Dozens of endangered penguins in South Africa were killed last week by a swarm of bees.
More than 60 of the protected birds were found Friday on Boulders Beach, a tourist spot near Cape Town with multiple bee stings. The Southern African Foundation for the Conservation of Coastal Birds said in a statement that it suspected a nest of Cape honey bees was to blame.
Many dead bees were also found on the scene.
At first, investigators thought a predator had caused the deaths, but postmortems revealed bee stings around the eyes of the birds, Katta Ludynia, research manager at the foundation, told NBC.
It was the first known attack of its kind.
Alison Kock, a marine biologist with South Africa’s national parks agency, told BBC that usually the penguins and bees co-exist.
“The bees don’t sting unless provoked ― we are working on the assumption that a nest or hive in the area was disturbed and caused a mass of bees to flee the nest, swarm and became aggressive,” she said. “Unfortunately the bees encountered a group of penguins on their flight path.”
African penguins live on the coast and islands of South Africa and Namibia. Threatened by fishing, hunting, oil and gas drilling, mining and climate change, the small sea birds’ populations are rapidly declining.
This article originally appeared on HuffPost and has been updated.