The Vertebrate Fauna of Jenolan Karst Conservation Reserve: Final

STUTTERING FROG MIXOPHYES BALBUS
EPBC Act: Vulnerable TSC Act: Endangered Priority in Area: Nil as suspected
species loss-highest if rediscovered
Occurrence in the Survey Area
Suspected species loss. Suitable habitat exists in JKCR
though the stuttering frog may no longer occur. There is a
single Australian Museum record in the Atlas of NSW Wildlife
listed as ‘Jenolan Caves’ from 1974. This record is of low
spatial accuracy and is placed on Jenolan Caves Rd west of
Caves House. It is likely this record is actually from Surveyors
or Camp Creek or the Jenolan River. No recent surveys have
located the species, despite targeted searches, including the
Mixophyes Survey of 1999-2000. This survey looked for
population declines by revisiting known locations and likely
habitat. The survey visited three sites within JKCR in
Stuttering frog. Photo © M. Schulz
December 1999: on the Jenolan River, Camp Creek and
Surveyors Creek. They found no evidence of adult stuttering
frog or their tadpoles. Likewise, subsequent surveys, including this one, have failed to locate this frog
and it may have declined to extinction within the reserve. Nonetheless, this species can be cryptic and
overlooked when conditions are not ideal and future surveys may yet uncover a remnant population.
Regional Conservation Significance
The apparent disappearance of the stuttering frog from JKCR is typical of the decline across the entire
Southern Blue Mountains and indeed the entire the southern portion of its range (Hunter and Gillespie
2006). This species is close to extinction in the wetter forests and rainforests of the Blue Mountains
and Illawarra Escarpment (DECC 2007). Within the Blue Mountains there is a remnant population on
Ruby and Mt Werong Creeks, approximately 30 kilometres to the south-west of JKCR. This population
occurs in relatively dry forest at high altitude, similar to habitat found in JKCR. Otherwise, a single
individual has been photographed in 2002 near Victoria Falls, 35 kilometres to the north east. It is
likely that other isolated populations occur within the Greater Blue Mountains. Elsewhere within the
bioregion it is principally known from rainforests and wet sclerophyll forests in the Watagan Mountains
area on the Central Coast. Given the lack of recent records, the reserve does not contribute
significantly to the regional conservation of this species. However, if this species is rediscovered, as
with other sites within the Southern Blue Mountains, it would be of the highest conservation priority.
Threats in the Survey Area
Changes in water quality and hydrological regimes;
introduction of the Amphibian Chytrid Fungus; loss of
moist forest habitat through inappropriate fire regimes
or weed invasion; predation by foxes and cats; and
predation and habitat disturbance by pigs.
Management Considerations
Maintain and improve water quality and flow
characteristics of waterways within the reserve.
NPWS Rangers and Jenolan Caves Reserve Trust
staff to become familiar with this species and report
any possible sightings.
Conduct further summer surveys specifically
targeting this species on Surveyors and Camp Creek
and on the Jenolan River and any significant
forested tributaries, for instance Stockyard and
Terrace Creek in the north of the reserve, neither of
which have yet been investigated.
Observe frog hygiene protocols (NPWS 2001a)
during any OEH works around waterways.
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The Vertebrate Fauna of Jenolan Karst Conservation Reserve 41