Staff, volunteers, and patrons of the Assiniboine Park Zoo are mourning the loss of its 10-year-old fox.

"It’s with great sadness that we are announcing the passing of (our) beloved red fox, Simon," the Zoo said in an online announcement on Thursday.

"At ten years old, Simon was a senior gentleman, and has been loved dearly for many years here at the Zoo by his caregivers, as well as other staff, volunteers, Zoo members, and visitors."

a red fox plays in snowSimon was "gentle and loving" according to staff, and loved to play games with his caregivers. (Assiniboine Park & Zoon/Facebook)

The Zoo says that Simon had begun to exhibit "abnormal behaviour to his caregivers" earlier in the week. He was to undergo emergency surgery but died before the surgery took place. Officials say that the response was quick, but it was later discovered that Simon had "a large abdominal tumour, likely on his adrenal gland, which proved fatal."

Simon came to the Assiniboine Park Zoo in 2013 from Alberta. He was discovered there as an orphan, and he was too used to humans. The decision was made that the fox would therefore be unsuitable to be released back into the wild and came to call Winnipeg home as a result.

"Simon was very gentle and loving with his care team," the announcement says. "He enjoyed his positive reinforcement training sessions, and getting belly rubs and chin and ear scratches from the people he trusted most. We loved to hear his typical fox squeals when he was happy and excited!"

red fox in the snow with happy birthday signs behind him.Simon celebrated his 10th birthday earlier this year. (Assiniboine Park & Zoon/Facebook)

"One of Simon’s favourite games with his care team was for someone to bury their hand in the sand and move their fingers, which he would excitedly dig up! He was particularly fond of winter gloves and mitts, which he would steal from his care team and hide in his habitat. Some gloves were recovered after spring melt, but if you were lucky, he would dig them back up early as a surprise.

"Simon will be greatly missed. He was a wonderful ambassador for his species, as well as our local habitats and wildlife, for many years. Please help us in offering condolences to the members of our animal care team who worked with Simon every day."

Nature Canada says that Red foxes are found in all of Canada's provinces and territories, making them one of the most widespread mammals in the country. It also says that despite its name, red foxes come in all colours ranging from brown to silver, to black.