Qila, a 12-year-old beluga whale, successfully gave birth at the Vancouver Aquarium, Tuesday afternoon.

"The baby looks very strong did just what babies are supposed to do,'' said John Nightingale, a spokesman for the aquarium.

"It popped out tail first, swam to surface, took a nice big breath, popped back five seconds later and took another one. So that's the first milestone,'' he said. "The baby's been swimming all over the place.''

Aquarium officials say they are virtually certain that the baby whale is a girl.

Before giving birth, Qila had been pregnant for 15 months.

In preparation for the birth, two other belugas, including the calf's father Imaq, were relocated to another pool to give Qila more room.

This is to ensure that there are no distractions during the labour and after birth that would prevent Qila from establishing a nursing pattern with her newborn calf.

However, Aurora, Qila's mom, will stay with her as a companion.

Once the calf is visible, the birth will take about two to four hours to complete.

Imaq and another beluga whale called Kavna will return to join Qila and her calf once the aquarium staff are certain that mom and the calf are ready to widen their social circle.