Blac k-striped Flood plains Skink - Egernia slateri virgata
Text by Harald Ehmann and Michelle Watson.
The Black-striped Floodplains skink is one
of the real wildlife mysteries of outback
South Australia. It is known from only
a handful of specimens collected from
somewhere near Oodnadatta in the late
1800’s and early 1900’s. It, along with
another form found in the southern Northern
Territory are considered to be subspecies, but
considerable differences in their colouration
and the distance between their distributions
may warrant them being considered separate
species. A fortuitous discovery of one of these
skinks by an observant rangelands resident
could help solve the mystery that surrounds
these species.
DETECTION AND IDENTIFICATION
Only seven specimens of the Black-striped
Floodplains Skink have been collected,
all before 1914, so there is no first-hand
field knowledge available for this lizard.
The only available photographs are of
preserved specimens.
Observation of the closely related form in the
Northern Territory may provide an indication
of the ecology of the Black-striped Floodplains
Skink in South Australia. The Northern
Territory subspecies is active on warm
mornings or in the late afternoon and warm
evenings. It lives in a complex burrow with
a number of small entrances and one main
entrance, usually dug into steep sloping soil
of a bank or pedestal at the base of shrubs.
It usually leaves an area of loose spoil
and sometimes a pile of scats near the
main entrance.
Museum specimens show that the
Black-striped Floodplains Skink is distinctively
marked with a prominent blackish stripe along
the middle of the back and two similar
narrower parallel stripes. These latter stripes
may be broken into two series of dashes.
The sides are distinctly pale and dark blotched
(see photograph). The belly is pinkish-white
while the darker throat has black speckling.
It is a relatively large skink reaching a total
length of about 23 centimetres and a weight
of 31 grams.
HABITAT AND DISTRIBUTION
The seven known specimens of Black-striped
Floodplains Skink are reported to be from
Oodnadatta, Wantapella Swamp and from
near the Musgrave Ranges, but there is some
uncertainty about these locations.
Wantapella Well on Granite Downs Station
is the only precisely recorded location for the
Black-striped Floodplains Skink. Local runoff
and flood water from Indulkana Creek forms
the Wantapella Swamp. The surface soil is
light and sandy and overlays light clay.
Mulga, Prickly Wattle and Dead Finish
cover the surrounding dune areas while
Nitre Goosefoot, Lignum, Coolibah and
River Red Gum predominate nearer and in
the Swamp area.
POTENTIAL THREATS TO
BLACK-STRIPED FLOODPLAINS SKINK
The Black-striped Floodplains Skink is listed as
Endangered in South Australia and nationally.
However, since there have been no records of
this species since 1914, threatening processes
are not clear.
The sub-species in the Northern Territory
has declined dramatically, possibly due to
small but critical effects including habitat
change, competition, predation and total
grazing pressure. It is possible that the
South Australian Black-striped Floodplains
Skink has been affected by the same
processes. Long-term grazing pressure may
have led to an increase in the aridity of the
Wantapella Swamp, making it more suitable for
other species of lizard that may out-compete
the Black-striped Floodplains Skink.
CURRENT RESEARCH
As more than 50 years have passed since
a Black-striped Floodplains Skink has been
seen, it could be formally considered as
Extinct. However, it is possible that the
Black-striped Floodplains Skink persists as
a relict at one or more sites in the South
Australian Rangelands, and finding one
would allow a more accurate assessment
of its abundance, habitat requirements and
management needs. The discovery of the
Northern Territory subspecies in different
habitats suggests that searches in South
Australia should be widened to include a
variety of habitats not previously considered
suitable for the species.
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