of the species on
Bramble Cay was first reported (Sweatman unpublished), and more than 90 years since the Bramble
Cay melomys was formally described (Thomas 1924), and yet in all that time no other population has
been discovered. Lee (1995) stated:
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