The Western Woodlands Project

Pilliga Bats - no time to lose

DR HARRY PARNABY* warns of the threats to the Pilliga Bat fauna - an important part of our National Bat Estate - should their habitats not be preserved. The following excerpts are from the paper he delivered at the Revealing the Pilliga seminar, at the Royal Botanical Gardens, in April this year...

Most bat species depend on hollows in old trees.

About 75% of Pilliga bat species depend on hollows in old trees for daytime shelter. Hollows do not form in younger trees and tree age is a central issue for bat conservation planning, particularly given the slow growth rates and durable timbers of inland trees.

It is obvious from the growth form of trees and the types of hollows they contain that contemporary Pilliga forests and woodlands are ancient. Average longevities are not known, but are likely to be about 400 to 1000 years old. Fast-growing coastal Blackbutt do not form small hollows until about 180 years and take at least 250 years for larger hollows and it could be much longer for inland species.

The 'forestry boys' have been conspicuously silent about tree age in the public forest debate. Little wonder, as an appreciation of the likely great age typically attained by trees lays doubt about claims of sustainable forest management - trees with hollows are seen as effectively a finite resource and forestry operations are for all practical purposes mining operations.

A related issue is the carefully nurtured mythology that the Pilliga forests are regrowth forests from the 1890s. This is absolute nonsense but has the dual advantage of negating the issue of conserving old growth attributes, and if it's a regrowth forest, then what's all the fuss about current logging? Why has the forestry profession been so slow to dispel this outrageous myth?

Convenient misconceptions about bats

Legend has it that bats are versatile and highly adaptable generalists and so do not have specific dietary or roosting requirements. It is even claimed that they are not an extinction prone group. What a relief, and how convenient - this is the type of fauna that industry can work with! However, I am not aware of any valid evidence to support such views and there is certainly no proof. For example, the Lesser Long-eared Bat is not considered of conservation concern.

The so-called evidence to support this view is that it is your classic widespread and common bat, and has been found roosting in a wide range of unlikely places such as under bark, under bags in a shed, in fence posts etc. It is assumed to be a dietary generalist, yet little is known of its dietary requirements! Although males will roost opportunistically, radio-tracking studies reveal that females have very specific roost requirements for maternity colonies - hollows of the largest old trees.

This 'versatile' bat actually has very specific requirements and is highly vulnerable. The fact that it is common and widespread does not necessarily mean it is secure - loss of critical requirements can lead to sudden decline. Large old trees are in rapid decline. This leads to the issue of burden of proof. There are two sets of rules: a very high level of scientific proof is demanded from those who stand in the way of industry, yet pro-industry advocates often require no evidence, least of all proof, and their claims are presented as self-evident truisms.

How to deceive the public about threatened bats

Here is a very simple example of how to deceive the public about the conservation status and survival prospects of bats in the Pilliga, using the Greater Long-eared Bat:

This species is listed as Vulnerable under the Threatened Species Conservation Act; however, it is common and widespread in the Pilliga and is recorded from the Pilliga Nature Reserve.

No lies required - the trick lies in the unambiguous implications which draw on a range of carefully nurtured public misconceptions and false assumptions. If it is common and widespread, it is implied that it cannot be threatened and so is not of conservation concern - and doubt is cast on the validity of its Vulnerable status. Yet many extinct species were widely distributed and abundant shortly before extinction.

A few records from the Reserve are supposed to indicate that the species is safely conserved in perpetuity yet there is no indication that the species can survive there - does the reserve contain a viable population? What proportion of essential resources are outside the reserve boundary? Bats often roost in one habitat and forage in a different habitat yet we have not defined the key habitats of these species.

More stringent forestry prescriptions and more reserves required

Informed debate is hindered because the public is fed a constant diet of misinformation about impacts of forestry operations on sensitive fauna such as bats. Good timber areas are also prime fauna habitat because both respond to areas of high productivity.

It is time we stopped pretending that intensive forestry activities can be maintained as well as ensuring the continued survival of vulnerable fauna. The current Pilliga nature reserves are not representative of the Pilliga forests.

Uncertainties about the critical ecological requirements of bats means that logging prescriptions must allow for a large margin for error in conserving ecological needs for sensitive fauna. A much larger proportion of forest will need to be excluded from forestry activities, in tandem with a greatly expanded reserve system - otherwise it is tinkering at the edges of the problem.

Unless this is done, the majority of forest bats in the Pilliga are jeopardised, including species that are currently common and widespread, and the survival of the majority of species will largely be a matter of chance.

HARRY PARNABY

Fauna consultant with a special interest in the Pilliga

For more information:

'Saving What's Left' and the accompanying socio-economic analysis.

Available on www.npansw.org.au/wca-bbs

For Government information on the assessment go to www.racac.nsw.gov.au

Email Cécile and Bev at

View NPA's integrated tourism concept "the Orana Loop Initiative" for Brigalow and the Orana region

Last update: 15/05/03

Contact