Scientific Services

Sixty-five endangered African penguins mysteriously died overnight at Boulders African Penguin colony. Excellent sleuthing skills combined with specialist attention to detail and knowledge found the unlikely cause to be death by bee stings. The incident highlights the value of collaborating with specialists and veterinarians.

At sunrise on Friday, 17 September 2021, a group of dead penguins was discovered on a routine patrol at Middle Beach of Boulders African Penguin colony. Staff from SANParks and the City of Cape Town immediately responded and found 65 dead penguins. All the dead birds were in a localised area, out in the open. Penguin Rangers checked around the colony and confirmed that the birds in the rest of the colony were fine. None of the dead penguins had any apparent physical injuries. The discovery of the dead penguins was a surprise because there was no previous signs of distress or illness.

Initially, we suspected the possibility of a fast-acting illness, pollution or a poisoning event. The dead penguins were taken to Southern African Foundation for the Conservation of Coastal Birds  (SANCCOB), where seabird specialists and vets began conducting post-mortems. Back at the colony, ongoing checks were made to identify possible causes of the incident and be on the lookout for any penguins in distress.

Late on Friday night, a vet from SANCCOB found several bee stings embedded around the eyes of one of the dead penguins. SANParks, City and SANCCOB staff returned the next day to look for dead bees at the scene because bees die when they sting. The team found hundreds of dead Cape honeybees (Apis mellifera capensis), providing more evidence that bees had stung the penguins multiple times. Simultaneously, another vet at SANCCOB confirmed that all the dead penguins had numerous bee stings, with up to 27 stings in one bird. The team concluded that the most likely cause of death was acute kidney failure from bee toxins.

Some clues to the cause of death for penguins found at Boulders African penguin colony; bee stings around the eyes of penguins , dead bees and a small bee colony inside one of the artificial penguin nests (Photos: David Gordon Roberts, Jenny Cullinan and Alison Kock).

On Saturday afternoon, we enlisted a bee expert’s help to determine whether a bee colony or beehive in the area had been disturbed. We knew that the rangers would have seen an obvious bee colony on their daily patrols. Therefore, we looked for a bee colony in dense bush or underground that the penguins might have disturbed. We found a small colony of fewer than 1500 bees inside one of the artificial nests near the site. This bee colony had not been there two days before during weekly nest checks. While we cannot confirm whether these bees were part of the swarm that stung the penguins or not, it is probable. The small colony of bees was moved to another part of the Park, far away from the penguin colony.

Although determining whether the bees came from a natural colony or a beehive is not possible, beekeeping has become popular in the Boulders vicinity. This incident provides an example of the potential risk of high levels of beekeeping in mixed-use landscapes and the need for awareness of unintended consequences of beekeeping.

Head of African penguin covered in bee stings (Photo: David Gordon Roberts).

The unusual event sparked national and international media attention with numerous stories in leading news outlets, including the New York Times and Washington Post and a feature on the local TV documentary programme, Carte Blanche.

This article was originally published in the 2021/2022 Research Report.