Avian cholera is killing thousands of our seabirds
Western Cape Nature Conservation
Thousands of Cape Cormorants, and hundreds of Cape Gannets have recently been
affected and killed by pasteurellisis or avian cholera. This is a bacterial
disease which strikes stressed birds. The last major southern African outbreak
was ten years ago at Dassen Island. Over the past few weeks reports of deaths
have come from Dassen Island (near Yzerfontein), Saldanha Bay, and Bird Island
at Lambert's Bay. The indication is that these birds are being stressed by a
widespread food shortage although there may be other factors.
Dr Tony Williams, marine bird specialist at Cape Nature Conservation, says
that "disease is natural and serves as a form of selection by removing
weaker individuals in a population. Many birds will receive mild doses and
develop immunity to further outbreaks."
Conservation agencies can do little to prevent the spread of this disease.
However, they will, where feasible, collect and remove carcasses for burial.
This is being done in order to minimise the chance that, as hot weather returns,
the carcasses do not become breeding grounds for Botulinus clostridium which can
cause outbreaks of botulism and kill additional birds.
Avian cholera affects a few birds every year, but this year the numbers
affected are unusually high. Also, normally only cormorants are affected, but at
present gannets are also dying from the disease.
More Information:
Amanda van Niekerk
Tel: (021) 483 4728
Fax: (021) 483 3500
Cell: 082 550 6546
email: amvnieke@pawc.wcape.gov.za
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