Two staff members at a Canadian zoo who had given a pair of trousers to an otter have been disciplined after the animal drowned.
An autopsy revealed that Logan, the North American river otter, died after becoming entangled in the clothing item in the pool at Calgary Zoo, in the province of Alberta, earlier this month.
Although a keeper jumped into the pool, the 12-year-old otter could not be saved. Three otters now remain at the zoo.
An investigation into the death found that an “[unauthorised] enrichment item” was given to the otters by a zookeeper and that protocols had been broken by two staff members. They have now been disciplined.
Colleen Baird, the general curator at Calgary Zoo, said such an error was "simply unacceptable".
The zoo's animal care protocols were among the most stringent in the industry, she said, adding: “We will be reinforcing our protocols with every member of our Animal Care staff to prevent an incident like this from ever happening again.”
The Toronto Star reported that Ms Baird said animals were sometimes given enrichment items to encourage them to behave as they would in the wild. However, the trousers were not an item authorised to be given to the otters.
The incident was criticised by Julie Woodyer of animal welfare group Zoocheck. She told CBC: "It smacks of the kinds of things you might see at a roadside zoo, not in a professional operation."
There have been other incidents of deaths in unusual circumstances at the zoo before. In 2009 an employee was suspended when a capybara died after being crushed by a hydraulic door.