• Login
    View Item 
    •   ResearchSpace Home
    • College of Agriculture, Engineering and Science
    • School of Life Sciences
    • Biological Sciences
    • Zoology
    • Doctoral Degrees (Zoology)
    • View Item
    •   ResearchSpace Home
    • College of Agriculture, Engineering and Science
    • School of Life Sciences
    • Biological Sciences
    • Zoology
    • Doctoral Degrees (Zoology)
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Aspects of the biology of the red bishop Euplectes orix and other Euplectes species.

    Thumbnail
    View/Open
    Thesis. (16.38Mb)
    Date
    1977
    Author
    Craig, Adrian John Fergus Knott.
    Metadata
    Show full item record
    Abstract
    The breeding biology and the annual cycle of the Red Bishop Euplectes orix was studied over a two year period in Natal. Some comparative data were also gathered for the related species the Red-shouldered Widow E. axillaris and the Red-collared Widow E. ardens, and additional data from a ringer in Rhodesia have been analysed. The breeding season of these polygynous ploceids coincides with the summer rainy season, and the amount of breeding activity in the Red Bishop appeared to be correlated with the amount of rain during the previous year. Breeding success at the colony studied was low; predation was the major cause of nest failure. In all three species the entire population, including the juveniles, undergoes a complete moult at the end of the breeding season. There is some evidence that the birds may make local movements during the winter dry season. These species are sexually dimorphic, the males being larger than the females. The population sex ratio was Significantly biased in favour of males in the Red Bishop and the Red-shouldered Widow but not in the Red-collared Widow. However, about half the male birds are subadults which do not breed, so that there is an excess of females in the breeding population. Adult males undergo a partial moult at the start of the breeding season and acquire a distinctive nuptial plumage. This is shed again at the post-nuptial moult, and in eclipse plumage they resemble the females. There is a similar pattern of weight change in all three species, with peaks early in the breeding season and again during the moult. The lowest annual weights are recorded during the dry season. The mortality rate of the Red Bishop is not high for a small passerine. The findings of this study are compared with the available information on other members of the genus, and discussed in relation to the evolution of polygyny in the Euplectes species.
    URI
    http://hdl.handle.net/10413/11257
    Collections
    • Doctoral Degrees (Zoology) [92]

    DSpace software copyright © 2002-2013  Duraspace
    Contact Us | Send Feedback
    Theme by 
    @mire NV
     

     

    Browse

    All of ResearchSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsAdvisorsTypeThis CollectionBy Issue DateAuthorsTitlesSubjectsAdvisorsType

    My Account

    LoginRegister

    DSpace software copyright © 2002-2013  Duraspace
    Contact Us | Send Feedback
    Theme by 
    @mire NV