Many South African penguins ‘starved to death’, study finds
It is believed the population drop is linked to the availability of sardines.
Populations of the African penguin in South Africa are estimated to have dropped significantly in just eight years as a result of food scarcity.
Researchers believe that 95 per cent of the penguins bred in 2004, from Dassen Island and Robben Island, died from starvation in the following eight years. It is suspected that they died en masse during their moulting season.
As part of a study, contributed to by the University of Exeter, the deaths have been linked to levels of sardine stock off west South Africa during this time. Between 2004 and 2011, the sardine stock was recorded as being below 25 per cent of its peak abundance.
It is estimated that this has resulted in the deaths of 62,000 breeding individuals during across eight years.
It is hoped that the study, which saw the University of Exeter partner with the South African Department of Forestry, Fisheries and the Environment, will inform management strategies to secure the long-term survival of the birds.
As of 2024, African penguins have been classified as Critically Endangered. It is now theorised that restoring sardine biomass could be essential for species survival.
The penguins’ annual moulting period leaves them at the most vulnerable. During this time, the birds are shedding and replacing their worn-out feathers to keep up insulation and water-proofing.
Without this protection, the birds must stay on land. They are unable to hunt during the moulting process, which takes about 21 days.
They are therefore evolved to build up fat, before fasting during their moult, followed by a feast to regain body condition afterwards.
This means that, if food is hard to find before or after they moult, they will have insufficient reserves to survive the fast.
The reductions in sardine stock has been linked to changes in the temperature and salinity of popular spawning areas. This has caused the penguins’ west coast area to be less successful, as the south coast becomes more successful.
However the reduced penguin population has become evident across the world, with the global population estimated to have declined by nearly 80 per cent in the past 30 years.
While the improvement of sardine availability is largely dependent on environmental factors, researchers believe there are steps that can be taken.
Richard Sherley, from the University of Exeter’s Centre for Ecology and Conservation, said: “Fisheries management approaches that reduce the exploitation of sardine when its biomass is less than 25% of its maximum and allow more adults to survive to spawn, as well as those that reduce the mortality of recruits [juvenile sardines], could also help, although this is debated by some parties.”
The full study can be found in the journal Ostrich: Journal of African Ornithology.
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