The November 2000 count was undertaken on 10, 11 and 12 November 2000. This is, at the beginning of the lychee season and before the applicant undertook the count of flying fox carcasses at the Farm.
75 The respondents challenge the accuracy of the surveys of which Ms Whybird gave evidence. Francis Dominic Fanning ("Mr Fanning") is an environmental consultant called to give evidence by the respondent. Mr Fanning does not profess expertise in respect of flying foxes. However, he does have an interest in the development of methods for environmental survey. Mr Fanning expressed the opinion "on the basis of the information I have seen, that there are no scientifically valid or verifiable estimates of the population size or total abundance of the Spectacled Flying Fox…". The information seen by Mr Fanning I understand to have been the paper by Garnett, Whybird and Spencer (1999) referred to in [88] below and a report on the census of Spectacled Flying Foxes of November 1999 prepared by Stephen Garnett and Ms Whybird. Mr Fanning drew attention to issues of concern with respect to the accuracy of the surveys identified in the papers to which he referred. Mr Fanning further expressed the opinion that:
"Given the lack of scientific rigour in estimating the current total population of Spectacled Flying Foxes, and the lack of any estimate of the 'local' population, it is not possible to assert with any certainty that the mortalities of Spectacled Flying Foxes at the lychee farm at Dallachy Creek, Kennedy in Queensland could or would lead to that species becoming endangered. Nor does the current evidence provide the necessary scientifically valid basis for concluding that there has been a dramatic reduction in the population of the Spectacled Flying Fox."
76 Christopher Richard Tidemann (Dr Tidemann") is a Senior Lecturer, School of Resource Management and Environmental Science, Australian National University. He was also called to give evidence by the respondents. Dr Tidemann's only knowledge of the population of Spectacled Flying Foxes came from the report on the census of Spectacled Flying Foxes of November 1999 prepared by Stephen Garnett and Ms Whybird. Dr Tidemann stated that, to the best of his knowledge, there is no accurate information on the status of the Spectacled Flying Fox in the World Heritage Wet Tropics Area in the Cardwell Region or elsewhere, other than that contained in the 1999 report of Stephen Garnett and Ms Whybird. He expressed the opinion that:
"Given the uncertainty of the status of the population of Spectacled Flying Foxes in the WTWHA [Wet Tropics World Heritage Area], it is not possible to say, from a scientific perspective, if there is a real risk of extinction of this species in the near future; instead, the species should be viewed as data deficient or insufficiently known until replicate counts have been made under environmental conditions comparable to those under which the base-line counts were made. This applies particularly to any determination of "list status", at international (eg IUCN), national or State level."
77 The methodology adopted in the surveys with which Ms Whybird was involved was not challenged by the witnesses called by the respondents. Rather they drew attention to the inherent difficulties involved in undertaking such surveys.
78 It appears that neither Mr Fanning nor Dr Tidemann had regard, prior to his giving evidence, to the report prepared by Ms Whybird on the November 2000 survey of Spectacled Flying Foxes. This survey is, in my view, of importance not only because it is the most recent survey but also because it involved a replication of earlier surveys involving as it did the use of the same methods as had been used in the earlier surveys with which Ms Whybird had been involved.
79 I accept, as indeed did Ms Whybird, that inherent difficulties exist in conducting a population survey of flying foxes. However, I was impressed with Ms Whybird's evidence generally. She has a particular expertise with respect to Spectacled Flying Foxes. She has been undertaking research on this species for seven years. Moreover, the evidence before me reveals that she is an acknowledged expert on the topic of the Australian population of Spectacled Flying Foxes. The reports which she has authored or co-authored frankly acknowledge the difficulties in establishing an accurate Spectacled Flying Fox population. However, in her report on the November 2000 Spectacled Flying Fox survey, Ms Whybird stated:
"We are confident that more than 80% of bats were located …."
80 I am willing to accept that Ms Whybird's confidence in the accuracy of the November 2000 survey is well placed. In my view, for present purposes, Ms Whybird's expertise and relevant experience is adequate to compensate for the theoretical difficulties which stand in the way of complete scientific rigour in estimating the total Australian population of Spectacled Flying Foxes. The Court is not concerned with whether the applicant has established with complete scientific rigour the total Australian population of Spectacled Flying Foxes. The duty of the Court under s 140 of the Evidence Act is to determine whether the case of the applicant has been proved on the balance of probabilities.
81 I conclude that, as at early November 2000, it is more likely than not that the total Australian population of Spectacled Flying Foxes did not exceed 100,000.
82 Ms Whybird gave evidence that of the roughly 80,000 Spectacled Flying Foxes counted in November 2000, only 10,410 were counted within fifty kilometres of the Farm. However, she rejected the suggestion that this figure meant that it was impossible that more than 28,000 (ie one possible extrapolation from the applicant's counts) Spectacled Flying Foxes visited the Farm during the 2000-2001 lychee season. She did, however, suggest that the figure of 28,000 was too high. She rejected the suggestion that a figure of about 15,000 was "highly improbable". She referred to the "vacuum effect" of which Mr Richards also gave evidence.
83 In his oral evidence Mr Richards said:
"It is not easy to say whether one grid, or one farm will contribute totally to the extinction of the animal, but there is also the vacuum effect with these sorts of systems and that is my worry. A major impact has a vacuum effect, rather than a randomised effect of, for example, colliding with power lines or motor vehicles."
When asked to explain what he meant by "vacuum effect" Mr Richards said:
"In a lot of animal populations if you are trying to control them - for example, if you poison animals that have established territories, those that have been kept out of the territory by the ones pre-poisoning, there's a balance. But if you take out a group that maintain territorial boundaries, for example, then others break their boundaries and move in. And that's called a vacuum effect.
…
Sorry, your Honour, I was trying to suggest that one grid as it kills animals can keep killing animals. It's not as if there's a discrete number in an area to kill, because these animals are very, very mobile, and this sort of method of orchard control has the potential to just keep killing animals as they discover the orchard and attempt to feed in it, and it just becomes like a vacuum going down the bath plug."
84 To the same effect was the evidence of Dr Martin who in his report stated:
"Flying Foxes like P. conspicillatus routinely forage over 50km per night. If there is a good food source, individuals will increasingly move from distant roost sites to ones closer to that food source. Similarly, if there is a good food source and bats from a local roost are being killed, bats from more distant areas will move into vacancies in that roost. Thus, to the grower killing the animals, there will be a perception of "millions" of animals - a never-ending supply - and a misconception that the animals breed like rats and mice. The ecological technical term for such movement into a cull site is "source-sink dispersal" (Pulliam, 1996); the site of culling is the "sink" into which animals move from surrounding "source" areas. Not only will any orchard culling of a perceived "local" population fail to eradicate attacks upon the orchard, but the slaughter will produce a vacant niche, a pteropucidal black hole which will drag animals into it from far afield. The image of a black hole and its irresistible gravitational force sweeping every-thing [sic] into its maw is, I believe, a not unreasonable metaphor. Not only will this particular orchard culling fail to eradicate attacks upon the orchard, because of replacement of bats, but the slaughter will produce the local vacant niche, which will then become occupied by animals moving into it from further afield, which are then killed, so producing a local vacant niche which then…and so on.
…It seems self-evident that the culling of P.conspicillatus in the Bosworth orchard will affect populations over a broad span of the surrounding Wet Tropics World Heritage Area."
85 I do not understand the respondents to have challenged the notion of the "vacuum effect" or its relevance to the issue of the impact of the Grid on the Spectacled Flying Fox population. In any event, I see no reason to reject the evidence of Mr Richards, Dr Martin and to the extent that Ms Whybird also gave such evidence, Ms Whybird, concerning the vacuum effect and its significance in respect of the operation of the Grid.
86 Another matter of significance so far as the issue of the impact of the Grid on the population of Spectacled Flying Foxes is concerned, is that, as a number of witnesses said, and I accept, the Spectacled Flying Fox is incapable of rapid reproduction. Dr Martin gave evidence that females do not usually complete a pregnancy successfully until they are in their third year and they bear only one young per year. Although Spectacled Flying Foxes have apparently lived for more than twenty years in captivity, I accept the opinion of Dr Martin that the present "natural" longevity in the wild is possibly much less, being approximately ten to fifteen years. Dr Martin stated in his report:
"Such an evolved breeding strategy is successful only if animals are long-lived and suffer low mortality rates. Any imposed mortality has severe effects on population size." (emphasis in original)
87 Dr Martin expressed the unchallenged opinion in his report that "in the face of habitat destruction, natural stochastic events and direct exploitation by humans" baseline mortality rates for flying foxes in the range of 20% - 30% was realistic. He further expressed the unchallenged opinion that fecundity rates as low as 70% - 75% are not unreasonable. Dr Martin went on to express the opinion, which was again unchallenged, that:
"In contrast to deaths imposed by shooting, stochastic disaster, or intentional electrocution, most 'natural' deaths are likely to be unperceived. In relation to actual and perceived death-rates any perceived 'human-imposed' death-rate would have an additive effect on the unperceived 'natural' death-rate. This means that a perceived imposed death-rate of 10% per annum by intentional electrocution, or other form of culling, adding to an unperceived natural death rate of 10% will produce a total death-rate of approximately 20% and, given an adult fecundity of 90%, the population will remain close to stasis. At this fecundity, any imposed death-rate greater than 12% will cause population decline. If adult fecundity is below 90% and unperceived 'natural' death-rate is higher than 10%, any imposed-mortality leads to greater and greater population declines. So, with a 'natural' death-rate of 20% and adult fecundity of 80%, an imposed mortality of 10% will lead to a halving of the population in less than five years. On the basis of these relationships one can calculate the effects of a known harvesting rate on a population of any given size." (emphasis in original)
I understand Dr Martin in the above passage from his report when referring to "an imposed-mortality of 10%" to mean an imposed mortality of 10% of adult female flying foxes.
88 On the basis of my above finding that the total Australian population of Spectacled Flying Foxes in early November 2000 did not exceed 100,000, I conclude that the total population of adult female Spectacled Flying Foxes was approximately 50,000. In reaching this conclusion I note that Dr Martin in oral evidence was prepared to assume that female flying foxes constituted roughly half the population. When questioned by me as to this assumption, Dr Martin said that at birth there was a balance between male and female flying foxes although "[l]ater on there are questions." Neither Dr Martin's cross-examination nor his re-examination resulted in these questions being identified. I further note that it was put to Ms Whybird in cross-examination that, in effect, females would constitute half the Spectacled Flying Fox population. She did not demur from this proposition and the issue was not explored in her re-examination. There is in evidence an article published in the Australian Zoologist of June 1999 of which the authors were Garnett, Whybird and Spencer. The article contains the assertion that "there is a ratio of at least 2:1 in favour of females in Spectacled Flying Foxes". However, neither Ms Whybird nor any other witness was asked to comment on the accuracy of this assertion. I consider it appropriate in the circumstances to rely on the way in which the proceeding was conducted and on the oral evidence of Dr Martin and, to the limited extent mentioned, Ms Whybird, on the issue of the proportion of the Spectacled Flying Fox population likely to be female.
89 On the basis that the total adult female Spectacled Flying Fox population in early November 2000 was approximately 50,000, on my above findings roughly 20% of that population was killed by the Grid during the 2000-2001 lychee season.
90 It was submitted by the respondents that, in determining whether the operation of the Grid had or will have a "significant" impact on the world heritage values of the Wet Tropics World Heritage Area, it is impossible to look at the impact of the Grid in isolation. They argued that it is necessary to weigh the impact of the Grid as one component only of the overall threat to the Spectacled Flying Fox. The first point to be made in respect of that submission is that the evidence before me as to the impact of other threats to Spectacled Flying Foxes is sparse in the extreme.
91 There is evidence that at the time that the Garnett, Whybird and Spencer paper referred to above was written (ie mid 1998), permits for ten electric grids within the range of the Spectacled Flying Fox had been granted, and that a number of grids was thought to be operating without permits. The paper indicates that the reported number of deaths from the operation of the grids was only 856. Even if it be accepted that the reports were likely to be an underestimate, the impact in late 2000 of the impact on Spectacled Flying Foxes of electric grids for which permits had been granted in 1998 can only be a matter of speculation. Amongst other possible factors, the Act itself, which only came into operation on 16 July 2000, may have had an impact on the number of grids being operated for the purpose of killing flying foxes.
92 Graham David Minifie ("Mr Minifie"), General Manager of a company which provides protective canopy systems for orchards, gave evidence of seeing grids on other properties when he travelled to the Farm in mid-2001. However, the Grid was the largest grid seen by Mr Minifie. Mr Minifie's evidence suggested that there is presently a tendency for grids to be replaced by canopy systems. He said:
"Nearly every lychee property I was quoting on they had previously an electric grid system."
93 Moreover, Mr Minifie described the respondents' lychee orchard as "extremely large". There is no evidence to suggest that any other electric grid approximating the scale of the Grid was operating in November 2000 or has operated at any time thereafter.
94 Similarly, although I accept that Spectacled Flying Foxes are shot by farmers, there is little evidence before me as to the scale of such shooting. The Garnett, Whybird and Spencer paper reported that in 1997 a total of 1,202 flying foxes were shot under permit by twelve farmers. The paper recognised the unreliability of the figure but pointed out that "shooting takes exceptional diligence, accuracy and sleeplessness to be effective." Again there is no evidence before me on which I could conclude that Spectacled Flying Foxes were being shot in numbers which even approach the numbers that were killed by the Grid in the 2000-2001 lychee season.
95 Similarly such evidence as there is as to Spectacled Flying Foxes being killed by power transmission lines, cars and even ticks, suggests that the numbers are not great. Although habitat clearance is, no doubt, an important issue, the listing of the Wet Tropics World Heritage Area on the World Heritage List in 1988 may be assumed to have significantly limited habitat clearance. No evidence was called of any cyclone or other national disasters likely to have impacted on the Spectacled Flying Fox population in late 2000 or early 2001. Further, I accept the logic of Dr Martin's evidence that:
"mortality rates are additive so that if you have a population of flying foxes which has an existing mortality, that animals are dying at such and such a rate per year due to habitat clearance, due to shooting etcetera, due to other electrocutions, you can add on to that mortality the mortality provided by the electrocution in this one orchard. They are additives so they are not really taken in isolation. …
…if you have a population which is already experiencing a mortality which might be described as natural, you can add on and you can calculate the actual additional size of the population that is put at risk by what is happening in this one orchard."
96 I turn to consider whether the killing of Spectacled Flying Foxes in the numbers identified above, has, or will have, or is likely to have a significant impact on the world heritage values of the Wet Tropics World Heritage Area within the meaning of s 12 of the Act.
97 It was contended by the respondents that "likely" in the context of par 12(1)(b) of the Act means probable in the sense of more likely than not. I have not found it necessary to reach a concluded view on the accuracy of this contention. However, I incline to the view that a lower standard is intended to be set by par 12(1)(b). As Bowen CJ pointed out in Tilmanns Butcheries Pty Ltd v Australasian Meat Industry Employees' Union (1979) 42 FLR 331 at 339:
"The word 'likely' is one which has various shades of meaning. It may mean 'probable' in the sense of 'more probable than not' - 'more than a fifty per cent chance'. It may mean 'material risk' as seen by a reasonable man 'such as might happen'. It may mean 'some possibility' - more than a remote or bare chance. Or, it may mean that the conduct engaged in is inherently of such a character that it would ordinarily cause the effect specified."
In the same case at 346 Deane J observed:
"The word 'likely' can, in some contexts, mean 'probably' in the sense in which that word is commonly used by lawyers and laymen, that is to say, more likely than not or more than a fifty per cent chance ('an odds-on-chance', per Lord Hodson in Koufos v C. Czarnikow Ltd [1969] 1 AC 350 at 410) …. It can also, in an appropriate context, refer to a real or not remote chance or possibility regardless of whether it is less or more than fifty per cent. When used with the latter meaning in a phrase which is descriptive of conduct, the word is equivalent to 'prone', 'with a propensity' or 'liable'."
98 It might well be thought that it would be consistent with the objects of the Act, as identified in s 3 of the Act, for the expression "likely" in par 12(1)(b) to be understood in the sense of "prone", "with a propensity" or "liable". Such an approach would be consistent with the "precautionary principle" which informs much environmental protection and conservation work (see the discussion of Sackville J of the "precautionary principle" in Friends of Hinchinbrook Society Inc v Minister for Environment (1997) 142 ALR 632 at 677-679). It would consequently tend to avoid the risk to biological diversity and the environment generally which would flow from the need for scientific certainty or confidence about the potential impacts of actions concerning which there has been limited scientific study. However, as already mentioned, it is unnecessary in this proceeding for me to give this issue further consideration. Further, it is undesirable that I do so as no party addressed submissions to the Court in support of such an approach.
99 The parties were in broad agreement that in the context of s 12 of the Act a "significant impact" is, as expressed in the applicant's written submissions, an "impact that is important, notable or of consequence having regard to its context or intensity." Reliance was placed on a number of Australian authorities including Oshlack v Richmond River Shire Council and Iron Gates Developments Pty Ltd (1993) 82 LGERA 222 per Stein J at 233; Concord, North Sydney, Woollahra and Manly Councils v Optus Networks Pty Ltd (1996) 90 LGERA 232 per Dunford J at 264: McVeigh v Willarra Pty Ltd (1984) 6 FCR 587 per Toohey, Wilcox and Spender JJ at 596; Tasmanian Conservation Trust Inc v Minister for Resources (1995) 55 FCR 516 per Sackville J at 541; Drummoyne Municipal Council v Roads and Traffic Authority of New South Wales (1989) 67 LGRA 155 per Stein J at 163.
100 It is not clear that the factor of "intensity" has, as such, been identified in the Australian authorities. However, I note that the United States' National Environmental Policy Act, 42 USCS s4321 et seq requires that the issue of whether there may be a significant effect on the environment requires consideration of two broad factors: "context and intensity" (see 40 CFR s1508.27; see also Sierra Club v United States Forest Serv, 843 F.2d 1190, 1193 (9th Cir. 1988); National Parks and Conservation Association v Babbitt 241 F.3d 722, 2001 US App. Lexis 2648).
101 Although, as is indicated above ([67]-[68]), I accept that the Spectacled Flying Fox contributes to the world heritage values of the Wet Tropics World Heritage Area, the evidence is, in my view, insufficient to allow me to be satisfied that even a serious reduction in the numbers of Spectacled Flying Foxes (as opposed to flying foxes generally, or seed dispersal and pollination agents generally) would of itself have, or be likely to have, a significant impact on those aspects of the world heritage values of the Wet Tropics World Heritage Area which relate to the flora of the area.
102 However, as is indicated above ([67]-[68]), I accept that the Spectacled Flying Fox is part of the record of the mixing of the faunas of the Australian and Asian continental plates and that the species constitutes part of the biological diversity for which the Wet Tropics World Heritage Area is a most important and significant natural habitat for in-situ conservation.
103 I am satisfied that the disappearance of the Spectacled Flying Fox from the Wet Tropics World Heritage Area, or an appreciable reduction in the numbers of Spectacled Flying Foxes within the Wet Tropics World Heritage Area, would impact on the world heritage values of the area. Either such event would tend to detract from the biological diversity of the area and from the importance and significance of the habitats contained within it for in situ conservation of biological diversity. Further, I am satisfied that the disappearance of the Spectacled Flying Fox from the Wet Tropics World Heritage Area, or a dramatic reduction in its numbers in the area, would detract from the record contained in that area of the mixing of the faunas of the Australian and Asian continental plates.
104 In my view the finding that the operation of the Grid during the 2000-2001 lychee season had the consequence that approximately 20% of the population of adult female Spectacled Flying Foxes were killed leads inevitably to the conclusion that the operation of the Grid had a significant impact on the population of Spectacled Flying Foxes. Further I find, on the balance of probabilities, that the probable impact of the operation of the Grid, if allowed to continue on an annual basis during future lychee seasons, will be an ongoing dramatic decline in the Spectacled Flying Fox population leading to a halving of the population of Spectacled Flying Foxes in less than five years. The paper by Garnett, Whybird and Spencer indicates that under IUCN criteria a species may be listed as endangered if it has "undergone an observed, estimated, inferred or suspected decline of at least 50%… over the last 10 years or 3 generations whichever is longer". A "generation" for the IUCN criteria is relevantly four years. I therefore conclude on the balance of probabilities that the probable impact of the operation of the Grid, if allowed to continue in the manner mentioned, will be to render the Spectacled Flying Fox an endangered species in the Wet Tropics World Heritage Area and in Australia in less than five years.
105 Is this impact on the population of Spectacled Flying Foxes to be equated in the context of the Act with a significant impact on the world heritage values of the Wet Tropics World Heritage Area? This is an issue on which virtually no authoritative guidance appears to be available. Having regard to the objects of the Act, which include the conservation of biodiversity, and the terms of the World Heritage Convention, which include a recital which emphasises the international recognition of the significance of the "deterioration" of natural heritage (see [113] below), I have concluded that in the circumstances of the present case it is. In this context, in my view, a dramatic decline in the population of a species, so as to render the species endangered, where that species forms a part (other than an inconsequential part) of the record of the Earth's evolutionary history or of the biological diversity of a most important and significant habitat for in-situ conservation of biological diversity is to be understood as having an impact that is important, notable or of consequence. I reject the submission of the respondents that before this conclusion can properly be reached it would have to be established that the Spectacled Flying Fox is itself, when compared with other species, a species of outstanding universal value. In any event, I note that outside of Australia the Spectacled Flying Fox is found only in Papua New Guinea and there only from less than ten locations (see [52`] above). In this context, the loss of the Spectacled Flying Fox from the Wet Tropics World Heritage Area and from Australia would, in my view, be a matter of considerable consequence.
106 I find that the continued operation of the Grid is likely to have a significant impact on the world heritage values of the Wet Tropics World Heritage Area.