• Login
    View Item 
    •   Home
    • Massey Documents by Type
    • Theses and Dissertations
    • View Item
    •   Home
    • Massey Documents by Type
    • Theses and Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Population genetics, biogeography and ecological interactions of the New Zealand bellbird (Anthornis melanura) and their avian malaria parasites : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy (Ph.D.) in Zoology at Massey University, Albany, New Zealand

    Icon
    View/Open Full Text
    02_whole.pdf (3.406Mb)
    01_front.pdf (752.9Kb)
    Export to EndNote
    Abstract
    Habitat loss and redistribution of species has lead to population declines and loss of genetic diversity with serious implications to species survival on ecological and evolutionary scales. While there is no doubt that rapidly dwindling endangered populations require our immediate attention, studies on common species are equally important. The purpose of this thesis is to investigate the genetic connectivity, biogeographical relationships and host-parasite interactions of a common and widely distributed bird species, mainly because we want common species to remain common. Furthermore, I illustrate how studies such as this provide invaluable comparisons for sympatric endangered species. In this thesis, patterns of genetic variation of the New Zealand bellbird (Anthornis melanura) are delineated to assess their re-colonization potential among fragmented landscapes. Using a phylogeographic perspective I show how dispersal ability and secondary contact among isolated population fragments shape the evolutionary trajectory of a species. I also determine the biogeographical relationships between the bellbird host and its malaria parasites with key emphasis on host-parasite specificity. Finally, immunological trade-offs are investigated in disease epidemiology by examining host factors that influence malaria prevalence. I show that an immense capacity for dispersal has prevented divergence and shaped the high levels of genetic diversity and connectivity in bellbirds today. However, substantial genetic differentiation among subpopulations reflects recent habitat fragmentation. Based on these findings I conclude that continued habitat loss can lead to further reductions in gene flow, despite dispersal. Though restricted to northern populations, I provide evidence that the most abundant avian malaria lineage infecting bellbirds is likely an endemic Plasmodium (Novyella). This parasite exhibits bimodal seasonality and male-biased infections, but these relationships vary among subpopulations. Malaria prevalence appears to be governed by food availability and territory stability, thus habitat disturbance has repercussions to immune phenotype. With this thesis I advocate a re-thinking of conservation strategies toward spatial planning that enables ‘natural’ secondary contact among habitat fragments. Translocation is not necessary for all species. In addition to being the first study on seasonal and host factors affecting malaria patterns in the Southern Hemisphere, this thesis makes major contributions to science by elucidating some ecological relationships that underpin the evolution of immunity.
    Date
    2011
    Author
    Baillie, Shauna Maureen
    Rights
    The Author
    Publisher
    Massey University
    URI
    http://hdl.handle.net/10179/2863
    Collections
    • Theses and Dissertations
    Metadata
    Show full item record

    Copyright © Massey University
    Contact Us | Send Feedback | Copyright Take Down Request | Massey University Privacy Statement
    DSpace software copyright © Duraspace
    v5.7-2020.1
     

     

    Tweets by @Massey_Research
    Information PagesContent PolicyDepositing content to MROCopyright and Access InformationDeposit LicenseDeposit License SummaryTheses FAQFile FormatsDoctoral Thesis Deposit

    Browse

    All of MROCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    Statistics

    View Usage Statistics

    Copyright © Massey University
    Contact Us | Send Feedback | Copyright Take Down Request | Massey University Privacy Statement
    DSpace software copyright © Duraspace
    v5.7-2020.1