CALGARY -- Three grizzly bear cubs arrived at the Calgary Zoo this week after being discovered by Alberta Fish and Wildlife officers in the Crowsnest Pass.

Zoo officials aren't entirely sure what happened to the mother bear, except that she is believed to have been killed following "an aggressive interaction with a human," said Alison Archambault, director of communications.

Grizzly sows generally give birth in January or February, meaning the cubs would be about three to four months old.

They will spend a few days adapting to their new surroundings, said Archambault, then staff will give them a medical checkup and determine their sexes.

Without being brought to the zoo, Archambault said the cubs' chance of survival was quite low.

The plan will now be to find them a permanent home, most likely at a zoo somewhere in North America.

Only a handful of grizzlies have been brought to the zoo since 1966, with the most well-known being resident male Skoki, who was born in the Bow Valley and arrived at the zoo in 1996 after becoming habituated to humans.