The Calgary Zoo gorilla troop is growing.

Kioja, who turns 15 years old this month, is pregnant and showing.

gorilla ultrasound

An ultrasound image of the baby gorilla. (Calgary Zoo)

"Gorillas do have a bit of a pot-belly. But if you know Kioja, you would be able to tell she's expecting," said Malu Celli, a curator at the Calgary Zoo.

The sixth member of the gorilla family is expected to arrive in early March.

Celli says Kioja was trained to stand still for ultrasounds even before she got pregnant so they could monitor the health of her baby.

"She won't stay for as long as a human mom would but it's enough for us to know everything is OK."

Celli say the zoo's veterinarians won't be able to determine the gorilla's sex before birth, but say it's growing strong and has a healthy heartbeat.

This will be the first offspring for Kioja, who was born in captivity at the Bronx Zoo in 2001.

"She wasn't raised by her mother," said Celli.

"We are hoping that she would know what to do once the little one comes but we're not taking any chances and we're really getting ready if we need to step in." 

The anticipated gorilla baby was sired by the troop's silverback, 37-year-old Kakinga. He has fathered nine offspring born at the Calgary Zoo — seven of them are still alive.

"He's actually quite gentle and very interested in the kids," said Celli.

pregnant gorilla Calgary Zoo

The Calgary Zoo trained Kioja how to accept an ultrasound even before she got pregnant. (Calgary Zoo)

The zoo is unsure when the public will be able to view the new addition.

"It depends on how Kioja does. If she delivers in front of the public, and looks after the baby — technically everybody can be there and see this."

Another new addition to the Calgary Zoo in 2016 is a female snow leopard from a European zoo. She will be joining the lone male and introduced to the public next week.