The feeding behaviour of the European hedgehog (Erinaceus europaeus L.) has been investigated in a pastoral environment. Sampling methods that caused the minimum interference to the natural population were used. The relative importance of the various prey species in the diet were analysed by occurrence, relative volume and direct counting techniques. Problems often associated with the use of direct counting were successfully overcome. It was established that the main animal food items in the hedgehog diet were earwigs, lepidopteran larvae, beetles, harvestmen, dung flies, slugs, and earthworms. Small quantities of a large number of other species were also consumed. Several variations in the diet were found to be related to changes in the availability of food species. Although hedgehogs are capable of consuming large numbers of grass grub beetles (Costelytra zealandica) during the flight season it is concluded that they are unlikely to provide any effective measure of biological control of this pasture pest. Hedeghog diet was not influenced significantly by the sex of the animal, or by pasture irrigation. It was demonstrated that the feeding rhythm of captive animals, fed under laboratory conditions, was similar to that observed in the field. Observation showed that hedgehogs were active for an average of eight hours per night, with a period of maximum activity between 9 p.m. and 11 p.m. Animals tended to follow relatively fixed routes on successive nights. Excluding nestlings, the population density in an irrigated clover-ryegrass pasture was found to vary from four (winter) to eight (summer) animals per hectare. The average minimum feeding range of these animals was 2.4 hectares, although their feeding ranges overlapped considerably.

The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

The vegetation of the island of Rangitoto was examined in order to determine the current vegetation pattern and to identify the factors which have influenced the development of this pattern. Information about the order and dates of eruptive events was reviewed to gauge the length of time that the various surfaces of the island have been available as a substrate for the development of a vegetation covering. Available geological information, dating evidence, historical accounts, tree ages, and Maori evidence all point to a single period of eruptive activity, probably only several years in duration, around the mid- to late-1300's (A.D.). The order of eruption was probably production of the ash that covers neighbouring islands, followed by cinder cone building, followed by eruption of the lava flows. The lava flows were found to consist of clinkery aa flows, blocky aa flows, and a flow type referred to as Rangitoto slab flows. These flow types could be partially distinguished from one another, using discriminant analysis, on the basis of the length of the longest fragment on a 5x5m plot and the number of fragments on a lxlm subplot. A new transition sequence of flow types from pahoehoe to aa lavas is proposed for viscous lavas undergoing low rates of shear strain. The vegetation pattern of the lava fields was examine using TWINSPAN and CANOCO analysis of foliage cover percentage information gathered from 125 5x5m plots. It was found to consist of a successional sequence of vegetation arranged in a mosaic. The mosaic was found to relate strictly to the underlying lava flow surface. Large Metrosideros grow in crevices on slab flows and next to large boulders on aa flows. Smaller Metrosideros grow on small slabs on slab flows. Mixed species scrub is found growing on unbroken slab surfaces. The relative rate of colonisation of different types of flows under different climatic conditions was considered. The Metrosideros hybrid swarm was studied using morphometric information. The putative parent species of the swarm were found, using Principal Components Analysis, to be Metrosideros excelsa and Metrosideros robusta. The Rangitoto Metrosideros population was found, using Canonical Variates Analysis, to be the result of hybridisation, followed by introgression towards M. excelsa . The probable F1 hybrids grow in early successional stage vegetation. The major geographical trend is the tendency for backcrossed hybrids to grow on the eastern side of the island, suggesting eastern origins of M. robusta seeds. The impact of browsing animals on the vegetation was studied over five years in exclosures and corresponding control sites. Metrosideros foliage recovered slightly. Griselinia lucida and Cyathodes juniperina seedlings were recruited into the shrub layers in exclosures, but not in control sites. Astelia seedlings also benefitted from the absence of browsing pressure, as did Thelymitra longifolia. The distribution of browsing animal populations in relation to the vegetation pattern was studied using faecal pellet recruitment data gathered by the New Zealand Forest Service in 1984. Both wallabies (Petrogale penicillata penicillata) and possums (Trichosurus vulpecula) were found to be distributed principally according to the amount of palatable foliage available to each species in each vegetation type. / Appendices restricted at the request of the author

For 130 years dinosaurs have been divided into two distinct clades – Ornithischia and Saurischia. This dissertation looks at the earliest evolution of the clade Dinosauria by focusing upon the interrelationships of the major subsidiary clades within it. It does this following examination, comparison and description of early dinosaur material, and by utilising modern phylogenetic analysis techniques, to rigorously and objectively test the fundamental groupings within the clade Dinosauria using a newly compiled dataset of early dinosaurs and other dinosauromorphs (= close dinosaur relatives). The current consensus on how the principal clades within Dinosauria (Theropoda, Sauropodomorpha and Ornithischia) are related to one another is challenged by the results of these analyses. This study finds, for the first time, a sister-group relationship between Ornithischia and Theropoda, here termed Ornithoscelida. Consequently, a new definition for Dinosauria is presented, as the historic definition would exclude all members of Sauropodomorpha from the clade. As well as this, I propose revisions to the definitions of each of the principal dinosaurian sub-divisions and propose a new timeframe and geographic setting for the origin of Dinosauria. These new hypotheses force re-evaluations of early dinosaur cladogenesis and character evolution, suggest the independent acquisition of hypercarnivory in multiple dinosaur groups and offers an explanation for many of the anatomical features previously regarded as striking convergences between theropods and early ornithischians. As well as presenting new anatomical data on many early dinosaurs and dinosauromorphs, including a comprehensive re-description of the postcranial anatomy of Lesothosaurus diagnosticus (Chapter 2), and a new anatomical dataset of early dinosaurs (the largest ever compiled), this thesis goes on to implement the new dataset to investigate a number of important outstanding questions about early dinosaur evolution and provides new lines of enquiry for future workers to pursue. The results of this thesis reveal the oldest known members of the dinosaurian clades Theropoda and Sauropodomorpha (Chapter 6), as well as a new clade within Ornithischia; a taxon previously thought to represent a derived theropod has been recovered as a potential ‘missing link’ between theropods and ornithischians using the new dataset. This work now provides a unique tool for the assessment of the phylogenetic affinities of early dinosaurs and dinosauromorphs and, once published, will hopefully become the benchmark dataset for palaeontologists working in this area.

The response of yarrow (Achillea millefolium L.) seedlings to reduced light, interference from barley (Hordeum vulgare) and some aspects of regeneration from rhizomes were the subject of investigations from 1976 until 1980. Seedlings grown under four intensities of photosynthetically active radiation (100, 46.8, 23.7 and 6.4% of full summer daylight) were harvested on six occasions and the changes with time in the logarithms of leaf area, leaf, stem, root and total dry weights per plant were described by polynomial regression equations. Relative growth (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf weight ratio (LWR) were derived directly from the growth curves. SLA and LWR increased with increased shading causing LAR to rise, while NAR declined. Response curves of RGR on light intensity, derived from linear regressions of LAR and NAR on the logarithm of relative light intensity predicted maximum RGR to occur at light intensities which decreased with time. This was a consequence of ontogenetic changes in LAR, and changes in NAR apparently related to self shading. Linear regressions of LAR and NAR at a constant total plant dry weight of 1.62 g showed that the increase in LAR almost completely compensated for the reduction in NAR down to approximately 40% full daylight, and maximum RGR was predicted to occur at 59% full daylight. The light compensation point was estimated to be 3.6% full daylight. Yarrow populations established from 25 and 50 10 cm rhizome fragments m⁻² were grown alone and with barley at 194 or 359 plants m⁻². The barley populations were also grown alone. Growth analysis employing the regression technique showed the RGR of yarrow was reduced by barley from before jointing (Feekes Scale, Stage 6) as a consequence of reduced NAR. The NAR of yarrow was significantly reduced in the continued presence of barely, which by the time of the final barely harvest resulted in 91 and 94% reduction in the accumulated yarrow dry matter at 194 and 359 barely plants m⁻² respectively. The proportion of total dry matter allocated to seed and rhizome was also reduced by barley but the barley was unaffected by the yarrow. During the autumn and early winter, after removal of the barley, the suppressed yarrow had a higher RGR than the unsuppressed population, owing to higher LAR and NAR. Rhizome growth was vigorous during both autumn and winter in all yarrow populations, but the RGR of rhizome dry matter was higher in the suppressed yarrow during the autumn. This resulted in a progressive reduction in the difference in rhizome dry matter between suppressed and unsuppressed populations. Several aspects of the development and regenerative potential of rhizomes were investigated. In the first experiment, plants were established from seed and rhizome fragments and harvested on several occasions. Plants from both propagules formed rhizomes on which approximately 97% of auxiliary buds remained dormant, as long as the plants were undisturbed. Buds on rhizomes attached to the parent plant formed rhizome branches when the apex was damaged, had emerged from the soil, or in situations where internodes were congested. In the second experiment, rhizome fragments of 4, 8 and 16 cm in length were planted in soil at depths of 0, 2.5, 5.0, 10.0, 20.0 and 30.0 cm. All fragments on the soil surface died without forming shoots owing to desiccation whilst 100% mortality at 20 and 30 cm was probably the result of flooding. Within the 2.5 to 10.0 cm range, an increasing percentage of fragments survived (produced an aerial shoot(s)) as burial depth was reduced and fragment length increased. Within this depth range, the percentage of buds which had become active on undecayed fragments declined with increased length and burial depth. In the third experiment, single-node rhizome pieces were excised from rhizomes retrieved from field populations over a one year period, and incubated at 25°C for 10 days in darkness. More than 90% of buds formed vertical shoots throughout the year, indicating there was no period of innate dormancy in isolated buds. The effect of time of planting on the pattern of early regenerative development was assessed in the fourth experiment, in which 10 cm rhizome fragments were planted at 5 cm depth in soil on two occasions (in November and April). The developmental pattern was the same regardless of month of planting and new rhizomes were initiated at nodes on the vertical subterranean shoots when 5 to 6 aerial leaves had developed. The planted rhizome fragments declined in dry weight and a minimum weight occurred at about the time when rhizome initiation began.

The sap beetle genus Carpophilus Stephens (Coleoptera: Nitidulidae) is a large genus consisting of over 200 species and are found worldwide. Several species are important pests of crops and stored products, and are frequently intercepted as part of biosecurity operations. The genus is poorly known taxonomically, and there are several species groups that are challenging to identify by morphological methods. In particular, two species found across the Pacific, C. maculatus Murray and C. oculatus Murray are frequently confused with each other. These two species are similar in size and colour, but differ primarily by the shape of the colour pattern on their elytra. However, this colour pattern is highly variable within both species, leading to ambiguity in the indentification of these species. Within C. oculatus, three subspecies have been described based on differences in the male genitalia and pronotal punctation: C. o. oculatus and C. o. gilloglyi Dobson are distributed widely across the Pacific, while C. o. cheesmani Dobson is known only from Vanuatu. A search of literature records and specimen collections revealed 32 species of Carpophilus recorded from the Pacific region. In addition there remain several unidentified specimens representing at least four species, two of which will be described subsequent to this research. A number of species recorded in the literature may have been misidentified, and these require further field collections and inspection of museum specimens to confirm their presence in the Pacific. To test the validity of the subspecies of C. oculatus, and its distinctiveness from C. maculatus, a phylogeny of available specimens of Carpophilus was inferred from one mitochondrial gene (cytochrome c oxidase subunit I (COI)), and two nuclear genes (28S ribsomal RNA (28S) and the internal transcribed spacer 2 (ITS2)). These data show large genetic distances between the three subspecies of C. oculatus of 7-12%. Given these distances are similar to those between other species in the genus, this indicates these subspecies may be elevated to full species. The data also consistently support a monophyletic relationship between C. o. oculatus and C. o. gilloglyi. Nuclear genes also support C. o. cheesmani as part of a clade with the other subspecies, but these relationships are unresolved in COI. Carpophilus maculatus was not supported as being the sister taxon of the C. o. oculatus and C. o. gilloglyi clade. Other relationships within Carpophilus were unresolved, possibly due to a combination of incomplete taxon sampling, and saturation of substitutions within the COI gene. Phylogeographic analysis of specimens collected from several localities within the range of C. oculatus showed that, with only one exception, there were no shared haplotypes between archipelagoes. This result suggests it may be possible to determine the provenence of intercepted specimens, providing further information regarding potential invasion pathways. A degree of geographic structuring was also present within C. o. gilloglyi, being separated into a western clade found in Fiji and Rotuma and an eastern clade distributed from the Kermadec Islands and Tonga to French Polynesia. This separation was most profound in COI data, with a mean pairwise distance between the clades of 7%. ITS2 data also demonstrates a degree of differentiation between the two clades, based on differences in the insertions and deletions between the clades. The variability in the shape and colour of the elytral pattern of C. oculatus was also investigated. Colour was quantified using a method based on Red-Green-Blue (RGB) colour values derived from digital photographs, while an outline analysis of the elytral pattern was conducted using elliptic Fourier analysis (EFA). Principal Components Analysis of the RGB values and EFA coefficients showed no clear separation between subspecies, nor were any trends correlated with host fruit or collection localities. Variation at all levels and all measures studied in this thesis show that this geographic region and this genus of beetles offer intruiging insights into speciation, biogeography and biological invasions. There is much scope for further research on the causes and consequences of this variation and the lives of these interesting insects.