Penguins in peril
Over the last 8 years, numbers of African Penguins have fallen by half, resulting in the species being listed as Endangered on the IUCN’s Red List. The FitzPatrick Institute, in partnership with BirdLife South Africa and the Department of Environment Affairs is studying the cause of their collapse.
African penguins have a long history of human exploitation. Once people could reach the offshore islands where penguins breed, the birds and their eggs were collected for food. Penguins went extinct on Robben Island shortly after the Dutch colonized the Cape, and by the early 20th century more than 250,000 eggs were collected each year from other colonies – roughly half of all the eggs the penguins laid! Guano scraping caused additional disturbance and further reduced breeding success.
We don’t know how many African Penguins there were before humans began impacting on their populations. At the beginning of the last century Dassen Island alone still supported about one million penguins. By 1956 there were fewer than 75 000 pairs on Dassen, and the total population was less than 150 000 pairs. Despite a ban on egg collecting and the cessation of guano scraping penguin numbers continued to fall. Oil pollution was partly to blame, with many birds being oiled following the closure of the Suez Canal in 1967, and the resultant increase in shipping around the Cape.
But a shortage of food posed perhaps the greatest threat. By the late 1970s, fewer than 70,000 pairs survived. Namibia suffered the most severe decrease, falling to less than one quarter of its 1956 population following the collapse of sardine stocks as a result of overfishing. Even in South Africa, where an increase in anchovies partly offset the reduction in sardines as a food source, penguin numbers still decreased. In the late 1990s a series of exceptionally good years of fish recruitment along the west coast of South Africa saw the penguin population in the Western Cape recover somewhat; breeding numbers more than doubled by 2004. Since then, however, their numbers have plummeted, reaching an all time low of barely 25,000 pairs.
The reason for their recent collapse remains subject of ongoing debate, but there’s no disputing that African Penguins are in trouble. Resightings of ringed adults at Dassen and Robben islands suggest that adult mortality increased from around 20 per cent per year in 2002–04 to more than 40 per cent by 2006. Again a shortage of food seems to be the root cause of the problem, although predation and increasingly extreme climatic events are also contributing to low survival and poor breeding success. Urgent action is needed if we are to ensure the survival of African Penguins in the wild.