Project Oystercatcher

The African Black Oystercatcher (Haematopus moquini) is one of the most conspicuous birds of the Western Cape.  Few people know, however, that this iconic bird species was classified as Near Threatened in the International Red Data Book in 2000, because of its restricted range and limited population.  In the early 1980's there were still only about 4800 of them left – the majority on the Islands on the West coast of South Africa (75%) and Namibia (25%).

There are several reasons for their low numbers: African Black Oystercatchers first start breeding when they are older than three or four years and also have only one clutch per year.  Although they lay 2-5 eggs, the annual breeding success is only 0.6 young/pair in protected sites and 0.3 in unprotected sites.  The first-year survival rate is also very low - at 20%. A survey of breeding success carried out in March 1997 yielded alarming results – along some parts of the west coast the number of chicks reared was barely one tenth of that needed to maintain a healthy population. 

African Black Oystercatchers live mainly on filter feeders such as bivalves and limpets and is therefore highly susceptible to harmful algal blooms (“red tides”) which can cause severe local mortality – up to 30-50%.  Avian cholera is also a huge threat.

The African Black Oystercatchers live on both rocky and sandy coasts and to a lesser extent, in estuaries and lagoons.  About 53% of the world’s population can be found on the 1000 kilometre coast between the Olifants River and Mossel Bay.  Of these about 30% are on the offshore islands, mostly in and around Saldanha Bay. Between the Orange River and the Olifants River, oystercatchers are believed to be quite scarce. 

Because Oystercatchers` lives are confined to the coast, they are potentially at risk from all sorts of human factors, ranging from pollution and coastal development, to straightforward disturbance by man, his pets and his toys.  One of the reasons why 4x4s were prohibited to drive on the beaches in 1994, was precisely the plight in which the Oystercatchers were found, and despite the huge public outcry the African Black Oystercatchers' breeding success significantly increased within one year.

An unforeseen fortuitous factor was the introduction of the alien Mediterranean Mussel (Mytilus galloprovincialis) after which island oystercatcher populations increased by 83-156%.  This highly invasive species has taken over our coast at an alarming rate of 115km per year. Since this alien species started to supplant our indigenous mussel, the African Black Oystercatcher adjusted its diet and started feeding on the abundant Mediterranean Mussels.  These alien mussels are also bigger and therefore offer more energy.  It has been reported that the oystercatcher`s reproductive potential has increased following these aliens` establishment.  Good news for our oystercatchers.

Ongoing conservation and monitoring efforts, and the proclamation of marine reserves, have also been of great benefit to this iconic species.  Although the Oystercatchers` numbers have grown to about 6700 birds today, it is still restricted in range and numbers, and potentially vulnerable.

The Oystercatcher Conservation Programme is a multi-organisational project spearheaded by the Percy FitzPatrick institute of African Ornithology at the University of Cape Town.  The aim is to develop a conservation strategy for the oystercatcher and to raise awareness of the conservational needs of Southern Africa`s coast.  Its success, to a large extent, is dependent on public support and participation.

This is why the awareness of the real state of emergency in which this endemic bird species find itself, is so important to us at Footsteps and from the start it was one of Jacobus' chief objects during his eco-walk.  

With the help of Carl Swart, Chairman of A Rocha SA, we came into contact with Dr Mark Brown of the Nature's Valley Trust.  He is very excited about the prospects of working with us and especially to receive important data about the range or distribution and numbers of oystercatchers in the unknown diamond areas north of the Olifants River.  

In the past week Mark Anderson, CEO of Birdlife SA, contacted us and pledged their full support.  To make this oystercatcher-project part of our Footsteps-awareness even more special, is the fact that the African Black Oystercatcher is South Africa's bird of 2018.