The Vertebrate Fauna of Jenolan Karst Conservation Reserve: Final
The Vertebrate Fauna of Jenolan Karst Conservation Reserve: Final
The Vertebrate Fauna of Jenolan Karst Conservation Reserve: Final
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EASTERN BENTWING-BAT MINIOPTERUS SCHREIBERSII OCEANENSIS<br />
EPBC Act: Not Listed TSC Act: Vulnerable Priority in area: High<br />
Eastern bentwing-bat. Photo © M. Schulz<br />
Eastern bentwing-bats roosting. Photo © N.<br />
Williams<br />
Occurrence in the Survey Area<br />
Common resident with regionally important roosting sites.<br />
This species has recently been revised to M. orianae<br />
oceanensis although it still appears on the NSW and<br />
Commonwealth legislative schedules under its former<br />
name therefore this nomenclature has been retained for<br />
this document. <strong>The</strong> karst system at JKCR provides a wide<br />
diversity <strong>of</strong> caves, overhangs and other features that this<br />
species uses to roost. It is found throughout JKCR<br />
including: Mammoth Flat, Blue Lake, <strong>Jenolan</strong> River<br />
Campsite, McKeowns Valley, Binda Bush cottages,<br />
<strong>Jenolan</strong> River (near Stockyard Creek), <strong>Jenolan</strong> River Trail<br />
dam, the Info Bay trail, Oaky Camp trail (at gate), the<br />
Devil’s Coach House and Surveyors Creek weir. <strong>The</strong> 2011<br />
surveys recorded a large number <strong>of</strong> eastern bentwing-bats<br />
(~1000) in the ‘southern limestone’ area (Paradox Cave).<br />
Approximately 50 animals were also observed within<br />
Mammoth Cave; however guides indicate that numbers<br />
tend to be higher in August and September. Mammoth<br />
Cave may not be used all year around, with researchers<br />
previously recording an absence <strong>of</strong> eastern bentwing-bats<br />
in June (Euston et al. 2009). Due to the extensive area <strong>of</strong><br />
karst, it is likely that further sizable roosts occur<br />
unrecorded within JKCR.<br />
This survey found colonies <strong>of</strong> eastern bentwing-bats at<br />
JKCR to be temporally segregated based on age and/or sex, which is typical <strong>of</strong> the species (Dwyer<br />
1966). No evidence <strong>of</strong> a maternity roost was found during this or previous surveys. It is still possible<br />
that a large maternity roost is present, though this seems increasingly unlikely. No bats captured<br />
during this study showed evidence <strong>of</strong> lactation, although the sample size was relatively low, and the<br />
survey later than ideal. During the maternity period the population at Paradox Cave was male biased<br />
and all females captured were non-reproductive. It is not known if JKCR historically supported a<br />
maternity roost, though Tear Drop Cave has been highlighted as a former maternity cave (E. Holland<br />
pers. comm. to A. Spate). Due to the extensive nature<br />
<strong>of</strong> the cave system at <strong>Jenolan</strong>, it is likely that some<br />
part may have once been suitable. However, early<br />
cave management practices tended to be insensitive<br />
and would have impacted this species.<br />
Ideal maternity sites are thought to require high domed<br />
ceilings, small low entrance passageways, the<br />
propensity to trap metabolic heat released from<br />
roosting bats (Hall and Richards 2003) and a stable<br />
temperature <strong>of</strong> 20-29 degrees centigrade (Dwyer<br />
1963, 1971). None <strong>of</strong> the caves visited during this<br />
survey fulfil these requirements, though Paradox Cave<br />
is thought to be the most suitable. However, this bat is<br />
also known to breed in smaller caves and artificial sites<br />
(Hoye 2000 and R. Williams pers. comm.) meaning<br />
smaller sites remain a possibility at <strong>Jenolan</strong>. Banding<br />
data shows bats from <strong>Jenolan</strong> have moved to or from<br />
maternity sites at Wee Jasper, Bungonia and mine<br />
adits in the Warragamba catchment (P. Wilson pers.<br />
comm.). Elsewhere in NSW maternity sites occur at<br />
Willi Willi caves and Nimbin (Hall and Richards 2003)<br />
and in a mine in the Hunter Valley (Hoye 2000).<br />
Seasonal movements <strong>of</strong> eastern bentwing-bats are<br />
<strong>The</strong> <strong>Vertebrate</strong> <strong>Fauna</strong> <strong>of</strong> <strong>Jenolan</strong> <strong>Karst</strong> <strong>Conservation</strong> <strong>Reserve</strong> 77