 |
|
Oystercatchers 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 nursery areas in Namibia after fledging and then returning to
their natal sites to breed.
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
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 promontories 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 them.
 |
|
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 juveniles are
easily distinguishable from the adults for up to six months after
fledging but thereafter it becomes more difficult. |
|
 |
|
