• all levels of biodiversity are interconnected, therefore managers should not focus on only one level
  
• ecological boundaries do not follow administrative/political boundaries, so management has to be at the appropriate ecological scale
  
• ecological integrity must be maintained through the conservation of viable indigenous populations, inclusion of natural disturbance and ecosystem representation
  
• data collection is more important in natural forestry systems than the more commercially driven forestry practices which do not attempt ecological sustainability (several more species must be monitored to protect biodiversity)
  
• success or failure needs to be evaluated through monitoring programmes and the results fed back to managers
  
• management has to be flexible or adaptable, continually learning and revamping their practices to capture economic and ecological goals
  

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  ² Grumbine (1994); Perley (1998).

  
  

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• co-operation among all stakeholders is needed to accommodate adequate ecological scales
  
• organisations have to change their old links and ways to meet contemporary ecological management requirements
  
• Humans are part of nature. Both nature and humans affect each other
  

• a hierarchical approach, where sustainable use is based around the integration of ecological, economic and social factors⁴
  
• an intention to cross administrative boundaries where necessary to manage resources at ecological scales
  
• the group-tree-selection concept which is based upon natural disturbance both in time and space
  
• investment in research that has provided them with baseline data
  
• existing monitoring and commissioning of research for new monitoring programmes that will help indicate the health of their forests
  
• assumption of the role of adaptive managers using scientific knowledge to form a feedback loop for their managerial practices
  
• cooperation with local communities and DoC as a matter of policy
  
• implementation of organisational changes to be more environmentally focussed and open to such interest parties as members of environmental groups⁵
  
• a sustainable approach is intermingled with the concept that humans and nature are part of each other.
  

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Go to index.
2.2 Past levels: what is natural and what can we expect if we do nothing?
There are no long-term monitoring programmes in place to quantify recent trends in wildlife abundance in TWC forests, and few elsewhere in New Zealand. The perception that species are sliding further towards the "extinction vortex"⁶ comes from shrinking distributions and anecdotal reports that wildlife abundance was much higher at the end of last century. Several species have already gone from all or most of the TWC beech forests (e.g., kakapo⁷, South Island kokako, South Island brown kiwi, Little Spotted kiwi, South Island bush wren, yellowhead, South Island saddleback, South Island piopio, short-tailed bats, and an unknown number of invertebrate and plant species)⁸. Others persist over wider areas but may be in decline⁹. Habitat removal and/or severe modification undoubtedly contributed to historical declines, especially in distribution (rather than abundance).

However the factors causing initial declines are not necessarily the main threats now. Unfortunately there are signs of ongoing declines for some species even where habitats remain unchanged. A recent (1995) repeat of bird counts done in the 1970s in beech forests at Mt Misery (Nelson Lakes National Park) has detected declines in the abundance of 10 bird species (and increase in one). No habitat modifications have occurred in Nelson Lakes National Park in these intervening years – this is a sober warning of what might happen if preservation of land alone is considered to be a sufficient conservation response.

Unless we intervene soon there is no reason to expect a halt to further degradation of biodiversity in TWC forests.
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2.3        Predation by introduced mammals and wasps: the immediate threat

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Predation is the most urgent problem confronting wildlife conservation in New Zealand. The Department of Conservation considers predation to be a critical threat to 18 of 30 vertebrate species, such as our national symbol the kiwi, that are of highest priority for conservation¹⁰. New Zealand's attempt to protect these species are part of our national¹¹ and international¹² obligations to protecting biodiversity. In the past, conservation managers considered predator control in situ too unreliable, difficult and expensive, so the safest and most effective response was to shift threatened species to offshore islands where the predators did not occur¹³. Now that most of the critically threatened species are secure on offshore islands there has been a shift of emphasis towards restoration of mainland ecological communities. This proposal continues this trend. Ongoing declines of several species suggests that predation will continue to restructure New Zealand's mainland forest communities unless the effective predator control occurs. It is only recently that relatively safe and effective methods of predator control have become available for conservation managers that might allow sustained pest control for restoration of mainland ecological communities. Rats and stoats are the critical predator species in South Island beech forests, especially after beech seeding has triggered population irruptions¹⁴.

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2.4        Securing habitat quality: a basic first step but not sufficient in itself
In the past habitat removal or severe modification has undoubtedly caused declines and endangerment of several species¹⁵. Past unsustainable forestry practices have played their part in this regrettable situation, and strident public debate over clear felling and over-cutting of indigenous forests triggered the genesis of a popular conservation movement in New Zealand¹⁶.

Evidence has been cited that past forestry practices have threatened bird numbers by removing habitat. The past history of logging impacts provides a general precautionary tale. However, use of evidence concerning past methods for predicting impacts of the new approaches embodied in

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this proposal is unbalanced risk assessment. Work by O'Donnell & Dilks (1987) and O'Donnell (1991) is the most relevant of the published record to predict impacts of logging, but there are problems using it in this way to predict outcomes for this proposal, because:

1. the proposal is not to remove the largest live trees or standing dead spars;
   
2. the paper was based on data from a different forest;
   
3. it tests the model by using data from forests heavily modified by historical methods not proposed here;
   
4. Dr E.B. Spurr's data, used for the test of the model, compared forests logged recently c.f. long ago¹⁷. This assumes bird abundance was the same everywhere before logging and that logging was the only important ecological change between areas;
   
5. the predictions of the model worked for yellow-crowned parakeets and yellowhead, but not for kaka (we should have little confidence in any model until its predictions are upheld for a replicated series of species or place, or until a plausible post-hoc hypothesis is tested for why the model should apply to one species and not another);
   
6. the model assumes that the preferences indicated by the bird studies demonstrates need, and so retrieves the over-riding assumption that habitat variables limit the populations. All animals will show preference of some sort or another¹⁸ for particular foods or places, but this does not mean that such preferences have any tangible impact on their numbers¹⁹.
   

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control predators. Nevertheless it is important for long-term minimal risk for biodiversity to not do anything to deteriorate habitat quality in ways that will reduce eventual "carrying capacity" ²¹; once predator and competitor ²² control has restored numbers.
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2.5        The importance of large old trees
The fundamental approach of TWC's proposed timber extraction is to leave the forest structure minimally altered relative to natural variations. Indeed the careful monitoring and matching of timber removals to what is there is designed to "track" natural changes ²³. Nevertheless ecological knowledge emphasises that retaining the visible presence of the forest may not be enough. Critical habitat features, like tree holes and hollows are thought to be potentially important for hole-nesting birds and bats.

Monitoring of tree size and abundance is a critical safety check for biodiversity as forest use unfolds (see Section 5 and Appendix 3). Nevertheless there are already several inferences that holes do not critically limit current abundance of birds or bats. If predation or competition from introduced mammals and wasps suppress the population or is causing an ongoing decline, the population will be below the forest "carrying capacity" set by habitat variables such as food and nest/roost hole availability. There is ample evidence of the pervasive impacts of predation, and these predatory impacts have been operating for well over a century. In such circumstances we would expect the current populations to be very much below carrying capacity set by habitat variables. For example, in the only detailed study of its kind ²⁴, yellowhead were found to have nine times more holes than they needed. During the first four years of this study, yellowhead density was about at carrying capacity, yet it was still not limited by nest site availability, nor through competition for nesting sites with yellow-crowned parakeet. Similarly it was also

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suggested that it was unlikely that nest sites were limiting yellow-crowned parakeet density²⁵. A recent review found no evidence of nest hole competition in New Zealand forests²⁶.

Kaka numbers are also considered to be lowered far below the carrying capacity set by tree hole availability. A Landcare research team found virtually no re-use of the same holes for nesting in their 8 year research programme of kaka at Nelson Lakes National Park²⁷.

Larger trees have more holes²⁸ because of their size and therefore birds can use these larger trees more. It is unlikely that the quality of the holes in larger trees is different²⁹. Therefore, holes in all tree sizes are equally likely to be useable. This is important for predicting harvesting impacts.

The critical question is whether the harvesting proposed will lower the carrying capacity below that which the current populations occur in the face of persistent predation. I think this is very unlikely indeed. Strict testing of trends in overall tree cavity abundance will occur as forestry proceeds provides a check that I am right. In the meantime every inference and available piece of evidence suggests that hole-nesting bird abundance is not currently limited by hole availability, and that there is no threat to this critical habitat element from the proposal.

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2.6        The importance of food supplies for birds
Mistletoe, miro and rata are important food supplies for kereru and honeyeater birds like tui, bellbird and silvereyes³⁰. These species will not be used or changed in abundance by the proposed scheme. The especial effort to leave trees with mistletoe is potentially important since it is being progressively eliminated by possum browsing³¹.

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Rimu is also an important food for birds. Retention of older trees and subsumation of mortality by careful tree selection are the principal ways that this food supply will be safeguarded.

The single greatest predictor of bird abundance in the beech forests involved in this scheme is the availability of the honeydew scale insect ³² and this "keystone" or "critical" ³³ species is not expected to be affected by the low intensity timber extraction regime proposed. This gives me confidence that large scale and long-term changes will not occur from this proposal.

Epiphytes are important for food and shelter and floristic diversity. Extensive epiphyte gardens predominate on the larger older trees. These will be protected by the tree selection protocols that are central to the proposal.

The whole importance of food limitation for forest bird populations is unproven, and even more difficult to evaluate than the hypothesis that tree hole availability limits the population. Evidence for the mechanisms for the effects of past logging methods on bird numbers is almost completely lacking ³⁴. Without this knowledge of mechanisms it is much harder to guess at the likely impact of small group tree removals when the bigger/older trees are left in place. However, the same general argument about the likely impacts of predation apply to the food limitation hypothesis i.e. when severe predation occurs, especially of adults as in the kaka case ³⁵, food is most unlikely to be a limiting factor.

The monitoring and adaptive management approach acts as an overall safeguard for these risks. Similarly, the same large trees left in situ by the group-tree selection protocols to safeguard

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availability of cavities will also help ameliorate potential food impacts because the largest trees are also the favoured feeding trees for many species of bird ³⁶.
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2.7        Fragmentation and roading

On average ca 3 - 4 gaps (maximum of 0.05ha each) will be created per hectare of forest in each harvesting event (every 15 years). Most passerines have territories in the order of a hectare, and bats in the order of 10s of square km, so localised effects are unlikely to be significant. This style of forestry is fundamentally different in that it does not trigger fragmentation of the habitat. The size and intensity of tree removal events is similar to natural levels of gap formation in the forest and artificial gaps replace natural gaps by (the process of subsumation) the tree selection and subsummation of natural mortality process. There will not be a cumulative effect from natural gaps plus artificials. The artificial gaps will replace (subsume) natural gaps that would otherwise form. Canopy cover therefore remains intact. Fragmentation is therefore maintained at broadly natural levels.

Fragmentation is a potential threat by disrupting dispersal between patches of suitable habitat. It also causes an increase in edge habitat compared to cores, and such edges are considered potential sites of intense predation and invasion by weeds. This "ecotone" idea has been promulgated from overseas work. DoC's Eglinton predator research team could find no evidence that stoats concentrated their activity near to roads in 1990/91 and 1992/93, and in 1991/92 traps along roads actually caught significantly fewer stoats³⁷. The only direct test of this "habitat edge" hypothesis in New Zealand so far failed to find any change in probability of predation of yellow-eyed penguin chicks on edges c.f. middle of forest breeding areas³⁸. It may be that New Zealand biota are so vulnerable to predation that any slight concentration of predators on habitat edges is irrelevant (since nestlings in centres are also nearly always eliminated even if there was less predator use of such areas).

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Roads may also benefit biodiversity by allowing cost effective predator controls ³⁹ and are also favoured feeding sites for long-tailed bats ⁴⁰ because they create habitat edges.

Roads also present potential threats to forest communities, through the dispersal of invasive species via road and road traffic⁴¹. Male stoats are thought to use the roadside habitat more often than females⁴² but there has been little research into the effects of roading on New Zealand's ecology⁴³.

In any event, the proposed application reduces requirements for roads by about 10-fold, traffic is infrequent and the roads are narrow. They most certainly do not represent barriers to dispersal in the way large motorways do overseas.
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2.8        Recovery forests: a long-term habitat restoration initiative
The primary way that this proposal will confer benefits on biodiversity will be through predator control. However some small areas of 'recovery forest'⁴⁴ will be restored by silviculture methods directed to recreating more natural forest structures. There is ample evidence that bird abundance is reduced in recovery forests compared to unlogged forests⁴⁵. Active intervention by foresters will speed the restoration for the long-term benefit of regional biodiversity.



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I concur with R. Buckingham⁵⁰ that the proposed harvesting is most unlikely to harm these threatened species in TWC forests. The TWC estate has a high species diversity and bird abundance in some areas. It is important to note that the best areas of habitat in the region were taken into DoC reserves at the time of the West Coast Accord. This creation of reserves to exclude sites of importance for wildlife from harvesting was continued by TWC when preparing these plans ⁵¹ . What remains in areas zoned for harvesting therefore has broadly much lower biodiversity value than the region as a whole. In this way a precautionary approach has already been taken to minimise risks to biodiversity from harvesting⁵².

Go to index.

3.2        Kaka
The threatened status of kaka is well researched, and their low abundance and infrequent success in breeding in the South Island are major causes for concern. Historically and on a very large spatial scale, habitat removal undoubtedly caused declines in the distribution of kaka. However clearfelling or over-cutting is not proposed in this proposal, so it would be a non sequitur to link these historical patterns to predictions of what might happen now.

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A Landcare Research team led by Dr Peter Wilson has tested the hypothesis⁵³ that reduction of honeydew by introduced social wasps reduces kaka breeding rate and/or success through competition⁵⁴. A supplementary feeding experiment, now finished, discounted the competition hypothesis⁵⁵. Instead predation of chicks and sitting adult females at nests by stoats is now considered to be the key threat to South Island kaka⁵⁶. Reduction in numbers by predators means that this species is most unlikely to be limited by food or hole availability. Therefore this proposal will not depress kaka numbers. In fact it may enhance them enough through predator control efforts.
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3.3          Other hole-nesting birds
As for other New Zealand hole nesting bird species, yellow-crowned parakeets (a category C threatened species) are vulnerable to introduced predators⁵⁷. However, yellow-crowned parakeets are relatively more susceptible to stoat predation than most other endemic hole nesting birds⁵⁸. Yellow-crowned parakeets nest later than most other hole nesting forest birds and their breeding season extends into the time when stoats are reaching their highest numbers. Yellow-crowned parakeets nest in holes with only one entrance. The incubating adult is always a female. Therefore nest predators often "trap" and kill the incubating adult female as well as eggs and chicks. This causes a sex-biased death rate due to predation, with fewer females available to re-nest after nest predation. Additionally both the incubating female and older nestlings are highly conspicuous to predators due to their noisy vocalisation during feeding⁵⁹. Loss of adults to predators is usually a catastrophic threat for any New Zealand bird because they tend to be naturally long-lived and slow reproducers⁶⁰.

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Rifleman are thought to have declined in TWC forests⁶¹. I consider the evidence for this decline to be statistically weak⁶², as is also stressed by R. Buckingham⁶³. Nevertheless declines in rifleman have been noted elsewhere in New Zealand, notably on mainland Stewart Island, and in the Granville State Forest, the latter covered by this proposal⁶⁴. Rifleman use very small holes which are super-abundant. Any putative declines are most likely to be driven by predation or competition for insect foods with vespulid wasps, but this is speculation.
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3.4         Kiwi
Great spotted Kiwi are present on some parts of the TWC estate⁶⁵. Like all kiwi species on the mainland they are considered threatened, though Dr J. A. McLennan, who studied the great spotted kiwi for several years, considers them to be the most secure of all the mainland populations⁶⁶. A recent survey of the high altitude ('subalpine') Saxon (Heaphy area) population showed no declines in the population after 10 years since Dr McLennan's initial baseline study there. However there have been no repeated surveys of the lowland great spotted kiwi populations to gauge whether they are stable or declining. Dr McLennan suspects the latter to be more likely and as a rule of thumb suggests that kiwi are holding their own in areas above 4.5 m of annual rainfall (the high altitude and/or rainfall seems to represent a refugia, probably from predator populations). Earlier more widespread distribution within the lower altitude dry beech forest has now disappeared. Dr McLennan cites the low ratio of juvenile to adult kiwi recovered by trained research dogs as evidence of predation⁶⁷. Accordingly we can infer that kiwi on TWC land are limited mainly by predators. Predation is listed in DoC's Kiwi Recovery Plan⁶⁸ as the

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primary threat to be mitigated. The great spotted kiwi studied by Dr McLennan bred every year so there was no evidence of habitat quality limitations. In the absence of other information and the expected impacts of predators, it is safe to assume the same lack of habitat limits occur for great spotted kiwi on TWC land.

Dogs are an occasional threat to kiwi and relatively easy to manage⁶⁹. Proposed policies will ban dogs from all kiwi areas.

There is anecdotal evidence that cyanide paste used by possum harvesters occasionally kills kiwi. Small residues of brodifacoum have been found in North Island brown kiwi, but there is no evidence of direct poisoning by brodifacoum⁷⁰. Kiwi survival has now been monitored through several aerial 1080 poison drops without registering kiwi mortality. Gin trapping by possum hunters kills some adults⁷¹. Survivors are often missing claws and around 7% of the Great spotted kiwi adults caught by Dr McLennan carried this sign, even though the intensity of possum hunting had declined a decade before his study.

The proposal already plans to ban dogs from kiwi areas but I suggest that the above risks will be further avoided or mitigated by one or more of the following additional strategies:⁷²

1. ban possum harvest from kiwi areas;
   
2. insist that victor traps are used instead of gin traps;
   
3. insist that traps and poison pastes are set up "ramps" at least above 35 cm and for preference above 70 cm, to eliminate kiwi (and Weka) by-catch;
   
4. restrict harvesting during the kiwi breeding season (late winter to early summer) in kiwi areas.
   

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from the vicinity of harvesting gangs and so are not in danger of being killed. Direct impact of logging operations will probably be limited to occasional disturbance of nesting and potential loss of the current year's egg or chick. This is most unlikely to impact on the population's viability since the adults are long-lived ⁷⁴.
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3.5        Other bird species
Kereru gains its threatened status mainly from declines in abundance in the top half of the North Island ⁷⁵. There is no suggestion that their numbers are low enough to make them regionally threatened in Westland. Kereru suffer intense predation on the mainland and reach much higher abundance on predator-free offshore islands. Accordingly, predation is likely to be holding numbers well below the habitat's carrying capacity. The proposal involved such slight habitat modification that the prospect of any impact on kereru is an extremely remote possibility unless abundance of rimu (an important food ⁷⁶) is significantly reduced. Kereru breeding success responds rapidly to predator control so prospects for increase populations from the proposed predator control ⁷⁷ programme are good. This could be particularly beneficial for wider biodiversity if their hypothesised critical role in seed dispersal is correct⁷⁸.

Western Weka thrive in highly modified habitats. They are very much more adaptable to habitat change than kiwi. Predation has been a particular problem in attempts to restore North Island weka. The precautions taken to protect kiwi from predation are likely to also protect weka.

New Zealand falcon are naturally rare. Any scenario that predicts that the current proposal would in some way harm them would be entirely speculative. The ecological needs and population trends of this species are not well understood.
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Similarly kea are most unlikely to be affected in any way by the proposal. Rata and dead trees are potentially important food sources for these birds⁷⁹, but are unlikely to be impacted by the proposal.

A localised population of blue ducks occurs in one part of the estate. Since they are closely associated with streams which are very unlikely to be altered⁸⁰, there seems little chance that the proposal will impact on them.
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3.6          Bats
Recent work⁸¹ has highlighted the need for a change of emphasis to increasing concern for South Island long-tailed bats as well as short-tailed bats. Formerly it was the short-tailed bats that were considered most endangered and long-tail bats were considered relatively common. More research of both species is urgently needed to see if the findings in the Eglinton Valley are representative of ecological factors impacting on bats elsewhere. The relative importance of long-tailed bat populations on TWC land compared to surrounding DoC land, or populations elsewhere in South Island, has not been demonstrated nor measured⁸².

Threats to birds are potentially different from those for bats. Very important in this regard is the lack of detailed information one way or the other about the importance of predation on bat numbers. The sparseness and apparent elimination of long-tailed bats from much of the TWC estate, even where no habitat modification has occurred, certainly points to some non-habitat related threat. Predation by introduced mammals is the most likely explanation, but this is speculation. DoC's bat recovery programme⁸³ lists predation by rats, stoats and feral cats as a threat to bats. If they are not vulnerable to predation their populations may be much closer to the carrying capacity set by food availability or roost hole availability than expected for the bird species. Competition for insect prey with prolifically abundant introduced social wasps is potentially very important in honeydew beech forest areas⁸⁴.

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Bats go into torpor for some months of the year and so can not fly away if their roost tree was felled. O'Donnell⁸⁵ records up to 123 bats roosting in one tree at a time. A high proportion of a local social group might then be killed if a key roost tree is felled in winter. However the proposal will not add to this risk because the harvesting replaces natural tree fall (mortality is subsumed because leaning and defoliated trees are selected). There is even some prospect that felling gangs will detect bats in the hollow trees just felled (their contracts stipulate that they must cut up such trees into short lengths to accelerate decomposition) and could be required to report them and where possible mount a "bat rescue" attempt⁸⁶.

A population of long-tailed bats in the Eglinton Valley had at least 3 separate "cryptic" social groups that restricted their roosting to a much smaller area within a very large range⁸⁷. Replicate studies are needed to determine if this is a general pattern for short-tailed bat populations. Large areas of that range may have had no roosting by other social groups, or all might have been used. There is no certainty that the bats could (or could not) move or extend their areas to include new holes nearby. Most importantly, the proposal strives to maintain a large number of holes by various strategies. Had historical coupe clear-felling been proposed, then a risk of destroying or seriously disrupting the roosting area would exist, but this is not proposed⁸⁸. The current proposal represents a significant start towards assessing and potentially mitigating any putative impacts on bats. A formalised model of tree hole availability and the impacts of logging on it will objectively measure these risks long before any putative changes are imposed on the system⁸⁹. The model can also test various mitigation measures, especially ones involving tree selection criteria.

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Short-tailed bats roost hole requirements will probably be different from those of long-tailed bats⁹⁰. However, this evidence is very distinct from any expectation that such holes will be in limited supply, either before or after logging, or in the presence of both bats. There has not yet been an analysis of DoC's wider survey data for both bat species to test whether there are fewer or more bats in heavily cut over or coupe logged sites.

Long-tailed bats in the Eglinton Valley shifted roosts regularly, often at almost daily intervals. This behaviour is markedly different from most other overseas bats studied⁹¹, perhaps in part because tree cavity dwelling bats have received little study until the New Zealand effort. The crucial issue for our present risk analysis is whether or not they need to shift so often amongst such a large number of different holes or do they just prefer to do so. Does the continuous mixing reflect ecological or behavioural needs, or simply preference? It may just reflect a superabundance of holes available⁹². It is not known for sure what effect reduction in number of holes in the roosting zone might have on the bats and whether there the overall area of the roosting zone will simply expand. It was clear from the Eglinton Valley studies that vast areas with abundant tree holes existed within the large foraging range of the social groups.

Twenty-two percent of bat roosts in the Eglinton Valley were in standing dead trees. These were favoured roosting sites. TWC do not propose to remove the largest live trees or standing dead trees or spars⁹³. These standing dead trees will be left in situ, therefore the number of holes present in large standing dead trees should not be greatly affected at TWC sites (e.g. Maruia).

The ultimate safeguard for bat impacts rests on rigorous population monitoring and the adaptive management framework in this proposal. This only allows retrospective assessment of impacts but sensible and extensive measures have been planned by TWC to ensure ongoing abundance of roost sites.

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I urge that consideration be given to long-term repeated surveys of bat abundance in the sustainable use areas, including:

• retention of dead spars
  
• retention of large trees
  
• subsumation of natural mortality ('gap-make' trees would fall soon anyway so risk to torpid bats from trees falling is no greater than would occur anyway).

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Inangahua Working Circle and only scattered records of skink species (Oligosoma infrapunctatum, O. nigriplantare polychroma, O. aff nigriplantare 'Grey Valley" and O. sp. 'Denniston') have been recorded in North Westland. The harvesting regime proposed by TWC should not result in any changes to forest structure or composition that would significantly affect lizard habitat, therefore direct ecological impacts are expected to be negligible⁹⁶. However, lizard populations could conceivably be affected by indirect ecological interactions⁹⁷ if harvesting resulting in changes to ecosystem health and stability⁹⁸. Whitaker (1999) and Buckingham (evidence for this consent hearing) are concerned that possible increased competition and predation pressure from introduced species (such as wasps and mammalian predators) could not be predicted. I can not see how this could occur if harvesters are simply subsuming natural gap formation. The size of gaps and frequency of gap formation should not be greatly different from natural sizes and rates. The canopy would remain intact. It therefore seems most unlikely that changes in predator/prey interactions would occur. Whitaker (1999) considers that mitigative measures are not required for lizards with the proposed harvesting regime but environmental monitoring is necessary to detect changes to the lizard fauna.

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Various methods of direct and indirect poisoning have killed large proportions of tagged predator populations in New Zealand forests⁹⁹, so a growing suite of effective control strategies are becoming available to conservation managers. However, large proportions of native passerines are sometimes poisoned when poison baits are applied and exposed on the ground¹⁰⁰ and few other species have been adequately monitored or long-term studies assessing the overall population impact completed. Risks of poisoning native wildlife can be reduced. Risks of poisoning robins were almost entirely eliminated when poison was contained in bait stations¹⁰¹, and sustained large-scale control of predators (by deploying poison either aerial or in bait, along with trapping) has resulted in the successful recovery of threatened populations such as kokako¹⁰². Extensive research is required before rigorous assessment of the costs and benefits to the native wildlife communities and optimise methods of the predator control strategies can be found. Nevertheless, a positive outcome is very likely.

This proposal will add conservation value to forests by controlling introduced pests as a matter of routine forest stewardship. TWC research has striven to identify a cost-effective method that can be derived by staff on routine visits to forests for their other forestry duties. The proposed method of placing control stations (containing poisons) along the roads improves the cost-effectiveness of control programmes while still remaining very effective at killing predators¹⁰³. It will provide safe and cheap protection of native wildlife over extensive areas of the TWC forestry estate. Research into non-target impacts of these poisoning operations is first being completed before extension and routine application of the method is considered sufficiently safe.

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Until the risks are measured it is difficult to prescribe detailed methods or the scale of control interventions that will be possible.

The secondary poisoning approach researched by TWC generated several subsequent investigations by University and DoC teams in the last few years. This is an example of the way research funded by a proposal like this can bring lasting benefits to other conservation endeavours throughout New Zealand. If this proposal is approved, more such research and practical benefits are likely to accrue for conservation throughout New Zealand. The Foundation for Research, Science and Technology is attempting to foster business investment of this sort through the new Foresight programme and NERF. The TWC effort proposed here is therefore in line with New Zealand government science policy.

TWC now seek the opportunity to capture the benefits from their research to enhance bird (and potentially bat¹⁰⁴) numbers in their on forests. In my opinion the prospects for success are high. Valuable restoration of both common and threatened species is likely.
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4.2        Goal of enhancing biodiversity
New Zealand society wants to maintain representative ecological communities on the mainland, partly to further protect biodiversity but also so people can all freely interact with and enjoy the species that make New Zealand forests part of our national identity. TWC is dedicated to helping perfect and include techniques for pest and predator control aimed at maintaining or even improving our indigenous forest communities. This is a key reason for my overall support for the proposal and my overall conclusion that it should be approved.

The techniques to be applied are derived from several commissioned research projects to find the most effective methods to kill predators, minimise risks to non-target species and design optimum intervention strategies. The overall strategy and planning is outlined in their restoration strategy¹⁰⁵ which involves the following general approaches:

• trials of "multi-predator" control methods using secondary poisoning methods,

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• an initial phase (2-3 years) of research to measure efficacy of killing target predators and risks to non target species. Research is now swinging to the latter emphasis.
• experimental management trials on 2-3 intermediate sized areas once risks to non-targets are considered minimal,
• pulsing of poisons to maintain efficacy and minimise poison deployment,

            -     joint funding with government science providers,

            -     the restoration project should be overseen by a steering committee made up of all stakeholders (Foresters, DoC, Conservation NGOs, research agencies etc),

            -     initial independent audit by conservation scientists after 3 years; and the restoration project be trial for 8 years at least before its overall success is evaluated.

The overall Forest Community Restoration Project aims¹⁰⁶:

. .

To establish and implement methods to protect and enhance biodiversity within honeydew beech forests of northern Westland by minimising the risk of extinction and increasing densities and diversity of indigenous species.

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This long-term goal is realisable by triggering the increase in abundance of extant species and extending the distribution of species now persisting within small areas of the TWC estate through control of introduced mammals, and eventually re-introduction of species previously present which now only exist on the offshore islands or in refuges on the mainland. Conservation of biodiversity includes retention of original ecological processes within the community and ecosystem, not just conservation of the species themselves. Increased abundance of some species may be essential to reinstate natural processes with long-term consequences. For example, enhancement of kereru numbers may trigger increased seed dispersal and reduction of wasps (Vespula spp.) may restore litter invertebrates to re-instate former rates of forest litter

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breakdown; and elimination of browsing pressure could reinstate former rates and directions of plant succession.
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4.3        Practicalities: the enormous magnitude of the challenge to be natural gardeners in perpetuity
Restoration must proceed by expensive and intermittent intervention to kill the introduced predators, browsers and competitors. The key to success is to reframe the traditional role of the conservation manager as solely a passive protectionist in favour of a role as a gardener of near natural systems who constantly weeds out the alien species so that native species can flourish. This will demand innovation to develop new techniques and long-term commitment to constantly intervene because introduced pests are common, widespread and difficult to control over large areas of forest. They breed quickly and disperse widely, so numbers quickly resurge following localised control operations. The current proposal is an excellent example of the necessary change in philosophy that is expected to capture new gains for conservation of biodiversity.
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4.4        Scale of TWC Proposed Restoration Efforts
TWC plans to devote between 5 and 10% of annual net revenue derived from sustainable management of beech forests on research, pest control and monitoring strategies of pest and predator species¹⁰⁷. Possum numbers are to be maintained at medium to low levels throughout its forests. In TWC managed areas identified as "Integrated Management Landscapes" by the Department of Conservation, TWC will work co-operatively with the Department to achieve mutually agreed targets for pest control. Population monitoring of possums, wasps and predators to follow the success of control operations will be undertaken in eastern Paparoas and Station Creek in the Maruia Valley using annual trap-catch surveys, spotlight counts and tracking tunnels¹⁰⁸. Some possum control strategies are known to control rats, mice and stoats and these strategies will be used until other multi-predator control systems are developed. TWC intends investing in predator control research, specifically secondary poisoning¹⁰⁹. Predator usage of undisturbed, natural and harvest gaps will also be monitored in a one-off study¹¹⁰.

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Dr H Moller - Evidence for RC 99/75                                             &nb