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A review of the forest models developed and applied by Timberlands West Coast Ltd (TWCL) and Landcare Research Ltd (LRL) has been carried out. The models were reviewed on the basis of default settings for red beech in the Maruia Working Circle. After identifying the similarities and differences between the two models, a sensitivity analysis was carried out to quantify the impact of any differences on model outputs, in particular stand structure and harvest yield. A sequence of model variants was developed and run, starting with the TWCL default model and ending with the LRL default model. Each variant in the sequence differed in only one factor, thereby allowing quantification of the relative sensitivity of model outputs to that factor. The review focuses on the impact of differences between the models in terms of mathematical formulation, input data and assumptions. However, it excludes any analysis of the appropriateness and relative merit of the different mathematical formulations, input data and underlying assumptions. Although these are important considerations they are beyond the scope of this review. Both models can be categorised as Stand Class Models and use the Stand Table Projection Method to project the growth of a stand by simulating the growth of classes of trees. This is a commonly used approach for modelling, particularly for uneven-aged forests. The differences in mathematical formulation between the LRL model and the TWC model are: 1. Mortality is included in the transition coefficients in the LRL model whereas it is treated as an absolute reduction in the TWCL model. 2. The transition coefficients have a different structure because of different assumptions about the distribution of trees within a size class and the residence time of trees in each class. Incorporating mortality within the transition coefficients rather than as an absolute reduction has a minimal impact on model outputs. The use of LRL transition coefficients, without any other model changes, has a major impact on model outputs. However, once mortality is adjusted to reflect the different coefficients, model outputs for the LRL approach are similar to model outputs for the TWCL approach. Another difference between the models is that the LRL model allows for compensatory growth (Version 1.1) and mortality (Version 2). The model includes functions which allow tree growth rates and mortality to vary in response to changes in stand basal area. Invoking these functions can have a major impact on model outputs. Both models have the same initial tree size distribution. There are minor differences between the tree growth rates and the recruitment rates specified in the two models. These differences have a negligible impact on model outputs. The models (in terms of default settings) differ in the relationship between harvest and mortality. A fundamental assumption of the TWCL model "is that mortality is subsumed into harvest through the careful selection for harvest of trees already prone to direct mortality or mortality by association with dying or falling trees". In contrast, an underlying assumption of the LRL model is that "logging imposes mortality that is largely additional to natural mortality in any one year". These differences have a major impact on model output.

The report comprises four Parts. Part 1 presents an overview of risk analysis and its general application to the management of New Zealand's indigenous fauna and sets out a framework for risk analysis for indigenous fauna with reference to the example analysis for indigenous parrots in Part 3 of the report. Part 2 lists the indigenous vertebrate fauna populations of interest and considers, in general terms, the range of disease agents that need to be covered. A semi-quantitative method for prioritising each population of interest so as to allow an orderly progression of successive risk analyses based on each population's priority ranking is presented. Part 3 is an example evaluation of risk analysis for managing the threat of exotic disease to indigenous parrots (psittacines). Part 4 recommends the use of risk analysis as a standard and appropriate tool for the management of risk of exotic disease to indigenous fauna in New Zealand. The report recommends a number of actions that the Department of Conservation could make to reduce risk of exotic disease to indigenous psittacines in particular and indigenous fauna in general.

The Tahiti flycatcher (Pomarea nigra) is one of several monarch flycatcher species in the Polynesian genus Pomarea, all of which are threatened. The Tahiti flycatcher is currently known from only the western side of Tahiti where, during the 1998-99 season, at least 24 individuals, including 10 pairs, were located in four valleys (Blanvillain 1999). Although ten nests were protected from rats in 1998-99, only three were successful in fledging young. Two of these young apparently disappeared one week after fledging and the third, two months after fledging (Blanvillain 1999). Concern was raised about the possible predation by common myna (Acridotheres tristis), and/or red-vented bulbul (Pycnonotus cafer) on juveniles. In 1999-2000 the Societe d'Ornithologie de Polynesie (MANU) was granted funding for Tahiti flycatcher conservation by the South Pacific Regional Environment Programme (SPREP). During 13-26 September 1999, RP visited Tahiti to advise and help CB with aspects of the programme. This advisory work was funded by the N.Z. Ornithological Congress Trust Board (ICBP). It builds on work by Gaze & Blanvillain (1998) funded by the Pacific Development and Conservation Trust.

The Department of Conservation has assisted the Cook Islands Conservation/Environment Service, and more recently the Takitumu Conservation Area Project, to plan and implement a recovery programme for the endangered endemic forest bird, the kakerori.

There are five toxicants (brodifacoum, bromadialone, coumatetralyl, diphacinone, and flocoumafen) registered for rodent control in New Zealand. They are all anticoagulants and are available in water-resistant bait formulations (i.e. wax coating, wax block, or egg). Several new rodenticide products, which are currently in the process of being developed or registered, including a new anticoagulant difethialone, have also been identified. There are no published data on the relative effectiveness, palatability, or durability of the existing rodenticides for field use under New Zealand conditions. However, relevant published information on laboratory and wild rodents is reviewed. It is concluded that the highest priority should be to assess the four weather resistant, second-generation anticoagulant products (Pestoff® Rodent block, Talon® 50WB, Contrac®, and Baraki®) for palatability, durability, and effectiveness for an island protection situation. Improvements could then be made to the existing products if required with additives to improve palatability or durability, lures to attract rodents, and repellents for non-target insect, lizard and bird species. Trials of an alternative (e.g. cholecalciferol) to the persistent anticoagulants should also be considered for island protection. The most rodent-attractive bait station which also eliminates bird access needs to be determined for the complete island protection system.

The number of humpback sightings and the number of whales recorded in this study suggest a slow increase over the last 10 years, particularly in the last 4 years. The results of this study may have been influenced by a variety of factors, the most important of which may be inconsistent effort. The results presented in this report are broadly consistent with that described by Dawbin (1956). As reported by Dawbin (1956), and found in this study, the northern migration occurs between May and August while the southern occurs from September to December. There is little evidence of a change in migration patterns past the New Zealand coast. The inability to quantify effort is a major limitation with the data and does not make it possible to draw clear conclusions on population size or trends in migration. However, the results are useful in determining the locality and seasonality of humpback whales as they migrate along New Zealand coasts.

In the May 1999 budget, the New Zealand Government announced that an extra $6.6 million over five years would be given to the Department of Conservation to fund an integrated stoat control research programme. Stoats, ferrets and weasels were introduced to New Zealand in the 1880s in an attempt to control rabbits. Although stoats were implicated in the decline of some native bird species soon after their introduction, the extent to which they are still contributing to the decline of native species is only now becoming clear. Their impacts on threatened and endangered birds are of particular concern. Stoat control in New Zealand will have to be ongoing if some endemic species are to survive on the mainland. Currently, stoat control relies largely on labour-intensive trapping and the use of poisoned hen eggs. New, more cost-effective and sustainable approaches to controlling stoats are urgently needed. The extra funding means that there is now a real opportunity for finding cost-effective solutions for managing stoats. A Stoat Technical Advisory Group (composed of experts from the Department of Conservation, Lincoln University and Auckland University) has been established to develop and oversee this new research programme. Funding for the first year is $338,000 with funding increasing in 2000/01 to $1.406 million and for the subsequent three years, $1.631 million, each year.

This report is the first stage in a three-stage development of a Border Control Programme for aquatic plants that have the potential to become ecological weeds in New Zealand. A large number of freshwater aquatic plants have already been introduced and are naturalised in New Zealand, impacting on most waterbodies within this country. There are many additional potential weed species reported as present in New Zealand, but not naturalised, and an even greater number not recorded as introduced here. Some of these species could pose an even greater threat to our aquatic environment than those weeds currently naturalised. A range of tables is presented to illustrate the array of new aquatic species that are already believed to be in New Zealand or that could enter and become established. Possible entry pathways identified in this report include natural spread from wind- and bird-dispersed seed, introduction of ornamental, culinary and medicinal herbs, contaminants in other plants and produce, mislabelled plants, and various types of illegal imports. Existing weed risk assessment models fail to adequately separate aquatic plants with different levels of impact. A new model is presented, tailored to the impacts of aquatic species. Tables are presented to demonstrate the improved system of ranking risks for aquatic plant species. A combination of assessments for weediness and the risk of entry into New Zealand will determine the potential threat of each species, allowing a comparison with existing weed species and other species not yet naturalised or introduced here. The greatest risk is perceived to be posed by some species reported to be present, but not yet naturalised in New Zealand, followed by species not reported here, but traded overseas with the potential to be brought here illegally.

Until recently, the herpetofaunal diversity of the West Coast has remained relatively unexplored. Preliminary protein investigations of West Coast skink material indicated that unrecognised species might be present in the area. To clarify questions relating to the skink species present on the West Coast, a joint DOC/Victoria University study of lizards in the West Coast Conservancy Area has recently been completed. As part of this study, we undertook a taxonomic survey of Oligosoma skinks in the West Coast region, using allozyme (protein) variation as the primary data source. Analyses of allozymes are useful because they can identify reproductively isolated populations where they occur together, even if colour and morphology conceal this diversity, and they have previously allowed significant cryptic diversity to be revealed within New Zealand reptiles (for example, Daugherty et al. 1990a; 1990b; 1994; Hitchmough 1997). The allozyme data revealed the existence of three undescribed taxa, which we have labelled: O. "Big Bay", O . " Grey Valley" and O . " Open Bay Islands". O. "Open Bay Islands" remains undescribed due to a lack of collected material from this species. The other two species are being formally described in a paper to be submitted to the New Zealand Journal of Zoology. Discovery of new species of lizards is nothing new. The number of lizard species recognised in New Zealand has increased significantly in the last 45 years. In 1955, McCann recognised 28 species of lizards here in 1994, 59 species were recognised (Daugherty et al., 1994), and by 1999, that number has increased further to over 60 described species, with more than ten other species still undescribed. This increase has occurred clue to the finds of observant field workers and members of the public who continue to discover animals in "out of the way" places, and to the application of new genetic techniques to investigate geographic variation. Species newly discovered in the last 20 years include obvious new species such as Hoplodactylus rakiuriae (Thomas 1981) and O. longipes (Patterson, 1997), and cryptic species that are highly similar in morphology, such as O. maccanni and O. inconspicuum (Patterson & Daugherty 1990).

There were 195 specimens returned from 19 separate fishing trips with onboard observers, between 1 January and 30 September 1998, where birds were killed as a bycatch to various forms of fishing practice. Four of these trips contributed 82% of the birds returned. These autopsies were undertaken for the Department of Conservation as CSL Contract 98/3091. All costs of labelling and packaging, importation under the Biosecurity Act, transportation from Port of Landing to Wellington by refrigerated truck, cold storage, and autopsy facilities were met by the Conservation Services Levy. In 1998 these birds were received from trawlers, domestic tuna longliners, joint venture tuna longliners, and domestic bottom longliners (Tables 1-4). The number of specimens returned for autopsy does not in any way indicate probable catch rates for differing classes of vessel or fishing method, as the observer coverage was not equally distributed throughout the fishing effort. Specific catch locations for the specimens returned are not provided here on the grounds of commercial sensitivity as required by the Ministry of Fisheries and some parts of the fishing industry. However, the maps (Figures 1-5) provide the general location of catches and species returned for the period covered by this report. The distribution shown does not imply any relationship with fishing effort or method as indicated above.