A swarm of bees has killed 63 endangered African penguins on a beach outside Cape Town.
The birds were found dead on Friday on the beach at Boulders, a popular tourist destination south of Cape Town.
They were part of a colony of African penguins (Spheniscus demersus) living in a nature reserve, which are considered endangered, according to the International Union for Conservation of Nature (IUCN) Red List.
The area is a national park and the Cape honey bees are part of the ecosystem.
“After tests, we found bee stings around the penguins’ eyes,” David Roberts, a clinical veterinarian and part of the Southern African Foundation for the Conservation of Coastal Birds, said on Sunday.
“This is a very rare occurrence. We do not expect it to happen often, it’s a fluke. There were also dead bees on the scene.”
The South African National Parks said the birds were taken to the foundation for post-mortem – which showed all the penguins had multiple bee stings – and samples sent for disease and toxicology testing.
“There were no external physical injuries found on any of the birds,” a parks statement said.
Some of the animals were found with 20 or more bee stings, spokeswoman for the South African Nature Conservation Authority SANParks Lauren Howard-Clayton, told the dpa news agency on Monday.
Subsequent tests for toxins or pathogens were inconclusive.
Authorities are now searching for the hive to find out what may have triggered the bee attack, Howard-Clayton said.
The penguins, also known as Cape, black-footed or jackass penguins, breed in South Africa and neighbouring Namibia.
In the past three decades, the number of penguins living in South Africa has dropped by 73 percent to 10,400 pairs, according to the Foundation for the Conservation of Coastal Birds in Southern Africa.
In Namibia, there are still 4,300 penguin pairs.