A Calgary Zoo director arriving at work Thursday was stunned to find seven dead penguins in their pool.
The birds had drowned, according to necropsies, possibly exhausting themselves in some kind of panic, a veterinary team has speculated. The exact cause won’t be known for certain until an investigation is completed.
“This is devastating news,” animal care director Jamie Dorgan said in a statement. “We have launched a full investigation so we can try to understand what happened and prevent further incidents like this from happening again.”
It’s the second animal tragedy at the popular zoo this year. In February, an otter drowned when he became entangled in a pair of pants that workers had placed in his enclosure to play with.
In 2013, at least two penguins died of a bacterial infection at the zoo.
Since 2007, a hippo, 40 rays, a woodland caribou calf, a wild goat, a capybara, dozens of fish and a corn snake have died of unnatural causes at the zoo, the Calgary Herald noted.
The latest dead birds, all Humboldt penguins, ranged in age from 8 months to 7 years and represented a third of the Humboldt colony at the zoo. Dorgan told the Calgary Sun that he hoped the incident involved “strange one-off” behavior that wouldn’t claim any more lives.
The drownings occurred overnight while the penguins were being held in a special enclosure with a pool while changes were being made in the animals’ regular habitat.
Panic can easily spread among the birds because penguins are a “very social species,” Dorgan said.
“If one or two birds were in a bit of panic, everyone could have just got in the mix and perhaps they were getting worked up in the pool. But, really, we’re speculating at this point. Anything’s possible. It seems some stressor led to these birds going into some kind of panic.”
A British veterinary surgeon who visited the zoo after the 2013 penguin deaths told the Calgary Herald that such panic deaths can also occur in the wild. “Unfortunately, fluke events occasionally happen in wild penguin colonies, only on a far larger scale,” said surgeon Romain Pizzi. He said he knows the zoo staff to be “highly skilled” and “compassionate.”
But an expert at the University of Alberta told the Canadian Broadcasting Corp. that penguin drownings are extremely rare and usually occur if they become entangled in something, are dragged or are deliberately drowned by a predator.
Employees are checking video surveillance footage and will continue to examine the bodies for any clues. Watchdog group Zoocheck Canada is calling for surveillance cameras in all animal enclosures following the puzzling deaths.