African penguin
And it wasn’t something that happened millennia ago – it happened in this century. The “fault” is the lack of sardines; or the lack of sardines.
Thousands of African penguins (Spheniscus drowned) that live off the coast of South Africa will probably have died en masse from starvation during the moulting season, due to the collapse of their food sourcesconcludes a new study that analyzed two of the most important breeding colonies of the species.
I.e, starved to death.
According to the researchers, on Dassen Island and Robben Island — two historically central breeding sites for the African penguin — about 95% of the birds that bred in 2004 will have died within the next eight yearsin a period marked by persistent prey shortage.
Between 2004 and 2011, the population of sardine on the South African west coast remained consistently below 25% of its peak abundance, which would have caused a serious lack of food and an estimated decline of around 62,000 breeding individuals, co-author Richard Sherley of the Center for Ecology and Conservation at the University of Exeter.
The results come at a critical time for the species: in 2024, the African penguin was classified as “critically endangered”. For Sherley, the recovery of sardine biomass in key feeding areas “appears to be essential” for long-term survival.
Vulnerability becomes extreme during the annual molt. To to replace all feathers — a process that lasts approximately 21 dias — these birds they have to remain on land, without the ability to hunt.
Before they start molting, they need to accumulate fat reserves and then quickly recover their body condition.
I know food for hard to find before or immediately after molting, They may not have enough energy to survive the fast.
The authors relate the crisis to environmental changes and with the fishing. Changes in temperature and salinity will have reduced spawning success in traditional west coast areas and increased spawning to the south.
However, due to the historical structure of the sector, much of the fishing remained west of Cape Agulhas, increasing pressure on a stock already in decline.
The study states that the sardine exploitation rates reached 80% in 2006, which may have intensified penguin mortality.
The team analyzed counts of breeding pairs and molting adults between 1995 and 2015, integrating survival estimates obtained by capture-mark-recapture and comparing them with a regional index of prey availability.
A survival of adults — especially during molting — was strongly associated with the abundance of sardines and anchovies.
The drops observed in Dassen and Robben “are mirrored elsewhere” and are part of a global decline of almost 80% in 30 years, according to the authors.
Among the measures under debate are rules that reduce the exploitation of sardines when the stock is below 25% of the maximum and initiatives to reduce juvenile mortality.
On the ground, actions such as the installation of artificial nests, predator control and bird rehabilitation are taking place, in addition to a recent ban on purse-seine fishing around the country’s six largest breeding colonies, to improve access to prey at critical stages of the life cycle.
