Officials at the Calgary Zoo say the death of a Gentoo penguin last December was a freak accident.

The female penguin, named Fiona, died after swallowing a stick that ended up in the open-air penguin exhibit.

"We're always on the look out for that kind of stuff. In this case, we don't know where the stick came from or what the reason was this bird took it in," said the zoo's general curator Jamie Dorgan.

Handlers noticed the female's behaviour was off and took her for an examination, where a veterinarian found she had swallowed a stick that was nearly a foot long.

Dorgan said the stick was surgically removed and she appeared to be recovering, but died eight days later from internal bleeding.

He says penguins are curious and may have thought the stick was nesting material.

"We've been incredibly lucky to get through a full year with 46 birds and this is the first death we had," said Dorgan.

"Penguins have an average life span of somewhere around 20 years; realistically, we should be over the years seeing an average of two penguins dying a year as we go along. Statistically that's the way it is."

He says staff do check the exhibit before letting out the birds and that day was no exception.

Death not out of the ordinary, say zoo officials

Zoo visitor Krista Boyce still has confidence in the zoo.

"It's sad to hear about a death of course, but considering the numbers they have here, I think it's positive in general. The exhibit is beautiful," said Boyce.

Zoo officials say they didn't release a media statement in December because they knew the circumstances of the death and there was no need for an investigation.

The zoo didn't put out a news release at the time because officials don't consider the death to be anything out of the ordinary.

"We don't put out a press release for every animal death. We are a large zoo, we have a lot of animals, all kinds of comings and goings, births, deaths [and] acquisitions," said Dorgan.

The Penguin Plunge has become one of the most popular exhibits at the Calgary Zoo since it opened last year.

The zoo has experienced several animal deaths in recent years including a hippo, wild goat, capybara and stingrays.

In December, two employees were disciplined after a great grey owl died.

It happened while the workers were transferring it from one holding area to another and the bird flew into a gate.

The zoo said an investigation showed the workers did not take reasonable precautions to ensure the owl's safety.

With files from The Canadian Press