Calgary Zoo found ‘no definitive evidence’ as to what caused 7 penguins to drown

The Calgary Zoo says although they have completed their investigation into the death of seven Humboldt penguins last month, they still haven’t found out what caused the birds to die.

In a Thursday news release, Jamie Dorgan, director of animal care, said the zoo had conducted “detailed interviews” with everyone “relevant to the situation” and also consulted with penguin behaviour experts outside the facility.

“We could find no definitive evidence as to what caused this incident.”

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The penguins were found dead in one of two pools in the back holding area of the Penguin Plunge exhibit at around 7:15 a.m. on Thursday, Dec. 8, 2016.

READ MORE: Petition urges Calgary Zoo to shut down penguin enclosure after 7 birds die

Officials said the 22 birds were in the back area as construction work was taking place in the building. Necropsies determined they died as a result of drowning.

“Penguins normally roost quietly throughout the night,” Dorgan said. “It appears that something, perhaps unusual behaviour within the colony, frightened the penguins during the night which caused them to suddenly jump into one of the two pools in the holding area; unfortunately seven were unable to get out safely.”

“It was extraordinary and tragic.”

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The zoo said despite the lack of conclusive evidence, it will make a number of precautionary changes to how penguins are kept in the back holding area to avoid a similar situation from happening again, including:

• Restricting access to pools in back holding areas when staff are not present and the number of birds are over a specific threshold (this change was implemented immediately following the penguin deaths).
• Setting a maximum capacity for the number of birds that can be held in the holding areas.
• Investigating making physical changes to the holding pools.
• Ensuring continuous ambient lighting at night in the back holding areas.

According to the Calgary Zoo, the remaining 15 Humboldt penguins are in “good health” and remain in Penguin Plunge alongside three other penguin species — kings, gentoos and rockhopper penguins.