Four mule deer, similar to these in Colorado, died at the Calgary Zoo in 2009 mostly because of what investigators described as 'poor handling facilities.' ((Nathan Bilow/Associated Press))

There have been several unpublicized cases of animals at the Calgary Zoo being injured or killed inadvertently because of unqualified staff members or poorly designed exhibits, according to a report by external auditors.

Compiled by the Canadian Association of Zoos and Aquariums and the U.S. Association of Zoos and Aquariums, the report was released by the zoo on Thursday, along with a 36-point action plan to address the findings.

In the past few years, many animals have died at the Calgary Zoo — including a baby elephant, a hippo, a wild goat, four gorillas and 41 stingrays — generating intense media attention.

When a capybara was crushed to death by a hydraulic door in 2009, the zoo invited outside experts to conduct a review of its practices.

The audit uncovered several more incidents where zookeeper error or exhibit design flaws caused animal deaths, according to the lengthy final report, which notes:

  • A spider monkey was fatally crushed by a hydraulic door.
  • Another spider monkey died from frostbite complications after it was left outside in cold weather.
  • Four feather-tailed sugar gliders — mouse-like mammals — were either crushed to death underfoot or by a door.
  • Several mule deer were killed or injured while handlers tried to capture them for veterinary checks.
  • Dozens of Sebas and Pallas bats died after hitting piano wire strung across their cages as part of their exhibit. 
  • Woodland caribou and muskox were repeatedly injured or killed either because of exhibit design or interspecies aggression. African wild dogs were also injured for the same reasons.

"The number of deaths due to human error is significantly higher than at other similar institutions," the report said.

Zoo implementing action plan

As part of its action plan, the Calgary Zoo said it is taking steps to address all of the findings in the report.

Both species of bats are being removed from the zoo, as are the feather-tailed gliders. Four of the six African wild dogs have gone to another zoo and the rest will be relocated soon, officials said.

The zoo is also implementing a twice-yearly review of mortality among the animal collection and a third clinical veterinarian was hired in March to help with the workload.

In January, zoo officials denied an allegation by Zoocheck Canada that the mule deer had died because of human error.


Stingrays at the Calgary Zoo began dying mysteriously in 2008 because of what turned out to be an improperly oxygenated tank. ((CBC))

However, Thursday's report concluded that even in cases where the animal deaths were due to flaws in the exhibit, as was the case with the mule deer, "these deaths appear to reflect a poor institutional response to a clearly identified problem."

The deaths of caribou and muskoxen could also have been prevented if the zoo had taken action when it became clear the two species were not mixing well, the report said.

The zoo now has a plan to improve how cases of interspecies aggression are handled, officials said.

Investigators also commented on the deaths of more than 40 cownose stingrays in 2008 when their tank wasn't properly oxygenated.

"Knowledgeable husbandry staff did not have input into the design of the life-support systems for this exhibit," they said.

In response to the report's suggestion that insufficient staff training led to some animal deaths, the zoo said it will implement a retraining program and "where necessary, external hiring to obtain required skills not available internally."

With files from the CBC's Erin Lawrence