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    Functional significance of highly variable colouration in the shore skink (Oligosoma smithi) : a thesis presented in partial fulfilment of the requirements for the degree of Doctor in Philosophy in Ecology at Massey University, Albany, New Zealand
    (Massey University, 2017) Baling, Marleen
    Variation in animal colouration is attributed to several biological functions, a key one being camouflage. Background-matching is a camouflage strategy where prey conceal themselves from predators by resembling their immediate backgrounds. Achieving optimal background-matching can be challenging, particularly in 1) visual backgrounds that form a mosaic caused by spatial variations in habitat characteristics, and 2) varying predator abundance or behaviour. Additionally, crypsis can be affected by alternative and potentially antagonistic functions, such as intraspecific signalling and thermoregulation. This thesis aimed to investigate the selective processes that affect prey colouration for background-matching in a heterogeneous environment. Specifically, I focused on the influence of habitat gradients, predator behaviour, and the potential conflict between camouflage requirements and thermoregulation or intraspecific signalling. Firstly, I conducted a detailed survey on the colour and colour patterns of a wild shore skink population (Oligosoma smithi) within a continuous heterogeneous habitat at Tāwharanui Regional Park. This population’s body colouration showed a significant association with a vegetation gradient, consistent with selection for background-matching. However, field experiments also revealed that predation risk for the more common colour pattern variants was double that of the rarer variant’s regardless of background type, consistent with predictions for apostatic selection (negative frequency-dependent selection). Secondly, I demonstrated that population colouration can respond to a change of habitat. One year after a translocation of shore skinks to an island habitat with a disjunct two-patch background, the population’s colours matched the simple substrate type (bare rocky stones) more than the complex substrate (high vegetation cover on sand). Skinks were darker, less intense in colour, and had lower colour pattern diversity compared to the founder and source populations at Tāwharanui. This study highlighted the potential significance of considering camouflage requirements of a species in human-induced translocations. Thirdly, in an analysis of seasonal effects to camouflage, I found no evidence that background-matching in the Tāwharanui population was compromised by differences in body colours between breeding and non-breeding seasons. This is likely because colours associated with intraspecific signalling (i.e. that exhibited age-dependence and sexual dichromatism) were located in the ventral body regions of skinks that would typically be hidden from predators. Finally, across 17 populations, shore skink colouration showed patterns of spatial variation consistent with thermal melanism (thermoregulation) and island syndrome. Despite the strong correlation of maximum monthly temperature on colours and latitude on colour patterns, I suggest that the significantly darker island populations were caused by a combination of local adaptation (i.e. crypsis) and non-selective forces (e.g., genetic drift). Overall, my thesis provides new insight on how different selection processes maintain dramatic colouration within a species, and marks the first quantitative research on colouration in New Zealand reptiles.
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    Colour variation of red kiwifruit and environmental factors affecting its colour expression : a thesis presented in partial fulfilment of the requirements for the degree of Master of AgriScience in Horticulture at Massey University, Palmerston North, New Zealand
    (Massey University, 2015) Henwood, Roxanne
    Development of a red kiwifruit cultivar with good size, storage ability, and colour is desirable as the genetic potential exists and it could expand the market for kiwifruit. However, red kiwifruit cultivars, including the subject of this thesis, frequently have inconsistent colour. This thesis aimed to quantify colour variation of this red cultivar and the levels at which this occurred, as well as examining environmental factors (chiefly temperature and light) that may influence colour variation. To achieve this, two harvests were collected in March to May 2014 from eight trial blocks located in five regions around New Zealand (Far North, Western Bay of Plenty, Eastern Bay of Plenty, Gisborne, and Nelson). Orchard information was collected, including within orchard temperature variation via X-Sense temperature loggers, and fruit was assessed for maturity attributes and colour using subjective and objective tests. It was found that the greatest colour variation was at the orchard and region level, though variation between vines and positions within a vine was also significant. Region was not the largest influence on colour, as out of the three regions with two orchards, two of them had both high and low colour orchards. Colour was significantly predicted by fruit firmness, estimated light exposure, numbers of leaf layers, and skin colour in a linear mixed effects model. Lower firmness related to higher colour, as did paler, less exposed fruit with a higher number of leaf layers. The effects of light and leafiness may have been mediated by temperature, as carbohydrate supply seemed to be a less important factor for colour. Temperature was not formally identified as a significant factor; however, a relationship between flesh colour and temperature was implied by light exposure data and by scatterplots. These relationships may have implications for canopy management of this variety. Further investigation of the relationship between light exposure, fruit temperature, and colour may be helpful for determining appropriate management practices for this variety. Additionally, further work on temperature may provide a basis for predicting the colour expected in a given season.
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    Making moves : an adventure through space, colour & form : an exegesis presented with exhibition as fulfilment of the requirements for thesis Masters of Fine Arts at Massey University, Wellington, New Zealand
    (Massey University, 2012) Peters, Gary C G
    This exegesis reveals a practice that has been driven by making as the means to address questions concerning colour, space, form, time and site. From an initial desire to create a sustainable and self generating painting practice this text plots the development of a systematic method that uses data derived from choose-your-own-adventure books. As the system is deployed across a variety of sites, wall drawing and paper folding become the focus where the rules based generation of form is fused with an intuitive sense of placement and use of colour. Further deployment explores the role of colour in response to site, the temporal nature of this work and it’s engagement with the viewer resulting in a response to architectural site.
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    A calculation of colours: towards the automatic creation of graphical user interface colour schemes : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Computer Science at Massey University, Palmerston North, New Zealand
    (Massey University, 2010) Moretti, Giovanni S.
    Interface colour scheme design is complex, but important. Most software allows users to choose the colours of single items individually and out of context, but does not acknowledge colour schemes or aid in their design. Creating colour schemes by picking individual colours can be time-consuming, error-prone, and frustrating, and the results are often mediocre, especially for those without colour design skills. Further, as colour harmony arises from the interactions between all of the coloured elements, anticipating the overall eff ect of changing the colour of any single element can be difficult. This research explores the feasibility of extending artistic colour harmony models to include factors pertinent to user interface design. An extended colour harmony model is proposed and used as the basis for an objective function that can algorithmically assess the colour relationships in an interface colour scheme. Its assessments have been found to agree well with human evaluations and have been used as part of a process to automatically create harmonious and usable interface colour schemes. A three stage process for the design of interface colour schemes is described. In the fi rst stage, the designer speci es, in broad terms and without requiring colour design expertise, colouring constraints such as grouping and distinguishability that are needed to ensure that the colouring of interface elements reflects their semantics. The second stage is an optimisation process that chooses colour relationships to satisfy the competing requirements of harmonious colour usage, any designer-specified constraints, and readability. It produces sets of coordinates that constitute abstract colour schemes: they de fine only relationships between coloured items, not real colours. In the third and fi nal stage, a user interactively maps an abstract scheme to one or more real colour schemes. The colours can be fi ne-tuned as a set (but not altered individually), to allow for such "soft" factors as personal, contextual and cultural considerations, while preserving the integrity of the design embodied in the abstract scheme. The colours in the displayed interface are updated continuously, so users can interactively explore a large number of colour schemes, all of which have readable text, distinguishable controls, and conform to the principles of colour harmony. Experimental trials using a proof-of-concept implementation called the Colour Harmoniser have been used to evaluate a method of holistic colour adjustment and the resulting colour schemes. The results indicate that the holistic controls are easy to understand and eff ective, and that the automatically produced colour schemes, prior to fi ne-tuning, are comparable in quality to many manually created schemes, and after fi ne-tuning, are generally better. By designing schemes that incorporate colouring constraints specifi ed by the user prior to scheme creation, and enabling the user to interactively fi ne-tune the schemes after creation, there is no need to specify or incorporate the subtle and not well understood factors that determine whether any particular set of colours is "suitable". Instead, the approach used produces broadly harmonious schemes, and defers to the developer in the choice of the fi nal colours.