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Auckland, New Zealand

Igic B.,University of Auckland | Leuschner N.,University of Auckland | Parker K.A.,Massey University | Ismar S.M.H.,University of Auckland | And 5 more authors.
Journal of Morphology | Year: 2010

Sex differences in behavior, morphology, and physiology are common in animals. In many bird species, differences in the feather colors of the sexes are apparent when judged by human observers and using physical measures of plumage reflectance, cryptic (to human) plumage dichromatism has also been detected in several additional avian lineages. However, it remains to be confirmed in almost all species whether sexual dichromatism is perceivable by individuals of the studied species. This latter step is essential because it allows the evaluation of alternative hypotheses regarding the signaling and communication functions of plumage variation. We applied perceptual modeling of the avian visual system for the first time to an endemic New Zealand bird to provide evidence of subtle but consistent sexual dichromatism in the whitehead, Mohoua albicilla. Molecular sexing techniques were also used in this species to confirm the extent of the sexual size dimorphism in plumage and body mass. Despite the small sample sizes, we now validate previous reports based on human perception that in male whiteheads head and chest feathers are physically brighter than in females. We further suggest that the extent of sexual plumage dichromatism is pronounced and can be perceived by these birds. In contrast, although sexual dimorphism was also detectable in the mass among the DNA-sexed individuals, it was found to be less extensive than previously thought. Sexual size dimorphism and intraspecifically perceivable plumage dichromatism represent reliable traits that differ between female and male whiteheads. These traits, in turn, may contribute to honest communication displays within the complex social recognition systems of communally breeding whitehead and other group-breeding taxa. © 2010 Wiley-Liss, Inc. Source


Sharma S.,Auckland Regional Council | Gutierrez J.A.,University of Auckland
Electronic Markets | Year: 2010

This paper presents a study of the characteristics of viable business models in the field of Mobile Commerce (m-commerce). Mobility has given new dimensions to the way commerce works. All over the world various stakeholder organisations are consistently probing into the areas where m-commerce can be exploited and can generate revenue or value for them, even though some of those implementations are making the business environment more complex and uncertain. This paper proposes a viable business model evaluation framework, based on the VISOR model, which helps in determining the sustainability capabilities of a business model. Four individual cases were conducted with diverse organisations in the Information Technology sector. The four cases discussed dealt with mobile business models and the primary data was collected via semi structured interviews, supplemented by an extensive range of secondary data. A cross-case comparative data analysis was used to review the patterns of different viable business components across the four cases and, finally, the findings and conclusions of the study are presented. © 2010 Institute of Information Management, University of St. Gallen. Source


Kennedy D.M.,Victoria University of Wellington | Paulik R.,Auckland Regional Council | Dickson M.E.,University of Auckland
Earth Surface Processes and Landforms | Year: 2011

One of the longest standing debates in rocky coast geomorphology is whether subaerial weathering or wave processes dominate shore platform evolution. The origins of this debate date to the mid-nineteenth century when the first descriptions of Old Hat Islands were provided from northern New Zealand. Old Hat Islands are surrounded by a broad near-horizontal shore platform. Their formation was inferred to relate to subaerial weathering of bedrock to a level of permanent saturation with wave processes acting only to remove the weathered debris. To date, no detailed topographic surveys have been conducted on the Old Hat Islands in New Zealand that initiated this debate; in this study we provide the first quantitative data on the original field sites. Topographical surveying and Schmidt Hammer hardness testing were conducted on >25 profiles of varying wave exposure. In contrast to the classic descriptions, platform elevation varies from just above mean high water spring (MHWS) at the most exposed sites, to mean high water neap (MHWN) at the most protected sites or mean sea level (MSL) where beaches occur on the platform surface. There is no significant difference between the hardness of the cliffs and the platforms fronting them and no clear relationship between wave exposure and platform width. Rather than being exclusively dominated by subaerial process, the formation of microtidal, sheltered, Old Hat Island platforms is considered to be a function of (i) the rate of weathering, (ii) exposure to wave energy, (iii) nearshore water depth and (iv) rock resistance. Shore platform elevation in the study area is thought to be a function of the level at which waves erode cliff rock, and the action of weathering which lowers platform surfaces. The width of platforms is strongly influenced by the ability of waves to dissect the platform edge along vertical joint lines. © 2010 John Wiley & Sons, Ltd. Source


Collier K.J.,University of Waikato | Surrey G.M.,Auckland Regional Council | McArthur K.,Horizons Regional Council | Nicholson C.,Horizons Regional Council | And 2 more authors.
New Zealand Journal of Marine and Freshwater Research | Year: 2010

The New Zealand fish fauna contains species that are affected not only by river system connectivity, but also by catchment and local-scale changes in landcover, water quality and habitat quality. Consequently, native fish have potential as multi-scale bioindicators of human pressure on stream ecosystems, yet no standardised, repeatable and scientifically defensible methods currently exist for effectively quantifying their abundance or diversity in New Zealand stream reaches. Here we report on the testing of a back-pack electrofishing method, modified from that used by the United States Environmental Protection Agency, on a wide variety of wadeable stream reaches throughout New Zealand. Seventy-three first- to third-order stream reaches were fished with a single pass over 150-345m length. Time taken to sample a reach using single-pass electrofishing ranged from 1-8 h. Species accumulation curves indicated that, irrespective of location, continuous sampling of 150 stream metres is required to accurately describe reach-scale fish species richness using this approach. Additional species detection beyond 150m was rare (<10%) with a single additional species detected at only two out of the 17 reaches sampled beyond this distance. Apositive relationship was also evident between species detection and area fished, although stream length rather than area appeared to be the better predictor. The method tested provides a standardised and repeatable approach for regional and/or national reporting on the state of New Zealand's freshwater fish communities and trends in richness and abundance over time. Source


Davis M.D.,Auckland Regional Council | Jayaratne R.,Auckland Regional Council | Ansen J.-A.,Auckland Regional Council | Timperley M.,Timperley Consultants
World Environmental and Water Resources Congress 2010: Challenges of Change - Proceedings of the World Environmental and Water Resources Congress 2010 | Year: 2010

This paper describes characterisation of urban sediment and stormwater quality derived from a range of field studies undertaken over the last 10-years in the Auckland region, New Zealand. The most comprehensive field work involved monitoring of eight sub-catchments in the Auckland City in 2000-1. The monitoring included three single land-use control sub-catchments: (1) commercial, (2) industrial and (3) residential, while the remaining five sub-catchments were of mixed land use. Other sampling involved monitoring runoff components within sub-catchments: roads and motorways; carparks and industrial sites Urban sediment and stormwater quality yields by land use, material (principally roof runoff) and activity level (principally traffic volume) were derived. Stormwater contaminants characterised included three heavy metals of concern in the Auckland region: zinc, copper and lead; and polycyclic aromatic hydrocarbons. Nutrients (total nitrogen and total phosphorus) and enterococci were characterised from the sub-catchment monitoring. Particle size distributions (PSD) were generated from available data and distilled into 'typical' PSDs for (1) urban streams, (2) urban pipe networks and (3) construction (earth work) sites. Auckland regional yields generally are similar to United States and Australia studies. Zinc yields generally are high owing to runoff from a large quantum of older, galvanized roof material yet lower than some northern hemisphere studies. The PSDs of sediment in the Auckland region lie between the United States (which has a larger fraction of larger sized particles) and Australia (which has a larger fraction of smaller sized particles). © 2010 ASCE. Source

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