Officials at the Calgary Zoo are "devastated" after a tiny Siberian tiger cub that was fighting for its life died Thursday night.
Staff believe the female cub succumbed to complications from severe head trauma, similar injuries to those suffered by its sibling who died shortly after birth.
The veterinary team at the Calgary Zoo had been working hard to save the cub, whose birth earlier this week came as a surprise. But the cub's odds of survival were rated 50 per cent or less.
"What we've experienced this week is the harsh reality of nature. The fact that one in three cubs dies soon after birth, both in the wild and in captivity, is of little consolation right now," said Dr. Sandie Black, Head of Veterinary Services.
"We're all devastated."
Dr. Black said the cub, which was born on Tuesday, had received round-the-clock care but didn't make it through her third night of life.
"From birth, her clinical signs were consistent with head trauma and that is how our veterinary team had been treating her while trying to remain hopeful she would recover," Dr. Black said.
Earlier this week Dr. Black said it appeared the death of the first cub was the result of an inexperienced mother.
"We believe she picked up and moved the cub inappropriately. This wasn't an aggressive act at all - just an inexperienced mom. If you think about that image of a cat carrying a kitten around the shoulders - well, she just hasn't got it quite right yet."
Siberian tigers are considered endangered and the population continues to decline. Census estimates indicate there are fewer than 400 adult/sub-adult Siberian tigers left in the wild.
Zoo officials had been unaware that the mother, named Katja was pregnant until she gave birth.
Dr. Black had indicated it was not unheard of for tigers to get pregnant without their handlers knowing.
She said numerous attempts to breed Katja were made last January with a nine-year-old male tiger named Baikal from New York's Bronx Zoo.
"If you think about the relative sizes, our female tiger weighs over 300 pounds - the cubs weigh less than two pounds each. So they are a very small entity in a very large body. Additionally these are Siberian tigers, (they have) a very thick fur coat," Dr. Black said.
"She's a little bit pendulous in the belly and actually there's at least another half-dozen occasions where this has happened in zoos where they haven't been aware of a pregnancy."
Dr. Black said it has been a difficult week for zoo staff, especially veterinary and animal care teams who cared for the tiny cub for every minute of her short life and were so excited about her arrival.