Barking Owl: Response to SIS 2005, prepared by Cumberland Ecology for Dept of Commerce

Barking Owl (Ninox connivens) Vulnerable (TSC Act)

Response to Species Impact Statement (Cumberland Ecology, 2005)
Clarence Valley Regional Water Scheme


The environmental Planning & Assessment Act 1979 ensures that decision-makers consider known and potential habitat of threatened species, biological and ecological factors and the regional significance of individual populations of threatened species - in this case the barking owl (Draft Recovery Plan 2003)

By the species' rarity; its known inhabitation of the isolated natural forest around and adjoining the proposed Shannon Creek dam site, and the fact that pairs of birds remain in the same area all year round (NSW NPWS 2002) often using the same nest site for many years (Species Profile Vol 3, p3.69), this species should have been treated with extreme caution by the SIS.

Cumberland Ecology (CE) in preparation of this SIS, fails quite dramatically in this regard.

While it is clear that a number of factors need to be addressed in order to help the barking owl's general recovery process, and in this case to ensure its security in the Shannon Creek valley, in statements seemingly tailored to make the species appear common within the Shannon Creek study area CE claims that barking owl "...has been consistently found during work along Shannon Creek (Vol 2, Table 5.2, p5.10); that "potential" habitat for the barking owl occurs throughout the study area, and that the species has been recorded on several occasions, both in the Shannon Creek valley and at other locations to the north; on two occasions in the inundation area in the Shannon Creek valley; on land east of Shannon Creek along the initial proposed access road, and on Shannondale Estate.

These statements appear twice in the 8-Part Test, Vol A, B & C pB.139, and is repeated twice again in the Species Profile, Vol 3, p3.58.

In fact there is just a single record of a single barking owl at Shannon Creek by Greenloaning Biostudies (Vol 3, Fig A.2 Appendix A); just one record of a single bird at Shannon Creek by Edwards J (video evidence), and just 3 records of single bird vocalisations from the Shannondale vicinity over a large period of time (P Edwards, 1984 to 2001). The only result that can be gleaned from these records is that barking owl has been identified within the study area.

There is no suggestion by CE that these records might be of the same bird, or more possibly of just two individuals.

The Draft Recovery Plan (DRP) finds that the abundance of barking owls in NSW is declining. It lists threatening processes for the owl, but admits that the key factors (if any) currently limiting the owl's recovery are not entirely certain.

It may be suggested, therefore, that a major cause of this species' decline has to be that in preparation of an EIS and SIS, proponents in every case of a proposed development can present a conclusion that "plenty of similar habitat exists in the area," without having to map the actual habitat, and without having to research the numbers of birds successfully utilising that habitat.

This SIS in no different.

The DRP finds by surveys that barking owl has declined to a point where it is now absent or rare in areas where it used to be seen regularly in past decades, and that it would be wise to assume that any nesting failure and mortality of the owl has to be significant. Hence, at a local level, it is necessary to protect breeding pairs and nest sites. Yet if this SIS is approved there will be no opportunity for identification of nesting sites, let alone their protection.

Neither CE for the SIS, nor Greenloaning Biostudies during monitoring surveys, made any attempt to identify nesting sites for barking owl. Similarly, during the owls' 2002 breeding season, surveyors in the employ of the proponents were regularly at work in the forests of Lot 119/59, clearing tracks and even removing threatened flora species for their theodolite sighting lines, and for vehicle access. At least one old stag came down in this process, and at least one, possibly two pairs of barking owl could quite possibly have been disturbed too frequently by this activity to complete a successful breeding season. That if their nesting hollow wasn't removed entirely. No studies for this species was carried out before the surveyors commenced their work.

This will be the same scenario if the SIS, and consequently the proposed access road alignment, are approved.


Within its home territory, barking owl requires thickly forested habitat, rainforest and riverine woodland for daytime roosting; nesting hollows for breeding, and woodland and open country for hunting. Its hunting territory requires a minimum of 200ha (Taylor et al 2002) to over 6,000ha (Schedvin et al 2001). This is considerably more than stated by NPWS' (2002), where the finding is that a barking owl's territory ranges from 30ha to over 1,000ha. This lesser estimate stems from an earlier report by Blakers et al (1984).

Despite the upward revision, Cumberland Ecology (CE) for the Species Impact Statement (2005) prefers to quote the NPWS' version of habitat requirements for barking owl.

Table 2.2 (p2.6) of the Compensatory Habitat Plan of Management suggests there are 756ha of foraging habitat protected for barking owl, with some potential for roosting and nesting. By this it must be concluded there are few hollows for nesting barking owls.

In fact this is the case. Along the southern headwaters of the Black Swamp wetland the terrain rises steeply on all sides, to become dry, relatively sparsely vegetated sandstone ridges and cliffs. The woodlands along these ridges support older trees with many hollows and 'pipes' that provide habitat for prey species and suitable hunting grounds for barking owl. However, as the majority of the dominant trees are not large, there are few hollows suitable for roosting and breeding purposes for large forest owls.

Vol B, p6.2, finds the frequency of hollows within lowland forest and woodland areas to be medium to low. This forest type includes the natural bushland across joint lots 119/59, owned by Clarence Valley Council, which is possibly prime habitat for barking owl. This tract of forest contains approximately 2km of tall old-growth eucalypts along significant disused Crown road reserves (soon to be closed?); large areas of forest red gum-dominated communities (a species not favoured by the timber industry), and two disconnected Melaleuca swampland corridors along Perennial Creek and the drainage line to the east through Lot 2 Shannondale Estate. Neither of these waterways have been impacted by cattle, while patches of Lantana occur only in small irregular patches along Perennial Creek. These swampy creeks and the Black Swamp wetland provide a permanent water source for the many fauna species that inhabit the area, including prey species for the barking owl.

This aspect of a secure water supply for small, relatively immobile prey species has not been considered by CE in preparation of the SIS and 8-part test for barking owl.

Similarly the proposal to clear a total of 74 old stags; 112 maturing replacement trees, and 25 old growth trees with large hollows for the access road has been addressed only in terms of a suggestion that the alignment has been altered to avoid such impact.

(*Note, this alignment has been altered back again, to a preferred and more practical straight line through the forest - pers ob Edwards 2005)

The Phytophthora cinnamomi Plan of Management Table 3.6 (p3.18) finds there are no confirmed records of barking owl in the study area, despite video evidence and official lodgment (Edwards & Edwards 2002). By its apparent absence the chance of impact by Phytophthora is deemed to be low. With current knowledge of the species' presence in the area, this should require some further assessment.

The Shannon Creek Restoration Plan (Table 5.1) is better informed, finding the barking owl to be known in the area, with a habitat preference for swamp, dry forest and woodland. Its key habitat and food resource requirements involve hollows and large hollow-bearing trees, with an understorey of Allocasuarina littoralis or torulosa and Acacia species for roosting and foraging sites. This plan finds that areas downstream of the dam site has ample roost sites but not many hollows, and a very limited number of large hollows; the cleared areas have occasional occurrences of both roost and hollows, and the escarpment is mainly considered all right, although still with limited hollows (p6.1)

The Species Profile (Vol 3, p3.57) states that barking owl is known to occupy eucalypt forest, open woodland, swamp woodland and timbered watercourses: which knowledge makes a mockery of the map presented at the end of the profile as suitable habitat for barking owl

The Species Profile (Vol 3, p3.60) admits that suitable nesting habitat for barking owl, primarily large old growth blackbutt, exists within sector 3 of the proposed access road . P3.61 claims that the road alignment has been altered to avoid impacts on these significant habitat trees. This is not correct. The alignment was altered by early surveys, but the new alignment was impractical and has since been returned, as predicted (Edwards 2004) to a more direct alignment.

This same section (Vol 3, p3.60) indicates that as much as 87ha of river oak riparian forest will remain once work is completed. The maps show this habitat to be considerably broader along the creek than it in fact is, and is a grave over-estimation of this significant habitat community to remain. 6.4km of important riparian she-oak vegetation will be inundated by the dam, and a further 1.13km to the north of the wall will be disturbed by constant noisy activity. This leaves approximately 1.13km of she-oak roosting habitat to the north, including a small section on private property (Frank Kelly). Ariel maps show that at the very most 1.3km of river oak riparian might remain above the proposed inundation zone. (See page 4)

This needs to be re-assessed, with a properly identified section of riparian river oak vegetation that will eventually remain along Shannon Creek.

Table 3.11 (p3.61) shows that 38.85ha of riparian river oak, Community #4, will be cleared for the various project components, not just 38ha as claimed. However Activity F7, workers' compound, has been left out of this equation, because there will be no clearing (as such) of the riparian zone for this action. Nevertheless, the long-term effects by disturbance of this valley loop, by becoming a hive of activity during the dam construction phase, criss-crossed with tracks and possibly sheeted (bitumened?) needs to be considered an added significant long-term impact on this section of roosting habitat. There is also no consideration of Activity F7 removing any foraging and nesting habitat at all, yet these habitat types are present within this valley loop.

There are also regular claims that "...the majority of habitat or potential habitat that will not be cleared will be retained and conserved and such areas are extensive, therefore no significant indirect negative impacts are anticipated for barking owl..." (in this case the Species Profile Vol 3, p3.62). This section then admits to 6 potential indirect impacts, and one major key threatening process (fragmentation and clearing of habitat for barking owl), but this doesn't matter because the largest impact will be in the vicinity of the inundation zone where the most significant habitat areas have already been fragmented by clearance for livestock grazing!

Yet this river oak riparian zone is conceded to be an important roosting habitat for barking owl, and the only records in Shannon Creek have been in the vicinity of the vegetation community.

There is also a suggestion that Powerful Owl may start competing with barking owl along the forested upper reaches of Shannon Creek once the dam is filled (p3.63)

The 8-Part test (Vols A, B & C, pB.139)

Although a SIS is required by the TSC Act to present suggested alternatives to threatening actions, CE by this SIS finds only that destruction of the only known habitat for barking owl is not about to impact the population. There is no suggestion to the proponents that this clearly significant barking owl habitat, and habitat for its prey species, should be protected in perpetuity, but rather CE indicates the species' requirement for an extremely large territory to be a benefit.

In point of fact the opposite should be found to be case. Any compaction of an owls' home range by clearing and development must deplete the populations' sustenance requirements in some way. Owls do not claim large territories out of greed, but out of need. The fact that the diverse Shannon Creek forest communities appear to support just one pair, or at most two pairs of breeding birds must indicate that these entire forested lands surrounding and adjacent to Shannon Creek are necessary to these birds' survival.

Part (a), rather than voicing concern about the species' tenuous situation, and although the recovery plan finds that ideally all habitat in NSW will be protected and conserved until this species is on the road to recovery, CE finds that, given the large home-range of barking owl; its broad prey base, and its ability to nest in open county, it is unlikely that (any aspect of) the proposal will affect the viability of the barking owl, therefore no disruption to its life cycle will occur.

If CE's conclusion was correct, then by the claimed large range of "potential" habitat across the region, barking owls should be common throughout this region, not hindered by any of the threatening processes described by NPWS and the NSW Scientific Committee.

Presumably this "potential" habitat is for foraging purposes only. There is little in the way of available old-growth nesting hollows for barking owl on rural subdivided properties.

Part (c) - whether a significant area of known habitat is to be removed - this question is circumvented with the comment that a high proportion of eucalypt forest and woodland will remain. This is not a satisfactory response to the question. The operative word is 'known' (habitat). Barking owl is known only from 2 records in Shannon Creek, both areas of which are proposed to be inundated. With a 'significant' proportion of river-oak riparian forest to be destroyed, and/or otherwise impacted in the long term, this does in fact equate to a considerable amount of known habitat to be removed.

In studies for Black Bittern it is indicated by the The Threatened Species Plan of Management (Table 3.1) that from 22.2ha of riparian river-oak habitat, 17.6ha will be lost to inundation. This same table also suggests that 20.7% of this habitat type will be retained and managed for conser-vation (for black bittern). 20.7% of 22.2ha equates to just 4.6ha of river oak habitat to remain.

The owls have yet to be identified within either the Chambigne Nature Reserve, the buffer zone, or the proposed compensatory habitat.

The NSW Scientific Committee found that barking owl has declined in numbers, declined in

habitat, and has a low reproduction rate, so will become endangered in New South Wales unless factors threatening its survival or evolutionary development cease to operate. As the owl is at threat from clearing of woodland and dry open forest vegetation, particularly large hollow-bearing trees, this proposed regional water supply project and its attendant infrastructure components are doing nothing to cease operation of threatening factors for barking owl.

By the proposed access road alone a total of 74 old stags; 112 maturing replacement trees and 25 old growth trees with large hollows are to be cleared for the road. (GIS id's attached)

Therefore the test fails in this part

Part (e) - whether the species is adequately represented in conservation reserves - finds that the species has not been identified within conservation reserves in the local area, and - in support of NPWS' clear notation (2002) - accepts that preferred habitat for barking owl (ie woodland along water-courses) is poorly represented in conservation reserves.

The test fails in this part


The conclusion by the 8-part test is that although known habitat for a pair of barking owl will be removed, broad areas of habitat sufficient to maintain the species are to be retained in the study area, therefore all components of the dam construction and inundation are unlikely to have an impact on the barking owl.

It has been demonstrated above that habitat remaining in the Shannon Creek vicinity will be largely unsuitable to barking owl, at least for other than foraging purposes.

The failure of the 8-part test in at least 2 parts, and an unsatisfactory response to one other part, should raise concerns about the future long-term security of barking owls in Shannon Creek.

This SIS fails in its necessary requirement to suggest alternatives to impactful proposals, which in this case should include :

The SIS also fails to suggest any worthwhile plans to ameliorate the impacts on barking owl. Ie :

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5 Patricia Edwards (2005), Scientific Licence No S11209