Going into bat for cave creatures

Original article publised here in Central Western Daily by Ian Curtis

I’ve caved at Cliefden for many years, having been introduced to the area when I moved to Orange  in 1975.

In the early days, as with most other beginning cavers, it was the wonder of the cave formations, the camaraderie and the challenges presented that drew me underground. 

More experienced cavers widened my interest by pointing out the creatures that lived near and within the caves: spiders, centipedes, frogs and bats. 

They informed me that two species of microbats were known to inhabit the caves and scientific work had been done banding bats in the 1960s. 

I bought the Australian Karst Index to find out what was known of the bats and learnt that Barbara Dew, a Canberra scientist, had identified two species: Miniopterus schreibersii (eastern bentwing) and Rhinolophus megaphyllus (eastern horseshoe) and noted that five caves were used by bats.

The eastern bentwing had not been known in the Central West prior to this study, was vulnerable, and used at least one cave as a maternity site.

Another was used as an overwintering site for a population that migrates to Wee Jasper to their maternity cave.

In late 2014, with the caves threatened by a proposed new dam on the Belubula, scientists hastened to restudy the area. 

The local caving club the Orange Speleological Society (OSS), which had been founded in 1955, was asked to help. Detectors were set up at cave entrances and checked and moved over a number of nights.

Initial findings were mind-boggling. Every cave recorded large numbers, all in the hundreds. Two recorders on the river (low and high) recorded 1320 and 1400 respectively. One cave, a maze close to the river,  recorded 1200 one night.

All machines, generally set up to record for two sessions, had flat batteries after only one!

Recordings were sent to Sydney for analysis. Eighteen species were identified from their calls and six, possibly seven, are protected under the NSW Threatened Species Conservation Act,  1995.

Experts confirm this is a microbat hotspot on the call data collected. These data have been forwarded to BioNET (the NSW Wildlife Atlas) for listing and should soon be made available for any interested person to find. 

I found I wanted to know more about bats so got onto the web. The Australian Museum site informed me Australia has about 90 species of microbat.

The Queensland government Department of Environment and Heritage Protection site calls them ‘the insect terminators’ and told of how one species of bat had been recorded eating 1200 tiny fruit flies in an hour - one every three seconds - while on the wing. They forage up to 15 kilometres from their roost site. 

Numbers decline, I learnt, because of habitat loss (clearing of vegetation, inappropriate fire regimes, land degradation from agriculture) and disturbance of roost sites caused by tourism, mining activities, recreational caving and land clearing. 

The Belubula valley, beautiful in its own right, has since white settlement traditionally been a sheep area. Today, however, on its banks and heights, vineyards have sprung up - probably the most well-known of which is Angullong. 

Should a dam be built on the Belubula, or mining begin in the area, the fear is that the bats will be dispersed or, worse still, exterminated. Should this happen local vineyards will be adversely affected as well as other areas to which these bats travel. Without bats protecting fruit from insects viticulturists will need to resort to chemical control measures. 

The study continues. Although I am now an experienced caver in my 70s I still enjoy the wonder of the caves but have a deeper appreciation of their values and beauties.

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