While the drowning remains a mystery, Schubert believes captivity played a role in the penguins' deaths. "Living in the wild would always be preferable to living in captivity, because as hard as we humans might try, we cannot emulate their natural habitat in captivity," he said. "There's no way that the polar plunge exhibit provides them with the space or the psychological enrichment that they would normally receive in the wild, and therefore, those animals were in a compromised position."
The Calgary Zoo did not immediately respond to The Dodo's request for comment.
If you want to help penguins - and other animals in captivity - visit Zoocheck to learn about things you can do.