Avian Demography Unit
Department of Statistical Sciences
University of Cape Town
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African Black Oystercatcher, Haematopus moquini
by Kathy Calf

African Black Oystercatcher adults on Robben Island
Oystercatchers (Haematopus sp.) are shorebirds that inhabit most continental sea coasts. There are thirteen species of Oystercatcher worldwide and nine of these species occur in the Southern Hemisphere. The Northern Hemisphere species have been recorded to fly great distances between breeding and non-breeding areas whereas the African Black Oystercatcher is largely resident, migrating only short distances to nursary areas in Namibia after fledging and then returning to their natal sites to breed.

African Black Oystercatcher adult

The African Black Oystercatcher is the largest of all the species. Adults have jet black plumage, pinkish legs and a long, dagger-like orange-red bill. In addition its eye and eye ring are red. There is sexual dimorphism, females being larger and heavier with longer bills; a male weighing an average of about 660g and a female about 720g when fully grown.

African Black Oystercatcher chicks

African Black Oystercatchers can be found on both rocky and sandy shores throughout the year and they attempt to breed in varied habitat types. They are territorial throughout the year, however, during the non-breeding period they have been observed to form aggregations or roost in clubs. This is thought to function in predator avoidance as clubs are usually situated on offshore rocks or promonitories with good all-round visibility. These clubs tend to contain more birds at night when predation risk is greater. Unfortunately the Oystercatcher breeding season coincides with summer and summer holiday periods when use of the coast is at its peak. As a result in many areas birds are unable to breed successfully due to disturbance and increased predation risk as a result of disturbance. In high-disturbance areas there are declining numbers of Oystercatchers as these birds are unable to replace themselves. Chicks are speckled grey and brown with black bills but on fledging, at about three-quarter adult weight, their feathers resemble those of the adults and their bills have started turning orange. The immatures are easily distinguishable from the adults for up to six months after fledging but thereafter it becomes more difficult.

African Black Oystercatcher chick
African Black Oystercatcher chicks
African Black Oystercatcher chicks

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Last Modified 3 March 2003