The population dynamics and conservation of the African Black Oystercatcher, Haematopus moquini
| Autor: | Loewenthal, Douglas |
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| Jazyk: | angličtina |
| Rok vydání: | 2007 |
| Předmět: | |
| Druh dokumentu: | Doctoral Thesis |
| Popis: | Includes bibliographical references. The African Black Oystercatcher is currently classified as Near-threatened by virtue of the fact that the population size is small «10 000) and numbers have decreased or were previously recorded as decreasing. Aspects considered to be of conservation concern to the species are (a) its inherently low and variable breeding success; (b) its ground-nesting habit, making it vulnerable to numerous direct and indirect impacts of human disturbance; (c) its susceptibility to mass mortalities, particularly of adult birds in high-density breeding populations. Inherent factors which may of benefit to the species' persistence are its considerable longevity and, potentially, a degree of connectivity between local populations, although current evidence suggests that this is very low. However, in addition to these considerations, over the past 25+ years the variety and intensity of potential threats and benefits to the species have also changed and this may have changed the species' conservation status. While human activity has increased in many areas of the species' breeding range, African Black Oystercatcher populations may be benefiting from and increase in the number of Marine Protected Areas as well as an improved food supply in the form of an invasive alien mussel species, Mytilus galloprovincialis. In light of the key factors outlined above and the territorial nature of the species, all of which are considered to be of importance to the species' population dynamics and conservation, the main aims of this study were to: (a) reassess the global population and, where changes have occurred, to provide an explanation for these changes; (b) assess the importance of, and manner in which human disturbance may impact breeding populations; (c) assess levels of natal site philopatry and adult site fidelity in local populations; (d) assess the long-term population viability of the species; and (e) assess the potential importance of territorial behaviour in governing the population dynamics of local oystercatcher populations. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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