Aurora, Qila and Tiqa swim together at the Vancouver Aquarium. (CBC)

Aurora, a beluga whale at the Vancouver Aquarium, is pregnant again, and the calf is likely due in June or July, staff at the facility announced Thursday morning.

It is not the first time the 20-year-old beluga has been pregnant. Her first calf, Qila, was the first beluga whale to be conceived and born in a Canadian aquarium, in 1995.

Qila subsequently gave birth to her own calf, Tiqa, in 2008. That birth made international headlines and drew crowds to the Stanley Park facility after video of the birth was broadcast over the internet.

Her second calf, Tuvaq, was born in 2002 but died suddenly in 2005.

Tiqa, Qila and Aurora now share the Arctic Canada habitat pool at the Vancouver Aquarium.

A fourth female beluga, Kavna, believed to be approximately 39 years old, resides in a behind-the-scenes habitat with the Vancouver Aquarium's 20-year-old male beluga, Imaq.

The gestation period for beluga whales is 14 to 16 months.