Assessment of the conservation status of African Black Oystercatcher Haematopus moquini
97 – 108
26 August 14
Les G. Underhill
Animal Demography Unit, Department of Biological Sciences, University of Cape Town, Rondebosch, 7701 South Africa
The African Black Oystercatcher Haematopus moquini occurs in southern Africa, breeding exclusively in Namibia and South Africa. The non-breeding range extends into Angola and Mozambique. The population size in the early 2000s is estimated to be 6,670 birds, an increase of 46% since the early 1980s, and continues to increase. The breeding range is expanding eastwards, into KwaZulu-Natal. The increase in population size is attributed to the invasion of the southern African shoreline by the Mediterranean Mussel Mytilus galloprovincialis, better conservation management of the offshore islands and a ban on off-road vehicles driving on beaches in South Africa. Females are larger than males, with the largest relative distance being in bill length with the bills of females being 13% longer than those of males. Breeding takes place during the austral summer, mainly October to March, but stretching into May. Mean clutch size is 1.8 eggs, with most clutches having one or two eggs; there has been an increasing proportion of three-egg clutches. Human disturbance and coastal development, both impacting oystercatchers both during the breeding season and outside of it, are regarded as key threats to the species. Because the African Black Oystercatcher breeds in the open, in the narrow zone between the spring high-tide level and the edge of the coastal vegetation, two predicted consequences of climate change are likely to impact breeding success: higher temperatures may result in embryos overheating; storm surge events, especially if they coincide with spring high tide, are likely to result in losses of eggs. Nine postgraduate research projects have focused on the African Black Oystercatcher since 2000, generating a vast of amount of new knowledge and insights into the species. We recommend that the current conservation status for the African Black Oystercatcher, as ‘Near-threatened’ can no longer be justified, and that the species be reclassified as ‘Least concern’.