There could be soon be two more walruses at the aquarium in Quebec City.

In what experts say is rare for walruses in a zoological environment, Arnaliaq is due by the end of April and Samka at the beginning of June at the Aquarium du Québec.

But as thrilled as staff at the aquarium are for their two flippered marine mammals, the pregnancies face a huge amount of uncertainty.

There have been only six baby walruses born in North American zoos since 1930. Only 19 female walruses have gestated during that time.

Aquarium staff estimate the babies have a one-in-three chance of survival.

The walruses are now receiving around-the-clock attention, and the aquarium is consulting a team of international experts, the aquarium said in a news release Wednesday.

Emergency care is on standby.

Given the potential scientific, and public, interest in the pregnancies, the aquarium is promising to provide regular updates on its Facebook page.