Rozprawy doktorskie: „New Zealand population”

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McKenzie, Jane, i janemckenzie@malpage com. "Population demographics of New Zealand fur seals (Arctocephalus forsteri)". La Trobe University. Zoology Department, School of Life Sciences, 2006. http://www.lib.latrobe.edu.au./thesis/public/adt-LTU20080509.121141.

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Assessment of trophic interactions between increasing populations of New Zealand fur seals (Arctocephalus forsteri) and fisheries in southern Australia is limited due to a lack of species specific demographic data and an understanding of the factors influencing population growth. To establish species specific demographic parameters a cross-sectional sample of New Zealand fur seal females (330) and males (100) were caught and individually-marked on Kangaroo Island, South Australia between 2000 and 2003. The seals were aged through examination of a postcanine tooth, which was removed from each animal to investigate age-specific life-history parameters. Annual formation of cementum layers was confirmed and accuracy in age estimation was determined by examination of teeth removed from individuals of known-age. Indirect methods of assessing reproductive maturity based on mammary teat characteristics indicated that females first gave birth between 4-8 years of age, with an average age at reproductive maturity of 5 years. Among reproductively mature females, age-specific reproductive rates increased rapidly between 4-7 years of age, reaching maximum rates of 70-81% between 8-13 years, and gradually decreased in older females. No females older than 22 years were recorded to pup. Age of first territory tenure in males ranged from 8-10 years. The oldest female and male were 25 and 19 years old, respectively. Post-weaning growth in females was monophasic, characterised by high growth rates in length and mass during the juvenile growth stage, followed by a gradual decline in growth rates after reproductive maturity. In contrast, growth in males was biphasic and displayed a secondary growth spurt in both length and mass, which coincided with sexual and social maturation, followed by a rapid decline in growth rates. Age-specific survival rates were high (0.823-0.953) among prime-age females (8-13 yrs of age) and declined in older females. Relative change in annual pup production was strongly correlated with reproductive rates of prime-age females and adult female survival between breeding seasons.

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Lamoureaux, S. L. "Demography and population models for Hieracium Pilosella in New Zealand". Thesis, University of Canterbury. Plant and Microbial Sciences, 1998. http://hdl.handle.net/10092/4866.

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Hieracium pilosella has become a major concern in the high country grasslands of New Zealand. This thesis provides an understanding of the population dynamics of H. pilosella in an area which has supported the weed as a major component of the vegetation for more than 30 years. The study uses a combined modelling and experimental approach to determine vital rates and regulatory mechanisms. It then uses these to predict the rate of spatial spread, change in density, and the likely impact of biological control. Mature populations of H pilosella at Mt. John were found to be regulated by the interaction between density-dependent mortality and density-independent reproduction. The addition of water and/or fertiliser caused an increase in the reproductive vigour of the plant and a decrease in density while simulated grazing (i.e. mowing) had little effect on the population. A link was found between reproductive vigour and rosette size or age (50% of first year rosettes reproduced while only 11 % of older rosettes did), although the reproductive threshold size (23 mm diameter) appeared to be independent of age. Rosettes grown on soil which had previously supported H pilosella had lower growth and reproductive rates and produced fewer stolons of shorter length. However, there was little support for either the allelopathic or aluminium toxicity hypotheses for these lower growth rates. Spatial population models suggested that in the early stages of colonisation, H pilosella vital rates are such that it has the potential to occupy 100% of available space but as the population matures, vital rates change and it is unable to occupy all available space, probably because of intraspecific competition and a limit on plant size. Spread of patches was predicted to be 0.5 - 0.8 cm/yr by both explicit spatial simulation models and analytical diffusion models. Both spatial and non-spatial models predicted that the most effective agent for biological control would be one which caused an increase in mortality rather than a decrease in fecundity; to reduce a population by more than 50% a control agent would have to either increase mortality by 10 - 15 % or decrease daughter production by 80%.

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Fraser, Elizabeth Anne. "Population Ecology of Thelymitra matthewsii Cheeseman Orchidaceae, in Northern New Zealand". The University of Waikato, 2008. http://hdl.handle.net/10289/2291.

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The terrestrial orchid Thelymitra matthewsii Cheeseman, uncommon in New Zealand, was studied to increase knowledge of the species life cycle, morphology and ecology. Results will enhance future conservation management for the species. New information related to the morphology of T. matthewsii was obtained. The species was found to emerge in one of four discrete life stages of distinctive morphology and height range that remained constant for the season, not developing into a more advanced life stage. The leaf of the three pre adult life stages designated a hook, a spiral, and a non flowering stage, did not inflate at the base, but rose smoothly from the tuber. Apparent morphological differences in the column between descriptions of the Australian taxon and the small New Zealand sample examined suggested further study was needed. Comprehensive monthly monitoring was carried out at five study sites in three locations in the Te Paki area of the Far North, from 2002 to 2004. No patterns emerged in plant life stage succession, flowering, and presence or absence at labels reinforcing the concept that variability was a common component of the population census. Seasonal and partial absence was a major component of the populations. An average of 32.8% of plants, over five study sites, were present throughout three seasons, while 66.9% were recorded as absent (not visible) at monitoring. New plants appearing in 2003 and 2004 showed a high percentage of subsequent absence (mean 85.7%). To determine population stability, recruitment and absence were compared. Plant absence exceeded recruitment by 7% (mean plant absence 30.5%; mean recruitment 23.4%). Plants continued to appear during the monitoring period, and labeled plants increased two-fold over commencement numbers. Adults recorded as 28% of labeled plants over three seasons, were out numbered by pre-flowering stages. Only 5% of population numbers exhibited succession from a smaller to a flowering plant. Life stage modeling indicated a life stage was more likely to be followed by the same stage than an expected successive stage. Thelymitra matthewsii was found to be present in four substrates in the Far North. The survey of vegetation found the indigenous species Kunzea ericoides and the exotic Hakea gibbosa dominant for both height, and cover. Litter and bare ground dominated ground cover. Differences in vegetation and ground cover, of sites supporting T. matthewsii and comparison sites that did not, were minor and suggested that another factor, for example a suitable fungal partner, influenced the species presence or absence. The results of the study indicated the present threat classification of Thelymitra matthewsii is inadequate in the light of the species relatively circumscribed, widely separated habitats, the small number of reproducing individuals and vulnerability to habitat modification.

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Rate, Stephen R., i n/a. "Invertebrate diversity and vegetation heterogeneity : plant-invertebrate relationships in indigenous New Zealand grasslands". University of Otago. Department of Botany, 2005. http://adt.otago.ac.nz./public/adt-NZDU20061025.144447.

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Spatial heterogeneity of the environment, as measured by floral diversity, composition and structure, is known to influence the distribution and diversity of invertebrates. Heterogeneity brought about by anthropogenic disturbance may be a threat to invertebrate diversity. This thesis investigates the impacts of vegetation heterogeneity at a range of scales on the diversity of invertebrate populations in modified high-altitude indigenous grasslands on the Rock and Pillar Range, Central Otago. Invertebrates were sampled in and on the edges of snow tussock fragments to assess whether species richness increased systematically with fragment area. Invertebrate composition was poorly related to fragment area, plant composition and environmental variables. Taxon richness, abundance and/or diversity for three invertebrate groups increased as fragment area decreased, perhaps reflecting an influx of species from the surrounding matrix. For snow tussock leaf invertebrates in autumn, richness and abundance were at least two times lower in tussocks exposed to the wind than those in the centre of fragments, suggesting selection of habitat may be based on microclimatic characteristics. Invertebrates were sampled from the bases of tussocks after they were clipped to simulate three levels of vertebrate grazing. Invertebrate community composition differed between sites and sampling dates but was unaffected by clipping treatment. At the higher altitude site invertebrate abundance was 1.45 times greater and Shannon-Wiener diversity (H�) 1.22 times lower than at the lower altitude site. The latter sampling date had higher abundance (2.12 times) and taxon richness (1.14 times) than the earlier date. Pitfall-trapped invertebrates in cushionfield, herbfield and snow tussock differed in community composition and often by taxon richness, abundance and diversity. Across habitats, plant composition, plant diversity and some environmental variables were correlated with invertebrate variables, but could not be separated from vegetation type. The invertebrates collected in the course of the study are listed. Four Phyla, eight Classes, 24 orders and over 300 taxa were recorded. Almost all taxa are endemic and many have limited distributions and/or are undescribed. A species list is provided with collection altitude, method and habitat type. Invertebrate assemblages from sites differing in altitude, vegetation type and level of habitat modification on the Rock and Pillar Range are compared. Sites differed in species composition and rank orders of abundance and richness. At lower elevations, invertebrate richness was at least 25% less, and standardised trap abundance at least 44% less, than that at the highest elevation. Richness and abundance of exotic invertebrates decreased with increasing altitude. This thesis highlights several points concerning the study of grassland invertebrates and heterogeneity on the Rock and Pillar Range. First, there are differences in invertebrate assemblages at a range of scales. Conserving invertebrate diversity will therefore require altitudinal sequences and different habitat types, including disturbed areas. At high elevations, tussock habitat may be disproportionately important due to its relative rarity. Second, the effects of disturbance on invertebrates were only visible at large spatial scales. Third, there is a paucity of research on New Zealand invertebrates, especially in regard to terrestrial disturbance, which has resulted in a shortfall of biological, distributional, taxonomic and ecological knowledge.

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Ostrow, D. Gigi, i n/a. "Larval dispersal and population genetic structure of brachiopods in the New Zealand fiords". University of Otago. Department of Marine Science, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070308.144342.

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New Zealand�s fourteen deep-water fiords have complex physical and hydrographic features as well as strong environmental gradients, all of which may influence the population structure of organisms that inhabit the fiords. I examined the population structure of the brachiopod Terebratella sanguinea over ecological and evolutionary time scales in relation to physical and hydrographic features of the fiords. To further explore the role of larval dispersal in this system, comparisons between population genetic structure of T. sanguinea and a brachiopod with a contrasting larval dispersal strategy (Liothyrella neozelanica) were made. Aspects of the life history of the articulate brachiopod Terebratella sanguinea were measured. I measured density and size throughout Doubtful Sound and growth at outer (5 km from outer coast) and inner fiord sites (13.5 km from outer coast). Additionally, reproductive periodicity was measured at a single site within Doubtful Sound. Terebratella sanguinea occurred at significantly lower densities and was significantly smaller at the outer fiord site (p < 0.05), however growth rates between an inner and outer fiord site did not differ significantly. Terebratella sanguinea was found to have separate sexes and synchronous maturation of oocytes with spawning occurring in the austral winter. These results indicated that, on an ecological time scale, the environmental gradient of the fiords influences aspects of T. sanguinea population structure. In order to determine the influence of the fiord environment on genetic population structure, patterns among T. sanguinea from across Fiordland were assessed using two genetic markers, and these data were compared to hydrodynamic variables. Ten sites (322 individuals) were included in a preliminary allozyme analysis, and 20 sites (358 individuals) were used for the amplified fragment length polymorphism (AFLP) analysis. Patchy genetic differentiation was revealed with both markers, and a break between Long Sound and the other Fiordland sites was detected with AFLP markers. My results suggest hydrodynamic features of this region may isolate organisms that can disperse only during a planktonic larval phase, however this isolation is visible in genetic patterns only at the most extreme values of the hydrodynamic variables. To better understand how the fiord environment influences population structure of organisms that disperse via planktonic larvae, I compared population genetic structure of two sympatric brachiopod species that differ in planktonic larval duration. Genetic analysis using the AFLP technique revealed population structuring corresponding to the contrasting modes of larval dispersal. AMOVA analysis indicated Liothyrella neozelanica, a brachiopod that broods its larvae, had more limited exchange among sites within a fiord than did T. sanguinea, a brachiopod that does not brood its larvae. In general, the fiord hydrographic conditions may be creating opportunities for local genetic differentiation (for example Long Sound) in organisms capable of longer distance dispersal, but organisms with lower potential for dispersal are more strongly influenced by ontogeny than by hydrography. Understanding the population structure of some of the marine fauna of Fiordland is an important cornerstone for the developing management plan for the area. Conservation of the underwater resources of this World Heritage Area can be successful if the structure of the system and the mechanisms driving this structure are taken into account.

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Rockell, Jennifer, i n/a. "Serum 25-hydroxyvitamin D concentrations and their determinants in the New Zealand population". University of Otago. Department of Nutrition, 2008. http://adt.otago.ac.nz./public/adt-NZDU20080929.142611.

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Adequate vitamin D status plays an important role in bone health and may also protect against Type 1 Diabetes (T1D), multiple sclerosis and certain cancers. Vitamin D is obtained from two sources; diet and through skin synthesis through the action of ultraviolet (UV) light. Dietary intakes of vitamin D are low in New Zealand (NZ) and the majority of our vitamin D comes from UV exposure. The NZ population may be at risk of low vitamin D status because of low dietary intakes, the country�s latitude (35-46 �S), and high proportion of darker skinned Maori and Pacific People. While case reports have described the occurrence of rickets, predominantly in immigrant groups, there are currently no national data on the vitamin D status of the NZ population. Reports of low vitamin D status in countries of similar latitude to NZ justify an examination of New Zealanders� vitamin D status. The best method to assess of vitamin D status is to measure circulating 25-hydroxyvitamin D concentrations. This thesis comprises three main studies. The first two had the following aims: to measure 25-hydroxyvitamin D concentrations and their determinants in a national sample (n=1585) of NZ children aged 5-14 y and to measure serum 25-hydroxyvitamin D concentrations and their determinants in a national sample (n=2948) of New Zealanders aged 15 y and over. The 2002 Children�s Nutrition Survey CNS02 was a year long (December, March-November) cross-sectional survey of a nationally representative sample of NZ school children 5-14 y. Over-sampling of Maori and Pacific children allowed ethnic specific analyses. The 1997 National Nutrition Survey (NNS97) participants were recruited over one year according to an area-based sampling frame with a 3 stage stratified design consisting of primary sampling units, households within each unit, and one randomly selected respondent from each household. Mean (99% CI) serum 25-hydroxyvitamin D concentrations were similar in children and adults (both 50 nmol/L). Among Maori, Pacific and NZEO children respectively, prevalence (%, 99% CI) of serum 25-hydroxyvitamin D deficiency (< 17.5 nmol/L) was 5% (2, 12), 8% (5, 14), and 3% (1,7). Based on a cutoff of < 37.5 nmol/L, prevalence of insufficiency was 41% (29, 53), 59% (42, 75) and 25% (15, 35), respectively. Based on a cutoff of 50 nmol/L, 56% of children were insufficient. Three percent of adult New Zealanders had serum 25-hydroxyvitamin D concentrations indicative of deficiency ([less than or equal to] 17.5 nmol/L); 48% and 84% were insufficient based on cutoffs of [less than or equal to] 50 and [less than or equal to] 80 nmol/L The main determinants of vitamin D status in NZ children were season, ethnicity and sex. After adjustment for other factors and covariates, boys had an adjusted mean (99% CI) 25-hydroxyvitamin D concentration 5 (1, 9) nmol/L higher than girls, Maori children were 7 (2, 11) and Pacific children 15 (11, 20) nmol/L lower than NZ European and Other (NZEO) children. Obese children were 7 (2, 11) nmol/L lower than overweight or �normal� weight. Children�s mean 25-hydroxyvitamin D concentrations (adjusted for other variables) peaked in March (69 nmol/L) and was at its lowest in August (36 nmol/L). In adults, there were effects of a similar magnitude of ethnicity and season on serum 25-hydroxyvitamin D concentrations. Obesity, latitude and age were determinants of vitamin D status in women but not men. Obese (BMI > 30) women had an adjusted mean vitamin concentration 6 (3, 10) nmol/L lower than women with BMI < 25. Women living in the South Island were 6 (3, 9) nmol/L lower than women living in the North Island. Additionally, adjusted mean serum 25-hydroxyvitamin D was 13 (8, 18) higher in women 15 -18 y than women 65 y or older. The third and final study aimed to determine whether the higher rates of vitamin D inadequacy reported in the winter than summer months in NZ also result in higher PTH concentrations, which would provide evidence for functional effect of inadequate vitamin D status. We also aimed to objectively explore the effect of natural skin colour on vitamin D status, given the higher prevalence of vitamin D insufficiency in dark-skinned groups living far from the equator. Skin colour measurements were taken with a hand-held light reflectometer (Datacolor Mercury[TM] 1000 colorimeter, Lawrenceville, NJ). In the 342 residents of Invercargill and Dunedin, mean serum 25-hydroxyvitamin D concentrations were lower in the late summer versus early spring (79 vs 51 nmol/L; P< 0.001). The lower serum 25-hydroxyvitamin D in early spring versus summer was associatedwith a 2 pg/mL (P< 0.001) higher parathyroid hormone (PTH) concentration. Interestingly, no significant effect of natural skin colour, based on light reflectance at the inside of the upper arm, was discovered, though there was a positive effect of tanning, based on light reflectance at the upper forearm, on serum 25-hydroxyvitamin D concentrations. Ethnicity and season are major determinants of serum 25-hydroxyvitamin D in New Zealanders. There is a high prevalence of vitamin D insufficiency in NZ children and adults, which may contribute to increased risk of osteoporosis and other chronic disease. While there is a pressing need for more convincing evidence with regards to the health risks associated with the low vitamin D status in children, evidence from the study of adults, where higher PTH concentrations were found during spring versus summer, suggests that the low 25-hydroxyvitamin D concentrations are having an adverse effect on bone health of adults. The high prevalence of vitamin D insufficiency in New Zealanders, warrants serious consideration of strategies such as fortification, to improve the vitamin D status of the population.

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McKinnon, Jean Fiona, i n/a. "Aspects of the population biology of the southern arrow squid, Nototodarus sloanii, in southern New Zealand". University of Otago. Department of Marine Science, 2007. http://adt.otago.ac.nz./public/adt-NZDU20071204.161531.

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Nototodarus sloanii is an important component of the Southern Ocean fauna, and the basis of a large commercial fishery. Despite this, much is unknown about the biology of this species. This study examines some aspects of the biology of N. sloanii. Stomach contents analysis identified no significant differences in diet between male and female squid. Sixteen putative species, including 12 identifiable teleosts, 2 crustaceans, and 2 cephalopods were identified in the diet of this species. The euphausid, Nyctiphanes australis was the most important prey item, Lanternfish, Lampanyctodes hectoris, and Pearlside, Maurolicus muelleri, were of secondary importance. Squid were aged using counts of statolith micro-increments and back-calculation from the date of capture showed that hatching occurred between August and February, with a peak in the austral winter/spring and another smaller peak in the austral summer. Growth rate for male squid differed depending on whether squid were hatched in the winter/spring or summer. Growth rates were more variable in the winter/spring-hatched individuals, and they attained larger size than summer-hatched squid. This was not the case for female squid. Mean age for immature winter/spring-hatched squid was significantly higher than for summer-hatched squid, although there was no significant difference in mean mantle length or body mass. No significant differences between mean age, mantle length, or body mass for same-gender mature squid, regardless of hatch season, were apparent. However, mature female squid hatched in the winter/spring season were significantly longer (ML) than mature male squid hatched in winter/spring. No squid was found to be older than 211 days. All squid had started to mature by 91-120 days old and all were fully mature at 180 days. Validation experiments run on juvenile squid using calcein markers were inconclusive, however the increments in the statoliths were very similar to those found in other validated species of ommastrephid squid, thus for the purposes of this study they were assumed to be of daily periodicity. Gladius increments identify a gender difference in growth rate, with female squid having a shorter initial slow growth phase than male squid. Gonadosomatic indices (GSIs) were calculated for male and female squid. These were low (7.12%�0.3% for females and 1.9%�0.2% for males) suggesting that these squid are intermittent spawners. This is further supported by a histological examination, which found germinal cells of different stages present in the same gonad. Lack of mature individuals in this study means that these results are suggestive rather than definitive; more examination of the reproductive process of this squid is required. Histological examination was also used to validate the Lipinski maturity scale for use with this species, while some misidentification occurred the scale is useful to place squid into the broad categories of immature, maturing, or mature. New maturity scales were created for N. sloanii utilising these broad categories. Finer-scale identification is not possible using this scale, as maturation appears to be a continuous process. Morphometric measurements were taken from both hard and soft tissues and were analysed using non-metric multidimensional scaling and analysis of similarity. Divisions were only apparent in the hard structure measurements. They did not appear to be age, dietary or reproductive differences.

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Kristensen, Esben Astrup, i n/a. "Population dynamics, spawning and movement of brown trout in Taieri River tributary streams". University of Otago. Department of Zoology, 2007. http://adt.otago.ac.nz./public/adt-NZDU20070314.091924.

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The aim of this study was to investigate population densities and dynamics of brown trout along multiple tributaries of the Taieri River, a large New Zealand river. Relationships between juvenile brown trout population dynamics and food availability, discharge and water temperature were examined in the same lowland stream. Downstream movements of juvenile brown trout were also examined. Trace element analyses of eggs aimed to identify the source of fish spawning in tributary streams. An experimental study of juvenile brown trout collected from downstream and upstream reaches compared patterns of agonistic behaviour amongst trout that were considered to be dominated by either migratory (downstream) or resident (upstream) fish. Longitudinal surveys of juvenile trout abundance were expanded across four additional streams to determine whether there were consistent patterns in population dynamics of brown trout. Large spatial and temporal variation in population dynamics of juvenile brown trout was found in Silverstream with an upstream site having significantly less temporal variation in densities than a downstream site. No effect of food availability on population dynamics was found. Discharge and temperature affected population densities of juvenile brown trout in some years, but could not solely explain the general pattern in spatial variation in population dynamics. Downstream movement was found to be a behavioural strategy used by juvenile brown trout and appeared to contribute to variation in juvenile density. Analysis of trace element signatures in brown trout eggs indicated that upstream spawning migration by anadromous females was restricted by the presence of a steep gorge along the middle reaches of the Taieri River. Patterns of spawning by migratory and resident fish along tributary streams appeared to vary. In Silverstream, spawning by anadromous fish dominated the lower reaches, whereas considerable overlap between anadromous and resident fish was observed in Big Stream. In Cap Burn distinct trace element signatures were observed for redds spawned along upstream and downstream reaches. However, it was not possible to confidently ascribe the source of the redds to main river migrants or Cap Burn resident fish. Behavioural observations of juvenile brown trout collected from upstream (resident) and downstream (migratory) reaches of Silverstream revealed differences in aggression level, with migratory fish being more aggressive. No difference in growth rates was found between fish from the two areas. Furthermore, the social organisation of resident fish was based on the formation of dominance hierarchies, whereas the competitive status of migratory fish was more even. Patterns in spatial and temporal variation in the longitudinal population dynamics and patterns of abundance of juvenile trout were repeated across the five tributaries. Populations in upstream reaches consisted of fish from multiple age classes and exhibited relatively limited variation in densities, whereas juvenile fish dominated populations along downstream reaches and densities varied greatly over an annual cycle. Taken together, these results suggest a general pattern of spatial and temporal variation in the population dynamics of brown trout sub-populations along tributaries of a large New Zealand river. Whilst various environmental factors may contribute to some of the variation, longitudinal separation into resident and migratory populations also appeared to be important. These finding are important for the management of brown trout in both main river channels and tributaries in New Zealand.

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Webber, D'Arcy Nathan. "Demography and Population Projections of the Invasive Tunicate Styela clava in southern New Zealand". Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/4950.

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This thesis is about the demography of the tunicate Styela clava, a species of some notoriety because of its invasiveness and impacts in many parts of the world. Species assemblages have continuously changed throughout evolutionary history, but the rate of today’s anthropogenically facilitated dispersal is unparalleled in history. Non-indigenous species (NIS) are now considered one of the most important risks to native biodiversity. NIS become invasive by becoming both widespread and locally dominant. This requires that a species becomes established, spreads locally, and increases in abundance. In the early stages of invasion, its demography and life history characteristics are of crucial importance. In New Zealand, Styela has established populations in several places, but none of these populations has yet reached the high densities found in other countries. In Lyttelton Port, where this study was located, Styela was first noticed in 2005. It therefore presented an ideal situation to study an invasive species in its early stages of establishment and provided a potentially good model for understanding how invasive species get local traction and spread from initial infestation points. Therefore, I set out to determine demographic features of Styela to understand the numbers game of population dynamics. This study used empirical data on growth rates, size-frequencies through time, and size and age to maturity to test several models, including von Bertalanffy, Logistic dose-response, Ricker and power models of individual growth. The most useful proved to be the von Bertalanffy model. Styela individuals shrink frequently, so average growth rates were often quite low, even though some individuals reached 160 mm or more in total length. Mortality was greatest in summer, presumably after reproduction, and lowest in winter. Fewer than 5% of individuals survived 12 months, and most or all of these died soon afterwards. Populations were, therefore, essentially annual. Recruitment was difficult to determine because of the cryptic nature of small juveniles. However, size-frequency, abundance and mortality data indicated that recruitment most likely occurred in early spring (late-October), and then again in late summer, with growth to maturity (at c. 50 mm total length) within < 5 months. Several manipulative experiments showed that Styela did not readily capitalise on provision of free space but the other non-native ascidian, Ciona intestinalis, rapidly recruited. Transplants of Styela were greatly affected by C. intestinalis, which overgrew them, similar to a localised replacement of Styela by Ciona seen overseas. Lefkovitch modelling was used to test whether Styela had an “Achilles heel” in its life history, whereby managed removal could impact future populations. This showed that under several scenarios intervention would most likely be ineffectual. Overall, this study showed that the original populations in Lyttelton Port are either static or in decline, somewhat contrary to original expectations. Nevertheless, it appears that these small populations may be acting as stepping stones for spread of this species outside of the port.

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Clucas, Rosemary, i n/a. "Kia Whakamaramatia Mahi Titi : predictive measures for understanding harvest impacts on Sooty Shearwaters (Puffinus griseus)". University of Otago. Department of Mathematics & Statistics, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090813.140751.

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The sooty shearwater (also known as the muttonbird, Titi, Puffinus griseus) is a long-lived super-abundant, burrow nesting petrel, harvested by Rakiura Maori from breeding colonies, located in southern New Zealand. The harvest is culturally defining and enormously important for Rakiura Maori. The work in this thesis contributes to the Kia Mau te Titi Mo Ake Tonu Atu Research Project being undertaken by Rakiura Maori and the University of Otago, towards assessing ongoing sustainability of the harvest and future threats. Analyses of eight muttonbirder harvest records spanning, 1938 to 2004, show that harvest rates demonstrate, systematic commonalities in seasonal patterns and broad-scale consistency in trends of chick abundance and quality across harvested islands. If co-ordinated and well replicated, harvest records offer Rakiura Maori a low-cost and effective monitoring tool of sooty shearwater reproductive success and long-term population abundance. Hunt tallies provide additional evidence of a dramatic reduction in sooty shearwater abundance from the late 1980s that was also detected by counts from boats off the western seaboard of the USA. A conservative estimate of overall decline in hunt success across diaries, for the period 1972 to 2004, is 1.89 % (CI₉₅ 1.14 to 2.65) per annum, a total reduction of 39.2%. The harvesting records show a sooty shearwater mortality event occurred just prior to the 1993-breeding season at the same time as a severe negative anomaly in both the Pacific Decadal Oscillation and Southern Oscillation Indices. The hunting diaries show a decoupling of chick size with harvest success in the early 1990s. This resulted from a decline in harvest success and an increase in its variability, while chick size remained correlated with changing chick abundance and maintained its pre-1990 average. Long- lived seabirds maintain high survival by skipping breeding and abandoning breeding attempts when oceanic conditions deteriorate, increasing variability in chick abundance is also evidence of pressure on adult survivorship. The multiple diaries confirm these were major demographic events not confined to a single island. My survival estimates for The Snares and Whenua Hou were very high 0.952 (0.896-0.979) compared to earlier estimates for this species. Transience at the colonies is high due to the presence ofjuvenile and pre-breeding birds. Both naturally high survival and the large number of transient pre-breeders indicate sooty shearwater are more resilient to harvest than earlier survival models suggested. There was no evidence for directional change in sooty shearwater breeding phenology over 49-years of harvest. Climate fluctuation/change is therefore apparently not altering egg-laying. Peak fledging occurred fairly consistently in the 2nd of May (IQR = 2.91 days). Yearly variability in emergence occurs primarily due to provisioning and localized fledging conditions. Larger chick size was strongly correlated with delayed fledging and is consistent with the traditional ecological knowledge of the birders. There was no evidence for chicks becoming smaller or that years with starving chicks were more common, so increasing mismatch of breeding with optimal forage was not indicated. The past proportion of birders over the last 20 years (1985 - 2005) has been ~2% all of Rakiura Maori. Approximately 376 birders participated in the 2006 season with an estimated of overall harvest intensity 19.4% (CI₉₅ = 13.8 - 24.2%) and a total catch of 381,000 (CI₉₅ = 262,257 - 487,186) chicks. This study found evidence that catch rates reduced with increasing birder competition partially mitigating effects on harvest pressure. The combined effects of potential climate change on bird abundance and increased harvester competition suggests that the proportion of Rakiura Maori whom choose to bird is likely to decrease as tallies reduce and cost recovery becomes more difficult. Rakiura Maori have for many years cherished and maintained their islands and implemented protective measures to safeguarded titi breeding habitat. Future harvest management will have additional issues to contend with, but Rakiura Maori are necessarily confronting these issues as the titi culture rests on the maintenance of their taonga. The information presented in this thesis shows that combining science and traditional knowledge is a powerful tool for managing harvest sustainability.

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Becconsall, Karyn, i n/a. "Analysis of radiolucent jaw lesions in a New Zealand population over a twenty-year period". University of Otago. School of Dentistry, 2008. http://adt.otago.ac.nz./public/adt-NZDU20081202.144835.

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The maxilla and mandible may be affected by a wide variety of lesions of developmental, neoplastic or inflammatory origin. These lesions have a vast array of clinical and radiographic presentations from which a dentist forms a clinical provisional diagnosis and treats the lesions accordingly. The aim of this study was to determine the range, demographic and clinical features of all histologically diagnosed radiolucent jaw lesions in a New Zealand population over a twenty-year period. Additionally, the provisional diagnosis was compared to the histopathological diagnosis in an effort to gain an insight into the difficulties practitioners face in clinically diagnosing radiolucent jaw lesions. Material and Methods: From the histopathology diagnostic service at the University of Otago School of Dentistry all specimens with a diagnosis of a radiolucent jaw lesion between 1986 and 2006 were retrieved and classified into six diagnostic categories. For each lesion the age, gender, site, clinical presentation, clinicians provisional diagnosis and the final histological diagnosis was gathered and analysed. Results: During the study period 4983 specimens were identified as radiolucent jaw lesions. The diagnostic category with the largest number of specimens was inflammatory lesions (72.8%), followed by developmental odontogenic cysts (21.8%). Malignant tumours accounted for less than 1% of all specimens. Concordance of provisional and histopathological diagnoses ranged from 81.0% for nasopalatine duct cyst to 0% for the majority of intra-osseous malignant tumours. Conclusions: The range and demographic features of radiolucent jaw lesions in this study are comparable to that of other populations with a European majority. No radiolucent jaw lesion can be reliably accurately diagnosed from clinical presentation and radiographic appearance alone.

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12

Miller, Laura Jean. "Population mixing and the geographical epidemiology of childhood leukaemia and type 1 diabetes in New Zealand". Thesis, University of Canterbury. Geography, 2008. http://hdl.handle.net/10092/1530.

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Over the past twenty years the incidence of both childhood acute lymphoblastic leukaemia (ALL) and type 1 diabetes have risen in many developed countries, including New Zealand. Although the explanations for this increase and the precise aetiology of both diseases remain unclear, environmental factors are thought to be important. One factor receiving increasing attention is the role of infections introduced through population mixing. However, previous studies on this topic show mixed results and population mixing itself tends to be under-theorised. Furthermore, this issue has not been adequately assessed in New Zealand, a country characterised by high levels of population mobility. In this research, a variety of population mixing measures for small areas in New Zealand were developed. National data on ALL registrations were obtained from the New Zealand Cancer Registry, and regional type 1 diabetes data were obtained from the Canterbury Diabetes Register for the Canterbury Region of the South Island. The analyses were undertaken in three stages. First, standardised incidence ratios of each disease were examined at different geographical and temporal scales, between areas of differing socioeconomic status, and in urban and rural New Zealand. Second, cluster analysis was employed to test for spatial-temporal clustering of the two diseases. Finally, multivariate regression analyses were utilised to investigate the association between each disease and the various measures of population mixing at the area-level. The results reveal similarities in the geographical epidemiology of childhood ALL and type 1 diabetes in New Zealand. The majority of the findings were suggestive of an infectious aetiology for both diseases. In addition, higher incidence of both diseases was observed in areas which increased the most in population mixing over short time periods (6/7 years). Furthermore, raised type 1 diabetes incidence was also associated with high population mixing in early life.

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Dillingham, Peter W., i n/a. "Population modelling of albatrosses and petrels with minimal demographic information". University of Otago. Department of Mathematics & Statistics, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090813.152547.

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There are hundreds of thousands of fisheries-related mortalities of seabirds each year. Population trends for these species are highly influenced by changes in adult survival, their maximum growth rates are low, and little additional mortality can have a large impact on the population. As a result, many albatrosses and petrels are at risk of extinction, but limited demographic data makes it difficult to quantify the risk for many species. The goal of this research is to use population modelling tools to assess potential impacts with minimal data. In particular, the question of how much additional mortality a population can sustain is addressed when there is only knowledge of the adult survival rate, age at first breeding, and the number of breeding pairs. In this thesis, a simple decision rule designed for marine mammals is applied to albatrosses and petrels. In order to use this rule, adult survival, age at first breeding, a minimum estimate of the population size, and the maximum growth rate of the population are needed. While estimation of adult survival is well developed, work was required to calculate the other values from available data. A simple population model was developed to extrapolate from the number of breeding pairs to the total population size (given survival and age at first breeding); the effect of variable fecundity rates on the calculation of generation time and the maximum growth rate of a population was examined, relative to an estimate that only requires survival and age at first breeding; and a method for estimating the age at first breeding using capture-recapture data was suggested that accounts for study duration and emigration, in addition to capture probability. This work can help managers make better informed decisions when little is known about a population. For example, around 5,800 pairs of Gibson's albatrosses (Diomedea gibsoni) breed each year. Based on the work presented in this thesis, they may be able to sustain 1,000 - 1,200 additional mortalities per year. However, given concern about their conservation status, a mortality level below 100 - 120 is desired, and any mortality beyond that level suggests a need for more intensive management.

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Debruyne, Christine Anne. "Fluctuating asymmetry and body morphology in relation to population bottlenecks of introduced birds in New Zealand". Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/3326.

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The introduction of exotic bird species to New Zealand (NZ) from the United Kingdom (UK) over 100 years ago unintentionally created an ideal study system to examine potential changes in developmental stability due to bottleneck effects. In this study I measured fluctuating asymmetry (FA; random deviations from symmetry between bilaterally symmetrical traits) in 13 species of introduced birds in NZ. FA has been used for conservation purposes as an early warning system of increased developmental instability (DI; the inability to cope with random genetic or environmental perturbations during development). I evaluated DI using FA in several anatomical external and internal morphological traits, and compared differences in body morphology between introduced and source populations in relation to the bottleneck size. I also examined FA in nestlings in two closely related introduced species that passed through two different-sized population bottlenecks. Differences in FA in relation to bottleneck severity were only observed in external traits. FA in external traits in some NZ populations differed from their UK counterparts, but it was in the opposite direction than predicted. FA in external traits varied significantly across NZ populations of introduced species - the most severe bottlenecks species exhibited higher levels of FA than species that passed through larger bottlenecks. There were no patterns in FA and bottleneck size for skeletal traits, most likely due to differences in environmental and genetic stressors resulting in species- and characterspecific FA relationships. Nestling FA was the same for both species, despite the large difference in bottleneck size. FA did decrease over the nestling period, although not at the same rate for each trait, most likely due to the differing costs of development, functional importance, and other environmental stressors that might influence FA in each trait differently. Overall changes in body morphology occurred in four species introduced to NZ, and all species exhibited some changes in trait morphology but were not related to bottleneck size. Finally, the proportion of deformities (deviations from normal phenotype) was higher in NZ than in UK suggesting passing through a bottleneck increased the probability of abnormalities. Although the associations between FA, body morphology and bottleneck severity are complex, my results confirm that measures of morphology have the potential of being useful indicators of DI in the management of endangered species.

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15

Kinnison, M. T. "Life history divergence and population structure of New Zealand chinook salmon : a study of contemporary microevolution /". Thesis, Connect to this title online; UW restricted, 1999. http://hdl.handle.net/1773/5316.

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16

Allen, Sophy Elizabeth. "The effect of population bottleneck size on parasitic load and immunocompetence of introduced birds in New Zealand". Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/1951.

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I investigated parasitic infection and immunocompetence in populations of introduced bird species in New Zealand (NZ) that had experienced a range of population bottlenecks (11-808 individuals), and compared these parameters to non-bottlenecked conspecifics in the United Kingdom (UK). My aims were two-fold; firstly to assess if population bottlenecks are linked to increased parasite loads and/or decreased immunocompetence, and secondly, to assess at what severity of bottleneck these effects become evident. I found that ectoparasite load (chewing lice, Order: Phthiraptera, Sub-Orders: Amblycera & Ischnocera) was significantly higher in the more severely bottlenecked species in NZ than in the UK, whilst this difference became non-significant at more moderate bottlenecks. The difference was mainly driven by the Sub-Order Amblycera. The prevalence of avian malaria (Plasmodium spp.) was significantly negatively correlated to bottleneck size within NZ, after controlling for body mass. Total leucocyte and differential lymphocyte counts were elevated in the less bottlenecked species that were infected with malaria, whilst the populations at the more severe end of the bottleneck spectrum did not exhibit such a response. Furthermore, heterophil/lymphocyte (HL) ratio (a parameter used as an indicator of environmental and/or immunological stress), was significantly raised in the more bottlenecked species when compared to their UK counterparts, and this difference was correlated with the size of the bottleneck. Immunocompetence was further assessed by the experimental challenge of six introduced birds species in NZ with the mitogen phytohaemagglutinin (PHA). Immune response to PHA was significantly correlated to bottleneck size, but in the opposite direction to that predicted; immune response was greater in the more bottlenecked species. However, this may be an indication of increased investment in immunity, due to increased parasite and pathogen pressure or differential investment in varying components of the immune system. Finally, the immune response to PHA was compared in nestlings of two species that had experienced very different bottlenecks (70 vs. 653). After controlling for ectoparasitic infestation, I found no difference between the two species; however, this finding may be confounded by interspecific competition. Overall, my findings suggest that more severe population bottlenecks may result in increased susceptibility to pathogens, and impact on the immune system. This has a number of implications for the development of conservation protocols, and future avenues of research are suggested.

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17

Smith, Derek, i n/a. "Movements, population dynamics and predatory behaviour of stoats inhabiting alpine grasslands in Fiordland". University of Otago. Department of Zoology, 2006. http://adt.otago.ac.nz./public/adt-NZDU20070330.160940.

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Stoats are introduced mammalian carnivores implicated in the decline of several of New Zealand�s endemic species. Most research into stoats in New Zealand has focused on beech forest habitat, especially in years of peak stoat abundance following heavy beech seedfall and peak cohorts of mice. In New Zealand, alpine grasslands occur above the altitudinal limit of beech forest (900-1000 m a.s.l.). Although previous research has shown stoats to be present there, little is known about the ecology of stoats in alpine grasslands. This research aimed to test whether alpine grasslands were a marginal habitat occupied by surplus stoats that had spilled over from beech forest populations, i.e. a sink habitat. The alternative is that alpine grasslands are a desirable habitat deliberately exploited by stoats. This question was answered using mark-recapture, radio-tracking, diet analysis and a food addition experiment. Another objective was to determine whether nest survival is higher in alpine grassland compared to beech forest and whether stoats are likely to be a frequent predator of ground nests in alpine grasslands relative to other introduced mammals that inhabit them. If nest survival is higher in alpine grassland then alpine grasslands may be a refuge from predation. However, if it is not then it is important for management to know the relative risk posed by stoats compared with other predators. An artificial nest experiment was used to answer these questions. This research was undertaken during two years of low to intermediate beech seedfall and therefore provided an opportunity to look at the ecology of stoats in a New Zealand National Park outside years of peak abundance. The principal study site for this research was the Borland Valley, Fiordland National Park. Compositional analysis showed that stoats in alpine grassland selected for it over adjacent beech forest. The range cores of these stoats were high up in alpine grassland away from the ecotone with beech forest. Stoats occurred at similar densities in alpine grasslands as they did in beech forest and observed survival was similar between the two habitats (with the exception of 2004 when it may have been higher in alpine grassland). The most frequent prey of stoats inhabiting beech forest were birds and mice. Although stoats in alpine grasslands also ate birds and mice their most frequent prey were ground weta and hare. Food addition appeared to cause diet switching but did not reduce the distances moved by stoats, suggesting that other factors may be more important in regulating their summer home range size in alpine grasslands. All of these factors lead to the conclusion that alpine grasslands in the Borland are not a marginal habitat for stoats, but may instead be a desirable one. Artificial nests had a higher probability of survival in alpine grassland compared to adjacent beech forest, but survival was too low to support the idea that alpine grasslands are a refuge. Stoats were the most frequent predator of artificial nests in both habitats, but 95 % confidence intervals overlapped the predation rate by possums, which was also high. These findings illustrate the need for a comprehensive landscape approach to stoat control in montane National Parks, for two reasons: 1) endemic biodiversity in alpine grasslands may be under threat from stoat predation, 2) alpine grasslands may act as a source for dispersing stoats that reinvade lowland stoat control areas. In the absence of heavy beech seedfall and peak mouse abundance, stoats occurred at densities of around 1 km⁻� in both habitats and there was recruitment into these populations. This raises the important question: What regulates the distribution and abundance of stoats in years of low beech seedfall and low mouse abundance? In these years birds, ground weta and hares may be as important as mice are in years of peak abundance following heavy beech seedfall.

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West, David William. "Responses of wild freshwater fish to anthropogenic stressors in the Waikato River of New Zealand". The University of Waikato, 2007. http://hdl.handle.net/10289/2601.

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To assess anthropogenic impacts of point-source and diffuse discharges on fish populations of the Waikato River, compare responses to different discharges and identify potential sentinel fish species, we sampled wild populations of brown bullhead catfish (Ameiurus nebulosus, (LeSueur, 1819)), shortfin eel (Anguilla australis Richardson, 1848), and common bully (Gobiomorphus cotidianus McDowall, 1975) in the Waikato River. Sites upstream and downstream of: geothermal; bleached kraft mill effluent (BKME); sewage and thermal point-source discharges were sampled. At each site, the population parameters, relative abundance, age structure and individual indices such as: condition factor; and organ (gonad, liver, and spleen) somatic weight ratios; and number and size of follicles per female were assessed. Indicators of fish residence and in some cases exposure to contaminants in discharges were analyzed. Bile chemistry of brown bullhead and shortfin eel was assayed, liver and muscle metal levels were analyzed for brown bullhead and shortfin eel respectively, and stable isotopes of C and N in common bully were measured. Bile, metal and isotopic signatures gave strong evidence that fish had been resident at sites for some time before sampling. Signatures of bile and metal contaminants showed contamination was localised to discharge areas. Gradients in stable isotopes in common bully showed evidence of changes in water sources and anthropogenic effects along the river. Biochemical variables, hepatic ethoxyresorufin-O-deethylase (EROD) and plasma steroids indicated exposure and response of brown bullhead and shortfin eel to pulp and paper contaminants at the BKME site. Physiological (blood) variables showed fish largely responded in a predictable way to elevated water temperatures at discharge sites at time of sampling, however total haemoglobin of brown bullhead and common bully blood failed to increase at the BKME site despite elevated temperatures and low dissolved oxygen. Growth rates, condition factor, age structure, and gonadosomatic index (GSI) suggest that discharges with significant heat or nutrients benefit brown bullhead despite physiological impairment at the BKME site. Shortfin eel individuals also benefited from heated water discharges. No consistent impacts on common bully health were obvious at individual discharge sites, or cumulatively along the river due to the gradual deterioration in water quality downstream. Common bully individuals also benefited from heat in discharges but lack of juveniles at sites where numerous juvenile brown bullhead were found, suggest that unlike brown bullhead populations, common bully populations were not responding with significant recruitment. Although I found little evidence of toxic effects of discharges on shortfin eel, caution is required in assessing the potential of contaminants to impact eel populations due to the life history of shortfin eel, and exploited nature of populations. For example, reproductive damage suffered by adult eels may not immediately manifest itself in the effected population due to temporal delays in gonadal maturation, and recruitment, and single panmictic populations supplementing recruitment of impacted populations. Distinct changes in population parameters at each of the paired sites and changes in individual variables showed that fish responded to discharges. The range of responses in species suggests different sensitivity to contaminants and amount of benefit which each species receives from heat in discharges. In these terms shortfin eel would be the most resistant, then brown bullhead and lastly common bully. Interpretation of population-level impacts at the geothermal and BKME discharge sites is made difficult due to benefits of additional heat. There is also the possibility that detection of sub-lethal or chronic effects on sensitive juvenile life-stages may be being hidden by compensatory density population responses. Responses and life history of common bully made them the preferred indicator species of the three species sampled, and supported overseas examples using small-bodied fish species as sentinels.

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Idle, Julian Clifford. "The preparedness and response of the population of Lyttelton, New Zealand, and surrounding areas, for and to hazards". Thesis, University of Canterbury. Department of Geological Sciences, 2012. http://hdl.handle.net/10092/7245.

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Small, tight-knit communities, are complex to manage from outside during a disaster. The township of Lyttelton, New Zealand, and the communities of Corsair Bay, Cass Bay, and Rapaki to the east, are especially more so difficult due to the terrain that encloses them, which caused them to be cut-off from Christchurch, the largest city in the South Island, barely 10 km away, after the Mw 7.1 Darfield Earthquake and subsequent Canterbury Earthquake Sequence. Lyttelton has a very strong and deep-rooted community spirit that draws people to want to be a part of Lyttelton life. It is predominantly residential on the slopes, with retail space, service and light industry nestled near the harbour. It has heritage buildings stretching back to the very foundation of Canterbury yet hosts the largest, modern deep-water port for the region. This study contains two surveys: one circulated shortly before the Darfield Earthquake and one circulated in July 2011, after the Christchurch and Sumner Earthquakes. An analytical comparison of the participants’ household preparedness for disaster before the Darfield Earthquake and after the Christchurch and Sumner Earthquakes was performed. A population spatiotemporal distribution map was produced that shows the population in three-hourly increments over a week to inform exposure to vulnerability to natural hazards. The study went on to analyse the responses of the participants in the immediate period following the Chrsitchurch and Sumner Earthquakes, including their homeward and subsequent journeys, and the decision to evacuate or stay in their homes. Possible predictors to a decision to evacuate some or all members of the household were tested. The study also asked participants’ views on the events since September 2010 for analysis.

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20

Laws, Rebecca, i n/a. "The causes of nest failure and effects of inbreeding depression in a historically small population of New Zealand Stewart Island robins". University of Otago. Department of Zoology, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090813.114240.

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Inbreeding depression is one of the factors that can increase the risk of extinction of small populations, and therefore understanding its effects is currently an important issue in conservation biology. Until recently, few studies on inbreeding depression were carried out in wild populations. These recent studies have highlighted the variability in detecting inbreeding depression among natural populations and the multitude of factors that can influence its expression. Many of the factors affecting inbreeding depression in wild populations remain largely unexplored and most of the recent studies in this area have tended to focus on incidents of inbreeding in populations with a history of large population size. The aim of this study is to investigate the relative importance inbreeding depression has had on individual fitness parameters in a population of New Zealand's Stewart Island robins Petroica australis rakiura introduced to Ulva Island. This island population has historically gone through several population bottlenecks. Four main factors that potentially influence the rate of inbreeding and the extent of inbreeding depression, were investigated: environmental variability, life history stage, genetic load and dispersal. Generalized Linear Mixed Modelling was first used to determine how weather affected nest survival. Weather effects were then incorporated into models containing demographic factors to control for environmental variability, and finally parental, maternal and paternal inbreeding co-efficients (=f) were added to models to determine the relative importance of inbreeding depression. Interactions between inbreeding depression and environmental factors were explored. Three different life history stages were compared to determine the differences in inbreeding depression at each stage as well as cumulative effects over time. The genetic load of the population was estimated using lethal equivalents allowing for standardised comparison of inbreeding depression with other species. The likelihood of inbreeding in the population was also explored by investigating the factors affecting dispersal patterns and evaluating evidence for inbreeding avoidance. Inbreeding depression was found to be mild in the robin population. Weather did not have strong effects on nest survival or interactions with inbreeding. Female age was the only factor interacting with inbreeding, with younger inbred females experiencing significantly reduced offspring juvenile survival. Parental and paternal f did not significantly affect brood survival at any life history stage, however, maternal f showed significant effects on nest juvenile survival with the strongest effect occurring when survival was examined cumulatively over all life history stages. The Stewart Island robin had a relatively low lethal equivalent value compared to the closely related North Island robin and other avian species. This difference was associated with the Stewart Island robin having a low genetic load, most likely due to historical genetic purging during periods of population bottleneck. The Ulva Island robin population did not appear to be avoiding inbreeding through dispersal. Dispersal distance was most strongly influenced by the location of the natal nest of the dispersing offspring. In conclusion, the genetic history of the population was likely to have had the strongest impact on the severity of inbreeding depression in the Ulva Island robin population. The results of the thesis highlight the need to examine a number of factors to be able to explain variability in inbreeding depression among populations.

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Ramrakha, Sandhya, i n/a. "The link between mental health problems and sexual risk taking in a general population sample". University of Otago. Dunedin School of Medicine, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090527.155127.

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This thesis examined whether mental health problems and sexual risk taking were associated in a general population sample and if so, the extent and direction of this association. The thesis begins with a review of theories of risk taking; sexual risk and mental health correlates; and the existing studies linking mental health and sexual risk taking. Three empirical studies were conducted. Study One produced new evidence that a range of psychiatric disorders were linked to early sex (<16 years), risky sex (multiple partners and inconsistent condom use in the past year at age 21) and sexually transmitted infections (STIs) by the age of 21 years. Young people who present with schizophrenia spectrum disorder were also prone to early and risky sex and STIs. Second, depression, the single most common psychiatric problem in the population, was also associated with risky sex and STIs. The risk increased with comorbid psychiatric conditions. Study Two addressed the issue of directionality, specifically examining if childhood behavioural and emotional problems and early adolescent psychiatric disorder predicted later sexual risk taking and STIs. Main findings showed that childhood antisocial behaviour increased the likelihood of risky and early sex, and that low levels of childhood anxiety increased the likelihood of later risky sex and having STIs. Involvement with delinquent peers mediated the association between childhood antisocial behaviour and risky and early sex. To a lesser degree, attachment to parents mediated the association between antisocial behaviour and early sex. These factors did not mediate the association between low levels of childhood anxiety and later sexual outcomes. No associations were found between adolescent psychiatric disorder and later sexual risk taking, with the exception of conduct disorder. However, it is important to note that by excluding the group who had early sex in order to establish temporality, other behaviours of interest exhibited by this group were also excluded. The third study examined whether sexual risk taking was associated with an increased risk of subsequent mental health problems, addressing the issue of directionality in the other direction. Main findings showed that reports of early sex, multiple sex partners and STIs elevated the risk of later substance dependence disorders. Importantly, this association persisted after controlling for �baseline� levels of psychiatric disorder. Early sex also predicted later conduct disorder, even after controlling for prior conduct disorder. In contrast, early sex, multiple sex partners and acquisition of STIs were unrelated to later diagnoses of anxiety or depression. The significant associations with multiple sex partners and STIs were also shown for incident cases of substance dependence. Moderation analyses revealed no differences between the sexes in any of the studies except in Study Three. Specifically, the association between multiple sex partners and substance dependence appeared to be stronger for males than females for up to 10 sex partners and substantially stronger for females than for males beyond ten sex partners. The final chapter in this thesis reviews the strengths and weaknesses of the studies in this thesis before considering the implications of the results for theory, research and practice.

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22

Fowler, Anthony, i Gretel Boswijk. "Chronology Stripping as a Tool for Enhancing the Statistical Quality of Tree-Ring Chronologies". Tree-Ring Society, 2003. http://hdl.handle.net/10150/262571.

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Replication is a key principle in tree-ring research. Dendrochronologists strive to maximise sample size to enhance the "signal" in tree-ring chronologies, often relying on crossdating to provide an effective quality control filter. However, is crossdating alone a sufficient quality test for incorporating a series into a site chronology? We address this question using an objective and automated "chronology stripping" method designed to maximise the chronology's "Expressed Population Signal" (EPS), by iteratively removing series which lower chronology EPS. A 15-site data set of Agathis australis (D. Don) Lindley is used to demonstrate the method. Results suggest that modest benefits may be gained by chronology stripping, but the quality control implicit in crossdating is indeed effective, at least for Agathis australis.

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23

Tezanos, Pinto Gabriela. "Population structure, abundance and reproductive parameters of bottlenose dolphins (Tursiops truncatus) in the Bay of Islands (Northland, New Zealand)". Thesis, University of Auckland, 2009. http://hdl.handle.net/2292/5799.

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Bottlenose dolphins (Tursiops truncatus) occupy a wide range of coastal and pelagic habitats throughout tropical and temperate waters worldwide. Around New Zealand, bottlenose dolphins inhabit three discontinuous regions in the north-eastern coast of the North Island, Marlborough Sound and Fiordland in the South Island. All these populations are subject to anthropogenic activities including dolphin-based tourism industry. Along the north-eastern coast of the North Island, the Bay of Islands presents a unique opportunity to study this population because of regular occurrence year-round and a history of long-term studies conducted in the region. This study examines the population structure and genetic diversity of the three New Zealand bottlenose dolphin populations to define their boundaries. Second, it focuses on the Bay of Islands subpopulation to investigate the dynamics of dolphin groups, pattern of habitat use, abundance and trends over time. Finally, it estimates reproductive parameters of female bottlenose dolphins to predict the long-term viability of the Bay of Islands subpopulation.

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Carroll, Emma Louise. "Return of the right whale: assessment of abundance, population structure and geneflow in the New Zealand southern right whale". Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/11541.

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Southern right whales were hunted to near extinction, with an estimated 150,000 killed by intensive 19th century and illegal 20th century whaling. This thesis focuses on the coastal calving grounds of New Zealand (NZ) and Australia, where previous genetic work and survey work suggests 2 genetically distinct stocks are recovering ... Overall, the picture is encouraging for the recovering NZ southern right whale, suggesting the population is increasing at a rate comparable with conspecific stocks. The status of the NZ southern right whale as a distinct stock based on differentiation of mtDNA haplotypes is supported by the demographic closure inferred from paternity analyses. However, the stock continues to winter almost exclusively in the Auckland Islands and remains at <10% of its prewhaling abundance. The restricted range and demographic closure means it is vulnerable to local catastrophe and should continue to be monitored.

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25

Hutton, Nicole Suzanne. "Population Dynamics and Vulnerability Reduction: The Role of Non-Profit Organizations Following the 2011 Earthquake in Christchurch, New Zealand". Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/5964.

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With the adoption of neo-liberal policies and the decline in social welfare, non-profit organizations have been increasingly integrated into public service provision. Such changes raise questions regarding formal policies and access for marginalized populations, no more so than in disaster settings as formal disaster management of sexual health services are still vague. This study identifies the role of non-profit organizations in providing public health and social services through the lens of sexual health commitments following the September 2010 Darfield Earthquake and subsequent major aftershock during February 2011 in Christchurch, New Zealand. The primary goals of this study were three fold, to delineate i) aspects of non-profit organizational culture and agency connections that contributed to the resilience of non-profit organizations by maintaining and adapting access to sexual health and associated wellbeing services over the transition from response to recovery ii) integration pathways of non-profit organizations into disaster risk reduction and iii) appropriate geographic representations of temporal vulnerability change impacting the commitments of non-profit organizations. Mixed methods were used for this study. Data were collected over a two-year period between 2013 and 2015. Data collection techniques included: i) archival research ii) surveys iii) focus groups and iv) semi-structured interviews. Quantitative data were derived from census records and qualitative data from surveys, focus groups, and interviews with non-profit and civil society practitioners. A total of thirty-six non-profit organizations, civil society partners, and agency connections participated. Results show that sexual health needs of youth, families, and migrants arriving for the rebuild, fluctuated following the earthquakes. Sexual health non-profits absorbed the shifting demands for services and supplies by leveraging government partnerships and non-profit agency connections to account for fluctuations in presenting populations, adjust service delivery methods and continue advocacy campaigns. Also, as a result of functional redundancy amongst migrant support groups and their respective agency connections, strategies of long-term advocacy commitment, co-location, and relationship building with diverse ethnic groups benefitted migrants and refugees in maintaining or accessing adequate health and wellbeing support into the recovery phase. By developing programs to increase public awareness of resources, creating engagement opportunities in vacant spaces, and bringing a united voice to authorities, non-profits captured increased social cohesion to address emergent and compounded vulnerabilities of marginalized populations. However, as the recovery progressed, some collective energy was lost. Findings indicate that non-profits operating in Christchurch prior to the earthquakes with flexible organizational structures and those that emerged after were most successful in the emergency response and early recovery. The ability to capture social cohesion resulting from the shared experience of the earthquakes and build bridges with non-profit connections or incorporate emergent populations into service delivery facilitated successful operations into recovery. Non-profits that partnered with the government were better suited for long-term recovery, when interagency collaboration returned to a more competitive state and reliance on co-production of services was reestablished as the preferred method of service delivery, based on their capacity to maintain and build linkages with civil society partners. This research adds to disaster literature and the understanding of organizational behaviors by suggesting appropriate means to assess the potential resilience of non-profit organizations post-disaster. Further, pathways of integration with disaster management are identified for various types of non-profits that contribute to sexual health and related community support services. Methods used to identify vulnerabilities of wellbeing focused non-profit organizations and model integration of culturally appropriate service delivery options into recovery planning and disaster mitigation can be applied to other high-income nations with burgeoning non-profit sectors that experience variety of hazards, in particular on the United States’ West Coast as the health care debate in the United States continues.

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Wallace, Matthew Fitzgerald. "Using population genetics to assess the dispersal patterns of the New Zealand mayfly Coloburiscus humeralis in a landscape context". Thesis, University of Canterbury. Biological Sciences, 2013. http://hdl.handle.net/10092/9690.

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Mayfly species, such as Coloburiscus humeralis, are an important organism in freshwater ecosystems. As well as often being crucial intermediary links in food webs, mayfly nymphs provide a number of vital in stream functions that contribute to ecosystem health. The threat to stream invertebrate populations from habitat destruction as well as chemical and nutrient additions from agricultural land use has had considerable attention in New Zealand. However, less has been done on the potential barriers to dispersal that may negatively affect the health of stream insect populations. The goal of this study was to use AFLP techniques to measure the genetic structure of populations between streams and across catchments, and thereby to better understand the dispersal of this species across the landscape. I sampled populations in 10 forested streams, ranging from populations separated by <2km to 780 km. I found that in the Arthur’s Pass study area, populations of C. humeralis had high levels of genetic divergence even between the closest streams in the study (ΦPT = 0.065, p = 0.011). In order to identify the landscape features that either constrain or assist mayfly dispersal, I employed a resistance modelling technique based on electrical circuit theory to simulate how particular landscape factors contribute to the observed genetic structure. My resistance modelling results suggest that open areas provide barriers to dispersal while gene-flow was more likely to occur when streams are separated by connected native forest.

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Allentoft, Morten Erik. "An Ancient DNA Study of Four Sympatric Species of Moa (Aves: Dinornithiformes) from Holocene Deposits in North Canterbury, South Island, New Zealand". Thesis, University of Canterbury. Biological Sciences, 2010. http://hdl.handle.net/10092/5264.

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Ancient DNA (aDNA) was isolated from the bones of 290 individuals and four species of extinct New Zealand moa. All sampled bones had been recovered from a small geographic area (~10 km radius) near Waikari in North Canterbury. A total of 217 specimens were 14C-AMS dated, providing a temporal framework for the genetic analyses and an unprecedented opportunity to study extinct megafauna at the population level. Taxon and sex were determined for each individual, using aDNA technology. This revealed a large excess of females (overall ♂:♀ = 1:5.1), and significant compositional differences for the moa assemblages between fossil sites. Balanced sex ratios were observed among juvenile moa, suggesting that a gender-bias developed as the birds matured, probably as a result of higher male mortality. Female territoriality and ecological niche-separation are discussed in this context. Mitochondrial DNA (mtDNA), amplified using a quantitative PCR procedure, provided a measure of DNA preservation in each radiocarbon-dated fossil. This assessment showed that DNA degrades over thousands of years according to an exponential decay model, and the average molecular half-life for the here targeted DNA fragment was estimated to be 521 years. By using high-throughput sequencing, six polymorphic moa microsatellite markers were identified and characterised. These are the first microsatellite primers developed exclusively for extinct taxa. A high-resolution genetic study of the four sympatric moa populations was carried out, combining information from mtDNA, microsatellites, sex-identification, and radiocarbon age. Genetic diversity, past demography, kinship, and other aspects of moa biology were analysed. The populations showed a remarkable extent of genetic stability throughout the 3000-4000 years preceding their extinction, suggesting that they were large and viable before suddenly disappearing. The results represent significant advances in aDNA research and thanks to the high resolution in microsatellite markers, moa have here been studied, almost as if they were still alive.

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Pontin, David R. "Factors influencing the occurrence of stinging jellyfish (Physalia spp.) at New Zealand beaches". Lincoln University, 2009. http://hdl.handle.net/10182/1580.

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Individuals of the cnidarian genus Physalia are a common sight at New Zealand beaches and are the primary cause of jellyfish stings to beachgoers each year. The identity of the species and the environmental factors that determine its presence are unknown. Lack of knowledge of many marine species is not unusual, as pelagic invertebrates often lack detailed taxonomic descriptions as well as information about their dispersal mechanisms such that meaningful patterns of distribution and dispersal are almost impossible to determine. Molecular systematics has proven to be a powerful tool for species identification and for determining geographical distributions. However, other techniques are needed to indicate the causal mechanisms that may result in a particular species distribution. The aim of this study was to apply molecular techniques to the cnidarian genus Physalia to establish which species occur in coastal New Zealand, and to apply models to attempt to forecast its occurrence and infer some mechanisms of dispersal. Physalia specimens were collected from New Zealand, Australia and Hawaii and sequenced for Cytochrome c oxidase I (COI) and the Internal transcribed spacer 1 (ITS1). Three clans were found: a Pacific-wide clan, an Australasian clan and New Zealand endemic clan with a distribution confined to the Bay of Plenty and the East Coast of the North Island. Forecasting Physalia occurrence directly from presence data using artificial neural networks (ANN) proved unsuccessful and it was necessary to pre-process the presence data using a variable sliding window to reduce noise and improve accuracy. This modelling approach outperformed the time lagged based networks giving improved forecasts in both regions that were assessed. The ANN models were able to indicated significant trends in the data but would require more data at higher resolution to give more accurate forecasts of Physalia occurrence suitable for decision making on New Zealand beaches. To determine possible causal mechanisms of recorded occurrences and to identify possible origins of Physalia the presence and absence of Physalia on swimming beaches throughout the summer season was modelled using ANN and Naϊve Bayesian Classifier (NBC). Both models were trained on the same data consisting of oceanographic variables. The modelling carried out in this study detected two dynamic systems, which matched the distribution of the molecular clans. One system was centralised in the Bay of Plenty matching the New Zealand endemic clan. The other involved a dynamic system that encompassed four other regions on both coasts of the country that matched the distribution of the other clans. By combining the results it was possible to propose a framework for Physalia distribution including a mechanism that has driven clan divergence. Moreover, potential blooming areas that are notoriously hard to establish for jellyfish were hypothesised for further study and/or validation.

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Kardos, Julian, i n/a. "Visualising attribute and spatial uncertainty in choropleth maps using hierachical spatial data models". University of Otago. Department of Information Science, 2006. http://adt.otago.ac.nz./public/adt-NZDU20060908.151014.

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This thesis defines a novel and intuitive method to visually represent attribute uncertainty, and spatial boundary uncertainty generated from choropleth maps. Like all data, it is not possible to know exactly how far from the truth spatial data used for choropleth mapping is. When spatial data is used in a decision-making context a visual representation of data correctness may become a valuable addition. As an example, the visualisation of uncertainty is illustrated using choropleth mapping techniques superimposed on New Zealand 2001 census data, but other spatial datasets could have been employed. Both attribute and spatial uncertainty are considered, with Monte Carlo statistical simulations being used to model attribute uncertainty. A visualisation technique to manage certain choropleth spatial boundary issues (i.e. the modifiable areal unit problem - MAUP) and uncertainty in attribute data is introduced, especially catering for attribute and choropleth spatial boundary uncertainty simultaneously. The new uncertainty visualisation method uses the quadtree spatial data model (SDM) in a novel manner. It is shown that by adapting the quadtree SDM to divide according to uncertainty levels possessed by attributes (associated with areal units), rather than divide on the basis of homogeneous regions (as the original quadtree design was intended), a measure of attribute and choropleth spatial boundary uncertainty can be exhibited. The variable cell size of the structure expresses uncertainty, with larger cell size indicating large uncertainty, and vice versa. The new quadtree SDM was termed the trustree. A software suite called TRUST v1.0 (The Representation of Uncertainty using Scale-unspecific Tessellations) was developed to create square trustree visualisations. The visual appeal and representational accuracy of the trustree was investigated. Representative accuracy and visual appeal increased when using hexagonal tessellations instead of the quadtree�s traditional square tessellation. In particular, the Hexagonal or Rhombus (HoR) quadtree designed by Bell et al. (1989) was used to programme TRUST v1.1. Using the HoR quadtree in rhombic mode (TRUST v1.1.1) produced Orbison�s optical illusion, so it was disregarded. However, the HoR trustree (the hexagonal tessellation produced by TRUST v1.1.2) was adopted for further research and user assessment. When assessed using an Internet survey, the HoR trustree adequately displayed choropleth spatial boundary uncertainty, but not attribute uncertainty. New trustree visualisations, the value-by-area (VBA) trustree and adjacent HoR trustree were developed to help increase the expression of attribute uncertainty. Upon reassessment, the new trustree visualisations were deemed usable to express attribute uncertainty and choropleth spatial boundary uncertainty at a modest 58% usable (HoR trustree), 80% usable (VBA trustree) and 85% usable (adjacent HoR trustree). A usability test (where participants were asked to spot different levels of uncertainty) validated these results, whereby the HoR trustree achieved a 65% accuracy level and the VBA trustree achieved an 80% accuracy level. The user assessments helped to highlight that the trustree could be used in two ways, to express detail within or clutter over areal units. The HoR trustree showed (1) a level of detail (or resolution) metaphor, where more detail represented more accuracy and/or the reverse, (2) a metaphor of clutter, where the data structure output was sufficiently dense as to cover spatial information, in effect hiding uncertain areas. Further Internet survey testing showed the trustree tessellation works better when representing a metaphor of detail. Attribute and spatial uncertainty can be effectively expressed depending on the tessellation level used. Overall, the new TRUST suite visualisations compare favourably with existing uncertainty visualisation techniques. Some uncertainty visualisation methods consistently performed better than the TRUST visualisations such as blinking areas, adjacent value and non-continuous cartograms. Other methods like colour saturation, image sharpness and a three-dimensional surface frequently performed with less usability. Therefore, the TRUST visualisations have found their place amongst other uncertainty visualisation methods. However, survey results showed that TRUST is a viable option for visualising two forms of uncertainty - attribute and spatial uncertainty. No other visualisation method has these capabilities. Further research could include a laboratory assessment of TRUST and also incorporating vagueness and temporal uncertainty concepts. Additionally, end-user testing could provide a valuable insight into uncertainty visualisation for everyday use. Adopting uncertainty methods to uncertainty, such as the technique presented here, into the mainstream decision making environment could be considered a fundamental objective for future investigation in spatial studies.

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Boessenkool, Sanne, i n/a. "Spatial and temporal genetic structuring in yellow-eyed penguins". University of Otago. Department of Zoology, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090812.163749.

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Improving our understanding of the forces driving population decline and the processes that affect the dynamics of threatened populations is central to the success of conservation management. The application of genetic tools, including our ability to examine ancient DNA, has now revolutionised our ability to investigate these processes. The recent human settlement of the Pacific, particularly in New Zealand, provides a unique, accessible system for revealing anthropogenic impacts on native biota. In this thesis I use genetic analyses from modern, historic and subfossil DNA to investigate temporal and spatial genetic structuring of the endangered yellow-eyed penguin (Megadyptes antipodes), and use these analyses to answer questions related to the conservation of this species. The yellow-eyed penguin is endemic to the New Zealand region and currently breeds on the subantarctic Auckland and Campbell Islands and the southeast coast of the South Island. The current total population size is estimated around 6000-7000 individuals, of which more than 60% inhabit the subantarctic. Despite intensive conservation measures by governmental and local community agencies, population sizes have remained highly unstable with strong fluctuations in numbers on the South Island. The species was believed to be more widespread and abundant before human colonisation of New Zealand, thus current management assumed the mainland population to be a declining remnant of a larger prehistoric population. Genetic and morphological analyses of subfossil, historic and modern penguin samples revealed an unexpected pattern of penguin extinction and expansion. Only in the last few hundred years did M. antipodes expand its range from the subantarctic to the New Zealand mainland. This range expansion was apparently facilitated by the extinction of M. antipodes' previously unrecognised sister species, M. waitaha, following Polynesian settlement in New Zealand. The demise of M. waitaha is the only known human-mediated extinction of a penguin species. Despite M. antipodes' recent range expansion, genetic analyses of microsatellite markers reveal two genetically and geographically distinct assemblages: South Island versus subantarctic populations. We detected only two first generation migrants that had dispersed from the subantarctic to the South Island, suggesting a migration rate of less than 2%. Moreover, the South Island population has low genetic variability compared to the subantarctic population. Temporal genetic analyses of historic and modern penguin specimens further revealed that the harmonic mean effective population size of the M. antipodes South Island population is low (<200). These findings suggest that the South Island population was founded by only a small number of individuals, and that subsequent levels of gene flow have remained low. Finally, we present a novel approach to detect errors in historic museum specimen data in cases where a priori suspicion is absent. Museum specimens provide an invaluable resource for biological research, but the scientific value of specimens is compromised by the presence of errors in collection data. Using individual-based genetic analysis of contemporary and historic microsatellite data we detected eight yellow-eyed penguin specimens with what appear to be fraudulently labelled collection locations. This finding suggests errors in locality data may be more common than previously suspected, and serves as a warning to all who use archive specimens to invest time in the verification of specimen data. Overall, yellow-eyed penguins have a remarkable dynamic history of recent expansion, which has resulted in two demographically independent populations. These results reveal that anthropogenic impacts may be far more complex than previously appreciated.

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Ates, Serkan. "Grazing management of subterranean clover (Trifolium subterraneum L.) in South Island (New Zealand)". Diss., Lincoln University, 2009. http://hdl.handle.net/10182/1338.

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This study consisted of two sheep grazed dryland pasture experiments. Experiment l compared sheep production from 3-year-old cocksfoot based pastures grown in combination with white, Caucasian, subterranean or balansa clover with a ryegrass-white clover pasture and a pure lucerne forage. Sheep liveweight gain per head from each pasture treatment and the pure lucerne stand was recorded in the 2006/07 and 2007/08 seasons. The cocksfoot-subterranean clover pasture provided equal (381 kg LW/ha in 2006) or higher (476 kg LW/ha in 2007) animal production in spring and gave the highest total animal production (646 kg LW/ha) averaged across years of the five grass based pastures. However, total annual liveweight production from lucerne was higher than any grass based pasture mainly due to superior animal production during summer when lucerne provided 42-85% higher animal production than any of the grass based pastures. In Experiment 2, the effect of stocking rate (8.3 (low) and 13.9 (high) ewes + twin lambs/ha) and time of closing in spring on lamb liveweight gain, pasture production and subterranean clover seedling populations was monitored over 2 years for a dryland cocksfoot-subterranean clover and ryegrass-subterranean clover pasture in Canterbury. In both years, twin lambs grew faster (g/head/d) in spring at low (327; 385) than high (253; 285) stocking rate but total liveweight gain/ha (kg/ha/d) was greater at high (7.26; 7.91) than low (5.43; 6.38) stocking rate. Ewes also gained 0.5 and 1.5 kg/head at the low stocking rate in 2006 and 2007 respectively but lost 0.2 kg/head in 2006 and gained 0.3 kg/head at high stocking rate in 2007. Mean subterranean clover seedling populations (per m²) measured in autumn after grazing treatments in the first spring were similar at both low (2850) and high (2500) stocking rate but declined with later closing dates in spring (3850, 2950, 2100 and 1700 at 2, 4, 6, 8 weeks after first visible flower). Seedling populations measured in autumn after grazing treatments in the second spring were also unaffected by stocking rate (low 1290, high 1190) but declined with later closing dates in spring (1470, 1320 and 940 at 3, 5 and 8 weeks after first flowering, respectively). The effect of stocking rate and closing dates in spring on pasture and clover production in the following autumn was similar to the effects on seedling numbers in both years. However, clover production in the following spring was unaffected by stocking rate or closing date in the previous year at the relatively high seedling populations generated by the treatments. This was presumably due to runner growth compensating for lower plant populations in pastures that were closed later in spring. Subterranean clover runner growth in spring may not compensate in a similar manner if seedling numbers in autumn fall below 500/m². Mean annual dry matter production from cocksfoot and ryegrass pastures grown with and without annual clovers pasture production ranged from 6.4 to 12.4 t DM/ha/y but stocking rate (8.3 vs. 13.9 ewes/ha) during spring did not affect annual pasture production. Pastures overdrilled with annual clovers yielded 23-45% more dry matter production than pastures grown without annual clovers. The study confirms the important role of subterranean clover in improving pasture production and liveweight gains of sheep in dryland cocksfoot and ryegrass pastures. Lowering stocking rate from 13.9 to 8.3 ewes/ha was a less effective method of increasing seed production of subterranean clover in dryland pastures although it did lead to increased liveweight gain per head.

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32

Brandt, Christopher Perry. "Past, Present and Future: An Examination of Quality of Life in New Zealand and the interRAI Quality of Life Survey". Thesis, University of Canterbury. Health Sciences Centre, 2010. http://hdl.handle.net/10092/5758.

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InterRAI is an internationally validated assessment tool used in many different contexts to assist different groups of people and patients to live fuller, safer and more productive lives. In 2008, the New Zealand Ministry of Health, after the completion a trial of the interRAI – Home Care assessment tool in the District Health Board, rolled out implementation of the interRAI – Home Care tool throughout New Zealand’s 21 District Health Boards. The Quality of Life survey itself is currently being assessed and trialled throughout the world as a follow-up to the Home Care assessment. It will enable researchers and assessors to enable for a comprehensive perspective by bringing together the views of both service providers and recipients of care service. The assessments will be completed by the person directly, as a self assessment, or through interview The overall research aim of the study itself is to evaluate the adequacy of the interRAI Quality of Life survey in assessing the Quality of Life issues and needs of the elderly living in their own homes in the community with some sort of publicly funded health care, social or community support such as meals on wheels, personal care, etc., for the purpose of demonstrating the importance of it as a useful tool within New Zealand. The objectives of the research are as follows: • Objective 1 - To review the management and application of quality of life indicators for the elderly. • Objective 2 – To understand the pressures which an ageing population places on public policy. • Objective 3 - To consider how quality of life measures can best be applied alongside interRAI in New Zealand. The research itself focused on the Quality of Life of thirty participants. Each participant was first assessed through an interRAI – HC assessment at their own home by an assessor from the Canterbury District Health Board. Upon completion of the assessment, they were given the option of being contacted by the researcher about participation in the interRAI Quality of Life Survey. Contact by the researcher by telephone ensued, which was then followed up by a face to face information session at the home of the participant. At this time, thirty out of thirty one potential participants decided to sign the informed consent form for participation. As the Quality of Life Survey itself is self reported, each participant was free to read through the survey and answer for themselves questions regarding their thoughts about their own quality of life. Participants responded to forty six statements from nine different domains on the Quality of Life Survey. Overall results showed a majority of responses of ‘Always’, which were positive. Areas of concern which emerged from the data were of possible issues of social isolation and unresolved emotional health. Limitations of the research included factors such as the small sample size of thirty, the geography of the study which was limited to Christchurch, and the fact that there was no follow up visit to the first and only interview. In conclusion, it is apparent that a larger trial throughout the District Health Board is required to overcome the aforementioned limitations of sample size and geography. Also, it is imperative that a follow-up visit is scheduled after the initial visit to allow for intervention into quality of life issues which emerge from the participant’s self-assessment.

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Parkkali, Seija Anna. "The role of natural selection and adaptation versus phenotypic plasticity in the invasive success of Hieracium lepidulum in New Zealand". Thesis, University of Canterbury. Biological Sciences, 2008. http://hdl.handle.net/10092/1799.

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Hieracium lepidulum is an invasive weed in New Zealand. It colonises a wide range of habitats including pine plantations, scrubland, native Nothofagus forest, and mid-altitude to alpine tussock grassland, where it is competing with indigenous species. Understanding the breeding systems and population genetic structure of H. lepidulum is important for biocontrol, and aids in the understanding of evolutionary colonisation processes. H. lepidulum is a triploid, diplosporous, obligate apomict. This type of reproduction through clonal seed does not involve meiosis or fertilisation, and theoretically populations should contain very low levels of genetic variation, the only source being somatic mutation. Common garden experiments and microsatellite markers were used to determine the population genetic structure of H. lepidulum populations in the Craigieburn Range, Canterbury. Both experiments revealed that populations, sampled from three replicate altitudes within three geographically-separated locations, contained no genetic variation; individuals all possessed the same microsatellite genotype. These results strongly suggest that the Craigieburn Range H. lepidulum individuals reproduce solely by apomixis and populations belong to the same clonal lineage. Populations were also examined for their response to two abiotic environmental ‘stresses’, drought and shade. H. lepidulum populations’ exhibited high drought tolerance, yet appeared to be shade-intolerant. Low levels of reproduction in light-limiting habitats will prevent the invasion of H. lepidulum into closed-canopy forest habitats. H. lepidulum appears to have overcome the reduction in fitness associated with apomictic reproduction by phenotypic plasticity, fixed heterozygosity and polyploidy – all associated with increased vigour, fitness, and the ability to occupy broader ecological niches. This study’s results are hopeful for the development of biocontrol programs involving genotype-specific pathogens but suggest that grazing management may not succeed. The data will be useful for future comparisons of genetic structure during the course of H. lepidulum invasions and will contribute to the management of this invasive weed.

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Keye, Constanze. "A study of home ranges, movement and activity patterns of Great Spotted Kiwi (Ateryx haastii) in the Hurunui Region, South Island, New Zealand". Lincoln University, 2008. http://hdl.handle.net/10182/1195.

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All kiwi species (Apteryx spp.) have suffered serious decline since human arrival and are nowa-days threatened on the New Zealand mainland. One of the most elusive, and as a result least known among the different kiwi species, is the great spotted kiwi (Apteryx haastii). Hence, little is known about the current status of the remaining great spotted kiwi populations or their popu-lation dynamics. Three main ‘natural’ populations are found in Northwest Nelson, the Paparoa Range and in the Arthur’s Pass Hurunui district. In 2007, the Department of Conservation started a great spotted kiwi population dynamics study in the North Branch of the Hurunui, the area where this research project was conducted. Kiwi workers of the Department of Conserva-tion (Waimakariri area office) captured and VHF radio-tagged 11 kiwi between March and July 2007 in the North Branch and started to collect radio tracking and activity data. To improve this existing data set, 10 of the 11 birds were intensely radio tracked using triangulation and homing techniques during December 2007 to April 2008 for this Master’s research project. Estimated home-range sizes for great spotted kiwi in the North Branch varied between 19.59 ha and 35.41 ha, with a calculated mean of 29.3 ha for adult birds. The kiwi population in a defined research area of 60 km² in the Hurunui North Branch was estimated to be around 290 birds. The density for the whole area monitored by the Department of Conservation in the North Branch was esti-mated to be 2.25 pairs per km² plus subadults or in other terms 4.83 birds per km². These density estimates are much higher than results of earlier studies in the Arthurs Pass/Hurunui district. Movement plots of three bonded pairs showed that partners stayed in territories they shared. Nevertheless pairs shared only in 5% of days (n=38) shelters but regularly met during night and kept in contact via calls especially prior to meetings. Nightly travel distances varied between 488-1657 m. Furthermore, the most frequent travel distances covered per hour ranged between 50-150 m. The results of this study provide information for other kiwi researchers and raise ad-ditional questions for other projects regarding great spotted kiwi biology, behaviour and dynam-ics still need to be answered (e.g. habitat requirements). Finally, the results of this study alone are poor indicators of current population health, but they do provide a scientific baseline for any subsequent population monitoring for the great spotted kiwi population status and health in the North Branch area. If future monitoring shows that the great spotted kiwi population is at risk, suitable management actions can be applied and their success can be correctly evaluated.

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Rynhart, Patrick Reuben. "Mathematical modelling of granulation processes : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Mathematical Physics at Massey University, Palmerston North, New Zealand". Massey University. Institute of Fundamental Sciences, 2004. http://hdl.handle.net/10179/242.

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Granulation is an industrial process where fine particles are bound together into larger granules. The process has numerous applications including the manufacture of pharmaceuticals and the production of cosmetics, chemicals, detergents and fertilisers. This thesis studies aspects of wet granulation which involves the application of a viscous binder, usually in the form of a spray, to an agitated bed of powder particles. Individual powder particles may adhere together, joined by small quantities of binder fluid called liquid bridges. By a process of collision and adherence additional particles may join the newly formed agglomerates. Agglomerates may also coalesce together which is a process that leads to granule formation. On the completion of this process, granules are typically dried.This thesis studies wet granulation on three different levels. First, micro-level investigations of liquid bridges between two and three particles are performed. For the two-particle case, the fluid profile of static (stationary) and dynamic (moving) liquid bridges is investigated. For the static case, a numerical solution to the Young-Laplace equation is obtained; this relates the volume of binder fluid to liquid bridge properties such as the inter-particle force. An analytic solution is also obtained, providing the liquid bridge profile in terms of known mathematical functions. For both solutions, the radii of the (spherical) primary particles may be different. The dynamic case is then studied using the Navier-Stokes equations with the low Reynolds number approximation. The motion of the approaching particles is shown to be damped by the viscosity of the liquid bridge. Static liquid bridges between three equally sized primary particles are then studied. Symmetry of the problem is used to obtain a numerical solution to the Young-Laplace equation. Liquid bridge properties are calculated in terms of the binder fluid volume. Experimental agreement is provided.Secondly, a model to estimate the stickiness (fractional wet surface area) of agglomerates is proposed. Primary particles are approximated as spheres and are added one at a time in a closely packed arrangement. The model includes parameters to control the inter-particle separation distance and the fluid saturation state. Computational geometry is used to obtain results which relate the number of particles and the volume of binder fluid to the stickiness of the agglomerates.Finally, a population balance model for wet granulation is developed by extending an earlier model to incorporate the effects of binder fluid. Functions for the inter-particle collision rate and drying rate are proposed, including functions which are derived from the geometric model, described above, for the case of maximum particle consolidation. The model is solved numerically for a range of coalescence kernels and results are presented which show the effect of binder volume and the drying rate.

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Vargas, Mariana L. "Host-parasite coevolution in New Zealand: how has Odontacarus, a mite with a free-living stage in its life-cycle, coevolved with its skink host?" Lincoln University, 2006. http://hdl.handle.net/10182/1072.

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The effect of a free-living stage in host-parasite coevolution: a skink mite phylogenetic study in New Zealand. During the last decade, phylogenetic trees have even been used to compare ecologically related taxa such as parasites and their hosts, and are used to determine their level of coevolution or reciprocal adaptation in time. Diverse coevolutionary events have been detected for this ecological association, where generally the parasite has been regarded as one that feeds exclusively on the host and is likely to cospeciate with it. A different coevolutionary pattern might occur when the parasite has a free-living stage in its life cycle, in which the parasite may have the opportunity to abandon its host and successfully colonise a new species (host-switching) making cospeciation less likely. Many New Zealand skinks are infested with a parasitic mite, Odontacarus sp. (Prostigmata: Leeuwenhoekiidae), which becomes free-living as an adult. The genetic variation of these mites found on four hosts was analyzed for host- parasite coevolutionary events. The hosts were the McCann’s skink and the common skink in coastal Birdling Flat, Canterbury, plus these species and the Grand and Otago skinks in Macraes Flat, Central Otago, South Island, New Zealand. The genetic variation of fast evolving nuclear Internal Transcribed Spacers 2 and mitochondrial Cytochrome c Oxidase I in Odontacarus mites found on these hosts was determined by PCR and DNA sequencing and phylogenetic trees were built using the computer programs PAUP*4 and MrBayes 3. The results show that mite haplotypes only had a significant geographical division and no host-related differences. In Birdling Flat, the COI haplotypes were represented in two groups that infested both regional hosts and had 5.7 % divergence. The same individual mites belonged to a single ITS 2 haplotype, thus indicating a historical geographical division between two populations that now interbreed successfully. The Macraes Flat mites were divided into two COI haplotypes with 2.4% divergence and internal nodes, which showed greater genetic variability than the Birdling Flat populations. The Macraes Flat mites formed two ITS 2 haplotypes with 6% divergence. This greater geographical structure of the Otago mites is probably due to the older age of the mainland area compared to the recently exposed coastal locality of Birdling Flat. The COI haplotypes from the two different regions had a mean distance of 15.5%, with an earlier divergence time than that known for the hosts. For both genes, the haplotypes from different regions had 100% bootstrap support and the parasite showed no host specificity. Mites of the different COI and ITS haplotypes were found on most of the host species that were sampled in Canterbury and Otago. The results of this study suggest that a free-living stage in a parasite’s life cycle can favour coevolutionary events such as inertia (failure to speciate) and host-switching, probably as a result of resource-tracking of the parasite. NB: Electronic files contained on CD to accompany print copy are not included with this version of the thesis.

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Burrows, Ben Robert. "Do Severe Genetic Bottlenecks Lead to Greater Reproductive Failure?" Thesis, University of Canterbury. Biological Sciences, 2006. http://hdl.handle.net/10092/1344.

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It is generally accepted that populations which experience severe bottlenecks have a reduction in fitness. One of the most frequently reported fitness costs is increased hatching failure in bottlenecked populations of birds. The mechanism responsible for increased hatching failure is unknown. Research on other animals suggest that reduced population numbers cause unavoidable inbreeding that in turn leads to abnormalities in the gametes. In this thesis I examine some of the possible causes for increased hatching failure in severely bottlenecked populations of introduced birds in New Zealand. I look at three traits identified as a cause for infertility or hatching failure previously and determine whether there is a link with the size of a population s bottleneck. It is possible that reduced numbers of sperm reaching the site of fertilisation is a primary cause of hatching failure. I examined the perivitelline membrane of various species of introduced birds and counted the total number of sperm present to compare to how many would be expected in non-bottlenecked species. Although there was no relationship between the size of the bottleneck and the number of sperm present, all species had lower than expected sperm counts. In many species of mammals, a reduction in the quality of sperm is attributed to inbreeding depression bought about by genetic bottlenecks. I next compared the level of sperm abnormalities, variation in midpiece size sperm, and sperm motility with the size of the bottleneck each species passed through when introduced to New Zealand. There was no significant correlation between either the variation in midpiece size or sperm motility with bottleneck size. However, there was a trend for species that passed through more severe bottlenecks to have a slightly higher level of midpiece size and lower motility. Finally, I examined whether there was a link between abnormalities in the eggshell and the size of the respective bottleneck. There was no significant change in eggshell thickness or any change in the number of pores associated bottleneck size. However, there was a decreased number of round pores in severely bottlenecked species, although the consequences of this are unknown. My findings do not directly link a single cause for increased hatching failure in bottlenecked species of birds, but they do highlight the need for monitoring of reproductive traits in endangered species that have experienced a population bottleneck.

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38

McDonald, Amy Elizabeth. "Improving the success of a translocation of black mudfish (Neochanna diversus)". The University of Waikato, 2007. http://hdl.handle.net/10289/2345.

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All of New Zealand's five endemic species of mudfish (Neochanna) are threatened, and translocation has been recommended as an option for conservation. This research undertakes a translocation of black mudfish (Neochanna diversus) into wetland margins of Lake Kaituna, in the Waikato region, and addresses research questions applicable to improving translocation success. Results from this research are intended to aid possible future translocations of the more threatened Northland mudfish (Neochanna heleios) and other genetically distinct populations of black mudfish. Captive rearing of juveniles collected from the wild is currently the most feasible option for sourcing translocation stock. Mudfish juveniles (greater than 25 mm T.L.) had greater survival rates, compared to mudfish fry less than 25 mm T.L. Mudfish growth was far greater when fed on a combined diet of brine shrimp (Artemia salina) and white worms (Enchytraeus albidus) than when fed exclusively on brine shrimp. Temperature was found to have a small effect on mudfish growth, with a slightly greater growth in fish at 15 C than those at 10 C. The introduced species Gambusia affinis has been the subject of concern for mudfish conservation and commonly found at wetland sites suitable for mudfish translocation. Found to prey on mudfish fry and eggs in aquaria, it was important to determine the effects of Gambusia density prior to undertaking a translocation to a location where Gambusia were present. Investigations were made into the effect of Gambusia density on black mudfish juveniles in 9 outdoor mesocosms. Increasing Gambusia density was found to have an inhibitory effect on black mudfish growth. This may be due to increased competition for food, a theory supported by analysis of zooplankton communities, where, in the presence of Gambusia, large zooplankton had been removed and smaller rotifers flourished. Monitoring programmes are required to assess any impacts or improvements of mudfish populations, including those created by translocation. A Gee minnow trapping programme in outdoor mesocosms was conducted to test the reliability of traps, finding that water depth, mudfish density, mudfish memory and trap shyness had no effect on the trapability of mudfish. Trap position was found to have the most significant effect, with a greater number of mudfish caught when traps were set overnight at the surface than when set on the bottom of mesocosms. Black mudfish adults and juveniles were translocated into 18 pools (~1 m diameter) on the wetland margins of Lake Kaituna in September 2006, followed by monthly monitoring. Water quality monitoring and an assessment of hydrology and vegetation was undertaken. Habitat characterisation was found to be a key factor, with correlations between water quality data and trapping results finding fewer fish remaining in pools with less suitable characteristics for mudfish (e.g. high turbidity and conductivity). Other species were found to have a large impact, with predation by shortfinned eels (Anguilla australis) thought to have eliminated mudfish from some pools. In addition fewer mudfish were caught in pools with Gambusia, possibly due to increased competition.

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39

Thompson, Kirsten Freja. "Secrets of the deep : the molecular genetics of cryptic beaked whales". Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/27760.

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Beaked whales are comparatively unknown social mammals due to their deep-ocean distribution and elusive habits. The deep-ocean is the largest biome on Earth and the final frontier for human expansion. Since their first discovery, beaked whales have remained largely hidden from science. In this era of rapid technological advancement, genetic and genomic methods are key tools for population biologists and are particularly useful in describing rarely seen species. Using DNA-barcoding and nuclear markers, the publications in this thesis provide data on the distribution and external appearance of two species of beaked whale: the spade-toothed (Mesoplodon traversii) and Derinayagala’s whale (Mesoplodon hotaula). These whales were previously known from only a handful of tissue and bone specimens. Long-term efforts have facilitated the collection of samples of Gray’s beaked whale (Mesoplodon grayi) and we have used shot-gun sequencing to characterise the mitochondrial genome and isolate species-specific nuclear microsatellite loci. Using genetic species and sex identification, together with museum specimens and multivariate analyses, we provide clear evidence of sexual dimorphism in cranial dimensions and geographic variation in external morphology. No genetic differentiation was evident in Gray’s beaked whales across a large study area (~ 6,000 km). With a large female effective population size (Ne) and genetic homogeneity, we hypothesise that gene flow is facilitated by large-scale oceanographic features, such as the sub-tropical convergence. Genetic kinship analyses within Gray’s beaked whale groups suggest that the whales that strand together are not related. Both sexes disperse from their parents and these groups are not formed through the retention of kin. These results are consistent with a ‘fission-fusion’ social system that has been observed in some oceanic dolphin species. Taken together, these data provide the first insights into the population dynamics, dispersal and social organisation in Gray’s beaked whales. These publications highlight the value of using genetics alongside other techniques to describe inter- and intraspecific diversity. For beaked whales, the dead can tell us much about the living.

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40

Schmechel, Frances A. "Aspects of habitat selection, population dynamics, and breeding biology in the endangered Chatham Island oystercatcher (Haematopus chathamensis)". Lincoln University, 2001. http://hdl.handle.net/10182/1814.

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In the late 1980s the endangered Chatham Island oystercatcher (Haematopus chathamensis) (CIO) was estimated at less than 110 individuals. Endemic to the Chatham Islands, New Zealand, it was feared to be declining and, based on existing productivity estimates, in danger of extinction within 50-70 years. These declines were thought to be caused by numerous changes since the arrival of humans, including the introduction of several terrestrial predators, the establishment of marram grass (Ammophila arenaria) which changes dune profiles, and increased disturbance along the coastline. The New Zealand Department of Conservation has undertaken recovery planning and conservation management to increase CIO numbers since the late 1980s. Recovery planning raised some key research questions concerning the population dynamics, habitat selection, and breeding biology of Chatham Island oystercatcher (CIO), and the critical factors currently limiting the population. The objectives of this study were to collect and interpret data on: 1) population size, trends, and distribution across the Chathams, 2) basic breeding parameters, 3) recruitment and mortality rates, 4) habitat selection at the general, territorial and nest-site levels, 5) habitat factors that are correlated with territory quality, and 6) cues that elicit territorial behaviour in CIO.

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41

Will, Margaret. "Genetic variation in New Zealand abalone, Haliotis iris". Thesis, University of Canterbury. School of Biological Sciences, 2009. http://hdl.handle.net/10092/4418.

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Abalone (Haliotis spp.) are marine broadcast spawners that inhabit temperate and tropical waters across the globe. Their importance as a fisheries resource has resulted in considerable research into key aspects of their biology, particularly around growth and reproduction. In addition, there has been ongoing interest regarding the genetic variation in both wild and hatchery populations. The majority of abalone dispersal probably occurs during a pelagic lecithotrophic larval stage. In general, oceanographic features, life history characteristics, and larval dispersal ability can manipulate dispersal and gene flow patterns of marine fauna. In the case of abalone, considerable research has examined the population genetic structure of a variety of species, and several papers implicate ocean currents and life history characteristics as important factors that define population genetic structure. In comparison to other abalone species, little information regarding the genetic structure of New Zealand's endemic H. iris exists. The goal of this thesis was to elucidate the genetic structure of H. iris using mitochondrial and nuclear markers in regards to two potential barriers to gene flow, the Cook Strait region and the gamete recognition protein, lysin. The genetic structure of H. iris was first examined in regards to a consistent pattern of genetic structure emerging in recent literature of coastal marine invertebrates around New Zealand: specifically, a north-south genetic split that occurs in the Cook Strait region (Chapter 2). Two regions of the mitochondria (totaling 1055 bp) were amplified across 477 individuals from 25 locations around New Zealand. A north-south split around the Cook Strait region was evident among H. iris samples. Unlike the other studies of New Zealand coastal marine invertebrates, the north-south split for H. iris was not located across regions of reported upwelling; instead the split was located across Cook Strait narrows. The north-south split was reflected in increased haplotype diversity for the northern samples. Genetic structure was also examined using microsatellite loci. After unsuccessful attempts at cross-species amplification using 8 loci developed for H. rubra and 11 loci developed for H. midae, 13 polymorphic loci were isolated de novo for H. iris (Chapter 3). Of these, three very polymorphic loci were optimized for population genetic analyses. These three loci were used to genotype 447–459 individuals from the same 25 locations examined with mitochondrial DNA (Chapter 4). Like the mitochondrial DNA, the microsattelites indicated population genetic structure around the Cook Strait region; however the split identified with microsatellites occurred in the greater Cook Strait region with two sample sites from the north of the South Island grouping with the North Island. Extrinsic barriers, like the Cook Strait region, are the primary focus of studies examining differentiation in marine invertebrate fauna. However, dispersal of an individual to a new population does not necessarily mean it can successfully reproduce with individuals of the new population. Potentially, populations may be diverging at genes essential for reproduction, i.e. gamete recognition proteins. The abalone egg recognition protein, lysin, is one of the best characterized gamete recognition proteins in marine broadcast spawners. Despite its well-understood function and structure, studies examining variation in lysin have been limited to small sample sizes (N ≤ 11) and have found very little variation. Here, lysin was screened across 287 individuals from 17 sampling sites around New Zealand to assess intraspecific variation and genetic structure across the Cook Strait region (Chapter 5). The majority of the variation in a 783 bp fragment spanning from exon 4 to 5, was located in the intron. The variability in this fragment detected no genetic structure among samples or across the Cook Strait region. The variation in lysin was considerably lower than the variation in either the mitochondrial DNA or the microsatellite loci. To determine whether this was an artifact of being a nuclear sequence, which, in general, have a lower mutation rates than microsatellite markers and mitochondrial DNA and a larger effective population size then mitochondrial DNA, or was a signature of a recent selective sweep, 857 bp of the Gα1 intron was assessed for genetic variation in 227 H. iris individuals from 14 sampling locations (Chapter 6). The Gα1 intron was considerably more diverse than the lysin fragment examined, suggesting that the relative lack of variation in the lysin fragment has resulted from a recent selective sweep. Additionally, the Gα1 intron was used to examine population genetic structure across the Cook Strait region and detected a weak but significant pattern of structure consistent with that detected using the microsatellite loci. Overall, the a priori tests of genetic structure based on mitochondrial DNA, microsatellite markers, and the across Gα1 intron all identified a north-south genetic split around the Cook Strait region; however, the patterns of this split was slightly inconsistent among molecular markers. When cluster analyses were applied the patterns of genetic structure became more similar: for the mitochondrial, microsatellite, and Gα1 intron data, cluster analyses indicate that only one sample from the north of the South Island groups with the North Island, while a few discrepancies existed in regards the grouping of samples from the east coast of the North Island.

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42

Tocher, Mandy Darlene. "The New Zealand common gecko Hoplodactylus maculatus: an ecophysiological comparsion of two isolated populations". Thesis, University of Canterbury. Biological Sciences, 1992. http://hdl.handle.net/10092/1431.

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Thermophysiological traits of two isolated Hoplodactylus maculatus populations were investigated to test adpatations to climate. Geckos were collected from Craigieburn (high altitude, generally cooler site) and Banks Peninsula. If climatic conditions at respective sites influenced physiology, I expected geckos from Craigieburn to exhibit cold-adapted physiological traits, whilst Banks Peninsula geckos would exhibit traits more characteristic of a warmclimate species. To this end I investigated four thermophysiological parameters: metabolism (SMR), preferred body temperature (PBT), locomotory performance and critical thermal minimum (CTMin). I hypothesized that if climate had an effect on SMR, Craigieburn geckos would exhibit higher levels of SMR which typically characterise other coolclimate reptiles. Craigieburn geckos displayed an average relative elevation of SMR over Banks Peninsula geckos of 26%. Furthermore, Craigieburn geckos appeared to be 'geared' towards lower body temperatures and exhibited a greater acclimatory and acclimatizatory ability of SMR. The PBT of Craigieburn geckos was consistently elevated above Banks Peninsula geckos. This finding was somewhat paradoxical in light of previous studies of this parameter. A closer examination of the ecology of the two populations is required to clarify the adaptive significance of a higher PBT in geckos from a cooler climate. With respect to locomotory performance, I hypothesized that if thermal extremes influenced activity, Craigieburn geckos would exhibit activity patterns which help ameliorate the adverse effects of cold temperature. Craigieburn geckos did in fact have greater independence of activity to temperature than Banks Peninsula geckos, especially over lower body temperatures. The final parameter investigated, that of the critical thermal minimum, failed to distinguish the populations decisively. However there was some evidence of a greater acclimatizatory and acclimatory range in Craigieburn geckos, providing somewhat limited support for a population difference. Investigations into all four parameters lead me to conclude that populations of Hoplodactylus maculatus from Craigieburn and Banks Peninsula are physiologically distinct and warrant a revision of nomenclature.

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43

Barron, M. C. "Population ecology of the red admiral butterfly (Bassaris gonerilla) and the effects of non-target parasitism by Pteromalus puparum". Lincoln University, 2004. http://hdl.handle.net/10182/1763.

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There is anecdotal evidence that populations of the New Zealand endemic red admiral butterfly Bassaris gonerilla (F.) have declined since the early 1900s. This decline has been associated with the introduction of the generalist pupal parasitoids Pteromalus puparum (L.) and Echthromorpha intricatoria (F.). The former was deliberately introduced for the biological control of the cabbage white butterfly (Pieris rapae (L.)); the latter is an adventitious arrival from Australia. The objective of this thesis was to quantify, using population models, the effect that P. puparum is having on B. gonerilla abundance. Population monitoring and a phenology model (based on temperature-related development rates) indicated that B. gonerilla has two full generations and one partial generation per summer in the Banks Peninsula region of New Zealand. B. gonerilla abundance was greatly reduced in drought summers, which was probably due to the negative effects of drought on the quality and quantity of the larval host plant Urtica ferox Forst. A life table study showed that egg parasitism by the unidentified scelionid Telenomus sp. was the largest mortality factor for the pre-imaginal stages of B. gonerilla, followed by "disappearance" mortality (predation and dispersal) in the larval stages. Pupal mortality due to P. puparum was lower compared with that caused by E. intricatoria, with 1-19% and 20-30% of pupae being parasitised by P. puparum and E. intricatoria, respectively. Collection of B. gonerilla pupae from the Christchurch, Dunedin and Wellington areas confirmed higher rates of percentage parasitism by E. intricatoria. B. gonerilla collected from the Banks Peninsula had a 50: 50 sex ratio and lifetime fecundity was estimated in the laboratory as 312 eggs per female. There was no evidence of density-dependent parasitism of B. gonerilla pupae by P. puparum in the field, although there was a significant positive relationship between life table estimates of E. intricatoria parasitism and B. gonerilla pupal abundance. Larval dispersal from the host plant showed a positive relationship with larval instar but no relationship with larval density. Rates of change in B. gonerilla adult abundance between generations within a year showed evidence of density dependence, and this negative feedback was stronger in a drought year. A discrete-time model for B. gonerilla population dynamics was constructed which had two summer generations per year and a partial overwintering generation. The model showed that the presence of this overwintering generation provides a temporal refuge from high levels of E. intricatoria parasitism. Removal of parasitoid mortality from the model suggested that P. puparum was suppressing B. Gonerilla populations on the Banks Peninsula by 5% and E. intricatoria by 30%. An important assumption of the model was that parasitism rates were independent of B. gonerilla density. This assumption appears valid for P. puparum parasitism, but may not be valid for E. intricatoria; therefore the estimated suppression levels due to this adventive parasitoid should be viewed with some caution. It is too soon to generalise on what determines the magnitude of non-target effects by arthropod biocontrol agents, this being only the second study to quantify effects at a population level. However, in this case retrospective analysis has shown that the impact of non-target parasitism by P. puparum on B. gonerilla abundance has been small. There is anecdotal evidence that populations of the New Zealand endemic red admiral butterfly Bassaris gonerilla (F.) have declined since the early 1900s. This decline has been associated with the introduction of the generalist pupal parasitoids Pteromalus puparum (L.) and Echthromorpha intricatoria (F.). The former was deliberately introduced for the biological control of the cabbage white butterfly (Pieris rapae (L.)); the latter is an adventitious arrival from Australia. The objective of this thesis was to quantify, using population models, the effect that P. puparum is having on B. gonerilla abundance. Population monitoring and a phenology model (based on temperature-related development rates) indicated that B. gonerilla has two full generations and one partial generation per summer in the Banks Peninsula region of New Zealand. B. gonerilla abundance was greatly reduced in drought summers, which was probably due to the negative effects of drought on the quality and quantity of the larval host plant Urtica ferox Forst.. A life table study showed that egg parasitism by the unidentified scelionid Telenomus sp. was the largest mortality factor for the pre-imaginal stages of B. gonerilla, followed by "disappearance" mortality (predation and dispersal) in the larval stages. Pupal mortality due to P. puparum was lower compared with that caused by E. intricatoria, with 1-19% and 20-30% of pupae being parasitised by P. puparum and E. intricatoria, respectively. Collection of B. gonerilla pupae from the Christchurch, Dunedin and Wellington areas confirmed higher rates of percentage parasitism by E. intricatoria. B. gonerilla collected from the Banks Peninsula had a 50: 50 sex ratio and lifetime fecundity was estimated in the laboratory as 312 eggs per female. There was no evidence of density-dependent parasitism of B. gonerilla pupae by P. puparum in the field, although there was a significant positive relationship between life table estimates of E. intricatoria parasitism and B. gonerilla pupal abundance. Larval dispersal from the host plant showed a positive relationship with larval instar but no relationship with larval density. Rates of change in B. gonerilla adult abundance between generations within a year showed evidence of density dependence, and this negative feedback was stronger in a drought year. A discrete-time model for B. gonerilla population dynamics was constructed which had two summer generations per year and a partial overwintering generation. The model showed that the presence of this overwintering generation provides a temporal refuge from high levels of E. intricatoria parasitism. Removal of parasitoid mortality from the model suggested that P. puparum was suppressing B. Gonerilla populations on the Banks Peninsula by 5% and E. intricatoria by 30%. An important assumption of the model was that parasitism rates were independent of B. gonerilla density. This assumption appears valid for P. puparum parasitism, but may not be valid for E. intricatoria; therefore the estimated suppression levels due to this adventive parasitoid should be viewed with some caution. It is too soon to generalise on what determines the magnitude of non-target effects by arthropod biocontrol agents, this being only the second study to quantify effects at a population level. However, in this case retrospective analysis has shown that the impact of non-target parasitism by P. puparum on B. gonerilla abundance has been small.

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Bridgman, John B., i n/a. "Intercanthal and interpupillary distance in New Zealand Maori and Samoan populations". University of Otago. School of Dentistry, 1999. http://adt.otago.ac.nz./public/adt-NZDU20070524.122205.

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New Zealand Maori and Pacific Island ethnic groups are marking up an increasingly larger proportion of New Zealand�s population. Intercanthal distance (ICD) and management of congenital and acquired deformities of the craniofacial complex. The ICD and IPD have been found to differ to establish these measurements for New zealand Maori and Samoan populations. For New Zealand Maori males the mean ICD was 32.1mm with a standard deviation (SD) of 2.6mm, and the mean IPD was 63.3mm, SD 3.8mm. For New Zealand Maori females the mean ICD was 30.7mm, SD2.7mm and the mean IPD was 60.1mm, SD2.8mm. For Samoan males the mean ICD was 33.9mm, SD2.5mm and the mean IPD 64.5mm, SD3.5mm. For Samoan females the mean ICD was 32.9mm, SD2.3mm and their mean IPD was 61.7mm, SD2.8mm. Consistent with other ethnicities New Zealand Maori and Samoan males have wider values for ICD and IPD than females respectively. New Zealand Maori measurements tend to lie within the normal values established for Caucasian populations, whilst Samoans have larger values.

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Krosch, Matthew Neil. "Evolutionary biology of Gondwanan non-biting midges (Diptera: Chironomidae)". Thesis, Queensland University of Technology, 2010. https://eprints.qut.edu.au/41749/1/Matthew_Krosch_Thesis.pdf.

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The potential restriction to effective dispersal and gene flow caused by habitat fragmentation can apply to multiple levels of evolutionary scale; from the fragmentation of ancient supercontinents driving diversification and speciation on disjunct landmasses, to the isolation of proximate populations as a result of their inability to cross intervening unsuitable habitat. Investigating the role of habitat fragmentation in driving diversity within and among taxa can thus include inferences of phylogenetic relationships among taxa, assessments of intraspecific phylogeographic structure and analyses of gene flow among neighbouring populations. The proposed Gondwanan clade within the chironomid (non-biting midge) subfamily Orthocladiinae (Diptera: Chironomidae) represents a model system for investigating the role that population fragmentation and isolation has played at different evolutionary scales. A pilot study by Krosch et al (2009) indentified several highly divergent lineages restricted to ancient rainforest refugia and limited gene flow among proximate sites within a refuge for one member of this clade, Echinocladius martini Cranston. This study provided a framework for investigating the evolutionary history of this taxon and its relatives more thoroughly. Populations of E. martini were sampled in the Paluma bioregion of northeast Queensland to investigate patterns of fine-scale within- and among-stream dispersal and gene flow within a refuge more rigorously. Data was incorporated from Krosch et al (2009) and additional sites were sampled up- and downstream of the original sites. Analyses of genetic structure revealed strong natal site fidelity and high genetic structure among geographically proximate streams. Little evidence was found for regular headwater exchange among upstream sites, but there was distinct evidence for rare adult flight among sites on separate stream reaches. Overall, however, the distribution of shared haplotypes implied that both larval and adult dispersal was largely limited to the natal stream channel. Patterns of regional phylogeographic structure were examined in two related austral orthoclad taxa – Naonella forsythi Boothroyd from New Zealand and Ferringtonia patagonica Sæther and Andersen from southern South America – to provide a comparison with patterns revealed in their close relative E. martini. Both taxa inhabit tectonically active areas of the southern hemisphere that have also experienced several glaciation events throughout the Plio-Pleistocene that are thought to have affected population structure dramatically in many taxa. Four highly divergent lineages estimated to have diverged since the late Miocene were revealed in each taxon, mirroring patterns in E. martini; however, there was no evidence for local geographical endemism, implying substantial range expansion post-diversification. The differences in pattern evident among the three related taxa were suggested to have been influenced by variation in the responses of closed forest habitat to climatic fluctuations during interglacial periods across the three landmasses. Phylogeographic structure in E. martini was resolved at a continental scale by expanding upon the sampling design of Krosch et al (2009) to encompass populations in southeast Queensland, New South Wales and Victoria. Patterns of phylogeographic structure were consistent with expectations and several previously unrecognised lineages were revealed from central- and southern Australia that were geographically endemic to closed forest refugia. Estimated divergence times were congruent with the timing of Plio-Pleistocene rainforest contractions across the east coast of Australia. This suggested that dispersal and gene flow of E. martini among isolated refugia was highly restricted and that this taxon was susceptible to the impacts of habitat change. Broader phylogenetic relationships among taxa considered to be members of this Gondwanan orthoclad group were resolved in order to test expected patterns of evolutionary affinities across the austral continents. The inferred phylogeny and estimated divergence times did not accord with expected patterns based on the geological sequence of break-up of the Gondwanan supercontinent and implied instead several transoceanic dispersal events post-vicariance. Difficulties in appropriate taxonomic sampling and accurate calibration of molecular phylogenies notwithstanding, the sampling regime implemented in the current study has been the most intensive yet performed for austral members of the Orthocladiinae and unsurprisingly has revealed both novel taxa and phylogenetic relationships within and among described genera. Several novel associations between life stages are made here for both described and previously unknown taxa. Investigating evolutionary relationships within and among members of this clade of proposed Gondwanan orthoclad taxa has demonstrated that a complex interaction between historical population fragmentation and dispersal at several levels of evolutionary scale has been important in driving diversification in this group. While interruptions to migration, colonisation and gene flow driven by population fragmentation have clearly contributed to the development and maintenance of much of the diversity present in this group, long-distance dispersal has also played a role in influencing diversification of continental biotas and facilitating gene flow among disjunct populations.

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46

Thurmond, Thane S. "Indomethacin Reduces Splenic Red Pulp Macrophage Populations in Female New Zealand White Rabbits". Digital Commons @ East Tennessee State University, 1995. https://dc.etsu.edu/etd/2807.

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In an effort to elucidate the mechanism by which indomethacin (IN) attenuates the stimulatory effect of estradiol (E$\sb2$) on rabbit splenic red pulp macrophages (RPM), thirty-nine female New Zealand White rabbits were divided into 10 groups: ovariectomized (OVX), OVX/IN at 0.1 and 5.0 mg/kg body weight (bw)/day; sham OVX (SOVX), SOVX/IN at 0.1 and 5.0 mg/kg bw/day; OVX/25 mg E2, OVX/25 mg E$\sb2$/IN at 0.1 and 5.0 mg/kg bw/day; intact Control. Quantitative changes in RPM population in response to the treatments were measured using a 0 to 4 histologic grading scale. Estradiol treatment resulted in increased RPM grade when compared to the OVX non-E$\sb2$ groups. Indomethacin addition decreased mean RPM grade in the SOVX/IN 5.0 group when compared to its E$\sb2$ control group. Indomethacin administration had no significant effect on levels of PGE$\sb2$ in the spleen, blood or urine (p $>$.05). Hematocrits were reduced in both OVX and OVX/E$\sb2$ groups and this decrease was exacerbated by the high IN dose. The results from this study suggest that the effect of IN on E$\sb2$-induced RPM activation may be mediated through a non-prostaglandin pathway. The observed hematocrit changes are possibly the result of direct action of IN and E$\sb2$ on erythrocytes. To further investigate whether a direct interaction of IN and E$\sb2$ with rabbit erythrocytes may be responsible for the decreases in hematocrit observed in vivo, an in vitro study was conducted to determine the effect of these drugs on erythrocyte fragility characteristics. Two ml aliquots of treated New Zealand White rabbit whole blood were assayed as; Control, IN (9.6 $\mu$g/ml), E$\sb2$ (500 pg/ml) and IN plus E$\sb2$, for changes in erythrocyte fragility. Osmotic (OF) and mechanical (MF) fragility were evaluated under approximate physiological conditions by measurement of hemoglobin release at 545 nm. Blood samples at 39.5$\sp\circ$C were assayed immediately after drug addition (initial) and again 4 hours after incubation (final). Eight replicates of each experiment were run. Results of the OF assays showed a significant increase (p $<$.05) in mean 50% hemolysis point between IN (final) and IN plus E$\sb2$ (final) when compared to their mean initial values and to the mean final Control value. The OF hemolysis dispersion was increased by IN and IN plus E$\sb2$ treatment when final values were compared to initial values. The mean final values for MF increased with IN, E$\sb2$ and IN plus E$\sb2$ treatment versus the mean final Control value (p $<$.05). While the increase in MF from IN was greater than that from E$\sb2$, the MF from the combination (IN plus E$\sb2$) was not greater than from IN alone (p $>$.05). The IN-induced increases in both OF and MF indicate a difference in degrees of interaction with the erythrocyte from that of E$\sb2$, which only affected MF and whose effect was not additive or synergistic with that of IN. The in vitro experimental results demonstrate that the increased fragility produced by IN and E$\sb2$ on rabbit erythrocytes may account for the observed in vivo reduction in hematocrit. Increased erythrocyte fragility would also lead to their accelerated clearance from the circulation by splenic RPM and subsequent increases in activity of these macrophages. This elevation in splenic RPM population may also be enhanced by direct E$\sb2$ stimulation of macrophage proliferation.

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47

McClellan, Rachel Katherine, i n/a. "The ecology and management of Southland's black-billed gulls". University of Otago. Department of Zoology, 2009. http://adt.otago.ac.nz./public/adt-NZDU20090827.110233.

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The black-billed gull (Larus bulleri) is a small gull that nests in dense colonies on gravel-bedded rivers in southern New Zealand. This dissertation describes research undertaken in Southland in 2004-2006 that investigates black-billed gull population decline and its causes. Historical ground counts of nests were calibrated with aerial photography of colonies and population trends analysed. The decline in breeding birds on Southland's four main rivers was equivalent to 6.0%/year (SE 1.8) or 83.6% in 30 years justifying the species' present listing as Endangered. Aerial monitoring is a poor index of the breeding population and major temporal variation was identified in counts. All re-sighted second-year birds exhibited natal dispersal and -70% left the natal catchment. Forty one percent of birds banded as adults also dispersed to other catchments. Breeding dispersal is apparently unrelated to previous breeding success and the availability of the previous year's colony site, and dispersing birds did not move as groups. Southland's black-billed gulls constitute a single inter-mixing population. Black-billed gulls selected sites on islands and banks according to availability, and selected rivers consistent with the number of gravel patches. Site vulnerability to floods varied significantly. Re-use of colony sites was positively influenced by use in previous years, the extraction of gravel, site stability and low weed cover. Widespread introduced weeds on colony sites preventing nesting and may have increased flooding risk. Colony size was related to colony area, which was related to gravel patch size. Investigation of historical changes in breeding habitat availability in Southland indicated a major reduction in gravel habitat on the Lower Oreti River between 1976 and 2002 due to river works including gravel extraction. On the Waiau River, Manapouri Dam construction in 1970 initially increased gravel areas, since reversed in the mid Waiau, and caused a 75% decline in the number of islands. Gravel patch sizes are still declining on the Lower Oreti and possibly the Mid Waiau. Hundreds of gravel patches remain on Southland rivers. Over 5000 nests in 21 colonies were monitored during incubation. Colony nest success was most influenced by colony location, averaging 90.1% (SE 2.1) on islands within rivers, and 66.8% (SE 2.2) on riverbanks, indicating that terrestrial predators exert the greatest influence on productivity. Breeding success, the mean number of fledglings produced per nest by colony, varied between 0 and 0.88 fledglings (mean 0.32, SE 0.08). Both parameters were positively related to colony size. The three smallest colonies failed to breed successfully, suggesting the presence of an Allee effect. Deterministic matrix models were used to investigate population trends using survival and productivity estimates for the closely related Kaikoura red-billed gull (L. novaehollandiae scopulinus). Adult survival, followed by breeding success and survival of first year birds, had the greatest influence on population projections. Improvements in most parameters are probably required to reverse the decline of Southland's black-billed gulls. Predation and disturbance by introduced mammals and the native black-backed gull (L. dominicanus) had the greatest impact on black-billed gull productivity. Most human disturbance is insignificant compared to predator disturbance, but illegal shooting of large numbers of adult gulls has major impacts in smaller sub-populations. Damming and excessive water abstraction reduces island habitat due to lowering of flows. Major climatic events such as droughts, and chemical ingestion through a diet dominated by agricultural invertebrates, are potential major threats about which little is known. Management actions including the collation and analysis of all unpublished black-billed gull count datasets, a thorough test of the accuracy of aerial monitoring, trialling of decoys to attract colonies to nest on islands, predator control at bank colonies, targeted weed control on high quality sites, advocacy and education and further research are recommended.

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Stoner, Lee, Anna G. Matheson, Lane G. Perry, Michelle A. Williams, Alexandra McManus, Maureen Holdaway, Lyn Dimer, Jennie R. Joe i Andrew Maiorana. "Principles and strategies for improving the prevention of cardio-metabolic diseases in indigenous populations: An international Delphi study". ACADEMIC PRESS INC ELSEVIER SCIENCE, 2017. http://hdl.handle.net/10150/625942.

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The disparity in life expectancy between Indigenous and non-Indigenous populations, including within high-income countries, is driven by a heightened risk of cardio-metabolic diseases. The current study recruited independent panels of experts in Indigenous cardio-metabolic health from Australia, New Zealand and the United States, in order to establish local consensus opinion and initiate dialogue on appropriate prevention strategies. Therefore, a three-round Delphi process was used to consolidate and compare the opinions of 60 experts, 20 from each country. Round one, the experts were asked twelve open-ended questions across six domains: (i) prevention; (ii) consultation; (iii) educational resources; (iv) societal issues; (v) workforce issues; (vi) culture and family. Round two, the experts completed a structured questionnaire based on results from the first round, in which they ranked items according to their importance. Final round, the experts were asked to re-rank the same items after receiving summary feedback about the rank ordering from the previous round. Several themes emerged common to all three countries: (i) socio-economic and education inequalities should be addressed; (ii) educational, behaviour change and prevention strategies should address physical environmental determinants and be responsive to the local context, including being culturally appropriate; and (iii) cultural appropriateness can be achieved through consultation with Indigenous communities, cultural competency training, use of Indigenous health workers, and use of appropriate role models. These findings highlight several key priorities that can be used to initiate dialogue on appropriate prevention strategies. Such strategies should be contextualized to the local Indigenous populations.

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Middleton, Danielle Mary Rose Lea. "The prevalence of Salmonella and the spatial distribution of its serovars amongst New Zealand's native lizards : a thesis presented in partial fulfillment of the requirements for the degree of Master of Science in Zoology at Massey University, Palmerston North, New Zealand". Massey University, 2008. http://hdl.handle.net/10179/906.

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This thesis considers the prevalence and spatial distribution of Salmonella serovars amongst wild endemic lizards on offshore islands around the coast of New Zealand. The mean test prevalence of faecal excretion of Salmonella was 4.7%. Skinks (Scincidae) were more likely (8.5%) to be carriers of Salmonella than geckos (1.6%). Each island was host to between one and three Salmonella serovars that were not found on any other islands in this study. Two exceptions were Salmonella Bousso and Salmonella Mana which were found on two islands within the same geographical area. Based on the findings of this study, different islands are likely to be hosts to different Salmonella serovars which could have implications for future translocations of native lizards. I also assessed the prevalence and spatial distribution of faecal excretion of Salmonella, Aeromonas and Hafnia alvei within Mana Island. The prevalence of Salmonella on Mana Island was estimated at 5.8%. Salmonella was found predominantly in skinks (10.0%) and less often in geckos (4.1%). H. alvei was found at a prevalence of 1.9%. No Aeromonas species were cultured from any of the cloacal swabs, suggesting that the 95% confidence interval for the true prevalence is 0-3%. Each site sampled in this study was host to one or more unique serovar of Salmonella not found at any of the other sites. The results of this study indicate that Salmonella serovars may become established within populations of lizards and is not spread between them. This may be due to a lack of dispersal of lizards between sites, raising important considerations for the translocation of native lizards. I investigated the prevalence of faecal excretion of Salmonella, H. alvei and Aeromonas by New Zealand native lizards from two captive populations. The mean prevalence of faecal excretion of Salmonella in the captive lizards sampled was 11.5%. There was a higher prevalence of Salmonella within captive population A (22.0%) than in population B (3.6%). No Aeromonas was cultured from any of the lizards. H. alvei was found at a prevalence of 5.2%. The prevalence of Salmonella and H. alvei was significantly higher in captive lizards than in wild populations. Captive lizards may, therefore, not be appropriate founders for new populations of wild lizards. Finally I assessed the different efficiencies of two media and two temperatures in isolating six Salmonella serovars from a reptilian source. All serovars grew equally well at 37°C and 27°C. For most serovars XLD agar was the more successful media than MacConkey agar but the success of different culture media depended on the serovar being cultured. Because lizards are frequently host to a wide range of Salmonella serovars, screening samples using multiple microbiological methods is likely to give the best chance of isolating all Salmonella serovars present.

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Quinn, Carolyn J., i n/a. "Stable isotopes and diet : indications of the marine and terrestrial component in the diets of prehistoric populations from New Zealand and the Pacific". University of Otago. Department of Anthropology, 1990. http://adt.otago.ac.nz./public/adt-NZDU20070601.115004.

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The importance of marine versus terrestrial foods in prehistoric Pacific and New Zealand diets, and the adaptation of the Polynesian diet to new enviroments, is examined through the analysis of the ratios in human bone of the stable isotopes of carbon, nitrogen and sulphur. In particular, this study seeks to obtain quantitative information which could provide answers to five main questions, relating to the subsistence focus of the early Lapita colonists in the Pacific, the significance of suger cane in the diets of early Pacific populations, the proportions of reef versus open ocean and terrestrial versus marine foods in these diets, and the identification of populations with pronounced marine or pronounced terrestrial diets. One hundred and nineteen samples of human bone from 13 sites throughtout the Pacific and New Zealand were processed. Nitrogen values were obtained directly from bone powder, while carbon values were determined from collagen produced by digesting bone powder in phosphoric acid. Sulphur evaluations were determined from a BaSo⁴ precipitate, produced after combustion of the collagen samples in a Parr bomb. Interpretation of results is approached from a comparative point of view, which enables the proportions of marine and terrestrial foods in the diets of each study group to be assessed in relation to the diets of all the other groups. Additional information on the composition of the diets is gained by comparing the stable isotope values obtained in this study with published values of other human populations, and of marine and terrrestrial plants and animals. The potential of stable isotope analysis to identify the composition of prehistoric New Zealand and Pacific diets is confirmed. A unique marine adaptation is revealed from the analysis of the Chatham Islands Moriori who appear to have focused almost exclusively on marine resources. In contrast, a highly terrestrial diet is suggested for groups from Nebira in Papua New Guinea and Lake Rotoiti in New Zealand.

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