The avian influenza A(H5N8) virus, which has claimed numerous victims among the African Penguin colony on Halifax Island near Lüderitzbucht since the beginning of this year, seems to be under control. According to penguin expert Dr Jessica Kemper, no dead penguins have been found on Halifax and the other islands off Namibia’s coast since early May. Earlier this year, 397 carcasses were discovered and burned on Halifax Island (10 ha) alone, another 45 on Ichaboe Island (6 ha) and 19 on Mercury Island (3 ha). Countless dead penguins were spotted in the Atlantic Ocean. It is believed that at least 600 of the endangered flightless birds have died of the dreaded disease.

Bird Flu
Halifax Island is situated in Guano Bay near the lighthouse of Lüderitzbucht and Diaz Cross. It is approximately 10 hectares in size and a breeding area for African Penguins, also called Jackass Penguins. The population was stable in recent years but has been drastically reduced by the avian influenza A(H5N8) virus since the beginning of this year.

But the losses are probably even bigger, says Dr Kemper. Almost all of the perished penguins were adult birds with a permanent partner. If they had a clutch or chicks at the time of their death, the young will not have survived either because a single parent is not able to brood and/or raise chicks alone. For the survivors which had not started breeding yet it will be a lost year if the partner was killed by the flu. It is a serious setback for Namibia’s penguin population.

According to Dr Kemper only 22 000 breeding pairs of African Penguins, also called Jackass Penguins, are left worldwide. Some 5 800 of them live in Namibia. Their numbers have been dropping for years because overfishing has caused a shortage of anchovies and sardines, normally the staple diet of African Penguins. Instead they now have to eat less nutritious fish. Added to that, there is a lack of nesting sites ever since guano deposits on the islands were depleted in previous centuries. Penguins used to dig their nests into the metre-deep layers of guano. Disruptions and oil pollution also had a negative effect on the African Penguins.

Bird Flu
Overexploitation of guano more than a hundred years ago destroyed countless breeding caves of penguins. Chicks now have to be raised exposed to the elements. This leaves them vulnerable to attacks by enemies like the Kelp Gull.

Experts are relieved that the dreaded virus has not spread to other critically endangered species. Cape Gannets are classified as endangered in Namibia: only 13 000 pairs are left off the coast of Namibia and they now breed on six islands only, three of them in Namibia and three in South Africa. The number of Bank Cormorants has dwindled to 2 500 pairs worldwide – 2 000 of which breed on Mercury Island.

In future Namibian government authorities need to respond and intervene faster at the first signs of the disease. This time a catastrophe was averted thanks to the efforts of mainly private individuals. If the virus is not controlled it not only threatens seabirds but also chicken farms and other poultry. The disease can be spread by various types of birds such as gulls, pigeons, ducks and ravens. According to scientists, the virus is transmitted by aquatic birds in particular.

Author: Dirk Heinrich


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