Articles by Author: Gm Rishworth

Search results for Gm Rishworth

We found 6 results for you
  1. Lumbering the gauntlet: Cape Gannet fledglings killed by African Penguins

    Lumbering the gauntlet: Cape Gannet fledglings killed by African Penguins

    Item type: Journal Article • Journal: Ostrich: Journal of African Ornithology
    This account presents the first known observations of Cape Gannet Morus capensis fledgling mortalities as a result of aggressive nest defence behaviour by African Penguins Spheniscus demersus. Observations were conducted in 2013 on Bird Island, Algoa Bay, South Africa –...
  2. The nursery role of a sheltered surf-zone in warm-temperate southern Africa

    The nursery role of a sheltered surf-zone in warm-temperate southern Africa

    Item type: Journal Article • Journal: African Zoology
    Marine fish nurseries such as surf-zones have usually been classified as nurseries based solely on the density of pre-adult fish, yet the full suite of developmental stages are seldom assessed because of difficulties associated with sampling these habitats. The larval...
  3. Fish utilization of surf-zones. Are they changing? A case study of the Sheltered, warm-temperate King’s Beach

    Fish utilization of surf-zones. Are they changing? A case study of the Sheltered, warm-temperate King’s Beach

    Item type: Journal Article • Journal: African Zoology
    Surf-zone fish communities and their shifts over time are generally poorly understood. The aim of this study was to compare the current surf-zone fish assemblage at King's Beach, South Africa, to a similar study conducted three decades ago, before the...
  4. Sex differentiation based on the gular stripe in the apparently monomorphic Cape gannet

    Sex differentiation based on the gular stripe in the apparently monomorphic Cape gannet

    Item type: Journal Article • Journal: African Zoology
    The Cape gannet, Morus capensis, has long been considered a monomorphic species despite attempts at phenotypically separating the sexes. In a further effort we here recorded morphometric measurements from genetically sexed Cape gannets. Discriminant function analysis was used to classify...
  5. Population fluctuations of <em>Cerithidea decollata</em> (Gastropoda: Potamididae) in mangrove habitats of the St Lucia Estuary, South Africa

    Population fluctuations of <em>Cerithidea decollata</em> (Gastropoda: Potamididae) in mangrove habitats of the St Lucia Estuary, South Africa

    Item type: Journal Article • Journal: African Journal of Marine Science
    Mangrove macrobenthos species are used as ecological indicators as they are sensitive to changes in sediment properties. In this study, the population density of the common mangrove whelk Cerithidea decollata was assessed during different environmental conditions in the St Lucia...
  6. Distribution and habitat use of Indo-Pacific bottlenose dolphins Tursiops aduncus along the south coast of South Africa

    Distribution and habitat use of Indo-Pacific bottlenose dolphins Tursiops aduncus along the south coast of South Africa

    Item type: Journal Article • Journal: African Journal of Marine Science
    The distribution and habitat use of the Indo-Pacific bottlenose dolphin Tursiops aduncus along the south coast of South Africa was investigated using bi-monthly boat-based surveys, from 2013 to 2016, over a distance of 145 km between the Goukamma and Tsitsikamma...