Massey Documents by Type

Permanent URI for this communityhttps://mro.massey.ac.nz/handle/10179/294

Browse

Has files: YesSubject: search.filters.subject.Migration

Search Results

Now showing 1 - 6 of 6
  • Thumbnail Image
    Item
    Spatial consumption risk sharing
    (Elsevier B V, 2025-11-01) Arora P; Choo D; Hu C
    This paper investigates how bilateral economic linkages influence consumption synchronization across economies in response to idiosyncratic shocks. Using the US state-level data, we find the degree of bilateral consumption smoothing to decrease with geographic distance. To explain this fact, we develop an open economy DSGE model that incorporates trade, migration, and finance as channels of risk sharing subject to bilateral frictions that potentially covary with distance. Calibrated to the US data, this structural model enables us to examine interactions of different channels in general equilibrium and quantify their impacts on states’ consumption. Through counterfactual exercises, we find that turning off the three channels weakens consumption correlations across states in general, while trade is more effective than migration and financial channels in stabilizing consumption fluctuations.
  • Thumbnail Image
    Item
    Restoring connectivity for migratory native fish : investigating the efficacy of Fish Friendly Gates : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Zoology at Massey University, Palmerston North, New Zealand
    (Massey University, 2015) Bocker, Erin
    Stream connectivity and habitat diversity are key components of healthy river ecosystems. Human modification of natural flow regimes disrupts natural connectivity, and results in physical, chemical, and biological changes that impair natural river function. Such changes can be detrimental to freshwater species, particularly those which have evolved to be reliant on a variety of different habitats throughout their life cycles. Consequently, restoring connectivity has become a major restoration goal in freshwater ecology. Tide gates, a man-made coastal structure designed to protect low-land infrastructure from flooding, can negatively impact freshwater ecosystems. Through disrupting connectivity, tide gates impede the movement of aquatic biota and degrade upstream habitats. It is thought that the vast majority of tide gates in New Zealand and worldwide could be modified to enhance connectivity and fauna passage through the installation of Fish Friendly Gates (FFG's). This study is the first to investigate these claims. FFG's increased both the duration and distance that tide gates were held open over a tide cycle. These operational changes reintroduced some tidal fluctuation to upstream habitats but water levels remained within safe levels for infrastructure. FFG influence enabled upstream passage for giant bully and adult inanga, for which tide gates were otherwise impassable. Furthermore, upstream passage of whitebait (migratory galaxiid juveniles) and common bully were significantly increased when aided by FFG's. Although rapid and sustained increases in migratory species richness of resident populations were observed following FFG installation, due to small sample sizes these changes could not be regarded as statistically significant. Additionally, evidence of rehabilitation of degraded sites was limited and suggests care should be taken when restoring connectivity to poor quality habitat. Overall, this study demonstrated that FFG's can enhance upstream fish passage at tide gates while maintaining adequate flood protection. Whether FFG's can provide ecological benefits to degraded habitats requires supplementary research. Provided the limitations of FFG's are recognised and they are only installed where tide gate removal is not feasible, FFG's are an effective tool for facilitating fish passage through tide gates in New Zealand and worldwide.
  • Thumbnail Image
    Item
    The Northward migration stopover ecology of Bar-tailed Godwits and Great Knots in the Yalu Jiang Estuary, National Nature Reserve, China : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Ecology, Massey University, Palmerston North, New Zealand
    (Massey University, 2015) Choi, Chi-Yeung
    Stopover ecology is the scientific study of the behaviour of migrants, the interrelationships among migrants, and between migrants and their environment, at stopping sites. Many shorebird species are long-distance migrants and require high quality stopping sites to rest and refuel during migration. The suitability of a stopping site depends mostly on food availability, level of competition, and predation or disturbance pressure. Events at stopover may not only affect migration performance, but also the subsequent reproduction or survival, and therefore become the limiting factor for the population sizes of migrants. The stopping sites in the Yellow Sea along the East Asian-Australasian Flyway are used extensively by long-distance migratory shorebirds along the flyway, but very little is known about the stopover ecology of these birds. Moreover, the stopping sites within the Yellow Sea region are under serious threats; some of them are being lost before their importance to shorebirds is fully understood. In this thesis, my aim was to study the stopover ecology of Bar-tailed Godwits Limosa lapponica and Great Knots Calidris tenuirostris at an important stopping site in the northern Yellow Sea, the Yalu Jiang coastal wetland, during northward migration between 2010 and 2012. I estimated the number of these shorebirds transiting and their passage dates using repeated counts incorporated with Thompson’s modelling approach. I described the type, abundance and characteristics of their benthos resources by benthos sampling. I investigated their dietary compositions, foraging patterns and mechanisms of coexistence by behaviour scans, focal bird observations and faecal dropping analysis. Finally, I studied their predation impact on their main bivalve prey, Potamocorbula laevis, using exclosures. My results indicated that at least 42% of the East Asian-Australasian Flyway’s northward migrating L. l. baueri godwits, 19% of L. l. menzbieri godwits, and 22% of the Great Knots used Yalu Jiang coastal wetland, thereby indicating the importance of the study area to these species. Polychaetes and bivalves numerically dominated the benthic communities, while one bivalve species, P. laevis, constituted more than three quarters of total macrobenthic biomass during the study period. Great Knots, Red Knots Calidris canutus and Far Eastern Oystercatchers Haematopus ostralegus osculans selected mostly the bivalve P. laevis while Bar-tailed Godwits had a broader diet and selected mostly polychaetes, even though most of their intake was of P. laevis. Moreover, the size of P. laevis preferred by godwits and Great Knots overlapped. Their coexistence seems to be enabled by high resource availability rather than niche separation. The different dietary selections between godwits and knots possibly led to different foraging patterns on the tidal flats. There was clear behavioural evidence that a digestive bottleneck existed in the bivalve-feeding shorebirds. Such digestive constraints of hard-shelled prey, decreased prey quality (amount of energy per dry mass of shell taken), and increased handling and searching time were potential reasons behind a decline in total biomass intake rate in godwits and Great Knots from 2011 to 2012, despite similar numerical and biomass density of their main prey in both years. Finally, there was evidence that predation by shorebirds had a significant impact on the number of P. laevis in one of the years studied. My thesis showed the importance of Yalu Jiang coastal wetland to Bar-tailed Godwits and Great Knots during northward migration. These two species competed for the same bivalve prey and their coexistence in the years of study was enhanced by ample food resources rather than niche differentiation. The lack of young P. laevis recruitment in the final year of study and the significant predation impact detected indicated a potential decline in food resources after my study. Long-term monitoring will reveal how these species respond to the changes in prey availability. My study provided important scientific information on the numbers of birds using Yalu Jiang coastal wetland, their prey resource availability, their dietary compositions, and behaviours that are crucial for their conservation management in the reserve and potentially in other stopping sites in the Yellow Sea.
  • Thumbnail Image
    Item
    An application of satellite tracking technologies to conserve wildlife : a case study approach : a dissertation presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Natural Resource Management at Massey University, Palmerston North, New Zealand
    (Massey University, 2010) Thomas, Bindi; Thomas, Bindi
    Wildlife management is an important area of conservation and has become a priority for many countries and organisations around the world. One of the fundamental components of a sound wildlife management plan is a good understanding of a species’ behaviour and habitat. For animals within inaccessible environments, satellite tracking provides a powerful tool for revealing information on animal movements and their habitat requirements. In this dissertation, the conservation benefits and technical effectiveness of satellite tracking are examined through four case studies representing a diverse range of threatened species studied for periods between six months and five years. The studies revealed important ecological insights on the in situ movement and behaviour of the African elephant (Loxodonta africana), Kruger National Park, South Africa; the New Zealand bush falcon (Falco novaeseelandiae), Central North Island, New Zealand; the estuarine crocodile (Crocodylus porosus), Darwin, Australia; and the northern royal albatross (Diomedea sanfordi), Taiaroa Head, New Zealand and Chile. For each of these studies, satellite telemetry provided location data enabling analyses of the animals’ movements and home ranges, and these analyses inform specific management recommendations. For example, the long time series study on African elephants highlighted the importance of developing reciprocal animal management policies where cross-boundary movements of animals occurred between adjacent parks. The strengths and weaknesses of different satellite tracking systems are compared and guidelines developed to assist wildlife managers in selecting the best technology to suit their research needs. An assessment of the trade-offs between the technical features built into transmitters and the associated cost is also presented. The study shows how the use of satellite tracking systems provides conservation agencies with a better understanding of wildlife behaviour and strengthens their ability to improve wildlife management planning.
  • Thumbnail Image
    Item
    Careers in cross-cultural context : a study of Sri Lankan immigrants in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Management at Massey University, Albany, New Zealand
    (Massey University, 2005) Tharmaseelan, Nithiyaluxmy
    This study considered migrants’ career outcomes as the result of their adjustments in terms of culture and career adaptation along with other positive attributes they brought on their arrival as well as developing in their new country. It considered that career is the property of individuals and managing it successfully is the responsibility of individuals themselves. Prior research into migrants’ issues and careers was used as the basis of this study and a model for analysis was developed using such issues. The resultant model included the wider life of migrants. A questionnaire including reliable measures of key variables was developed based on the literature. Two hundred and twenty-one Sri Lankan migrants completed the pilot tested survey. The results were analysed using factor analysis, tests of association and multiple regression analysis at the first stage to formulate a less complex model. Structural equation modelling was then used to confirm the relationships assumed between different variables. Although some of the relationships and/or variables assumed initially were removed from the model, the final model explained strong links between the variables that remained. Qualification gained before migration and career self-efficacy were found to be the most significant variables in explaining job satisfaction before migration. Usefulness of prior knowledge, skills and habits, efforts made towards career, education in New Zealand, information seeking, length of time in New Zealand and overseas experience had the greatest influence on current job level. Current job level, length of time in New Zealand and overseas experience were found to be the most significant variables explaining subjective career success after migration. Adapting to New Zealand culture was found to be significant in explaining only the career satisfaction after migration. It was also found that migrants’ career outcomes (success and satisfaction) after migration were significant variables in explaining overall career satisfaction of this migrant group: however, with the exception of job satisfaction, career outcomes before migration did not play a significant role in determining overall career satisfaction. The implications of the present study were considered, from both migrants’ perspective and that of New Zealand as the host society. A number of possible practical strategies relevant to migrants, community organisations and policy makers and authorities were suggested. Several potential avenues for future researches were identified and discussed. Thus, it is expected that this study will contribute to better career outcomes of migrants in New Zealand.
  • Thumbnail Image
    Item
    Rethinking Polynesian mobility: A new Polynesian Triangle?
    (2009-07-16T23:38:08Z) Barcham, Manuhuia; Scheyvens, Regina; Overton, John
    No abstract available