As Er Shun. an adult female panda at the Calgary Zoo enters the preliminary stages of her reproductive cycle, efforts are underway to capitalize on the brief window for impregnation.

According to zoo officials, members of the Calgary Zoo animal care and veterinary teams will begin monitoring Er Shun’s hormone levels under the guidance of a panda reproductive specialist who has arrived from China.

“It’s that springtime of year when they come into a cycle so we’re just starting to see her begin that cycle where we’re seeing changes in her behaviour and we’re seeing changes in her biology,” said Colleen Baird, the Calgary Zoo's general curator. “She’s getting a swollen vulva and that tells us we should start tracking her hormones to see when she’s going to ovulate.”

The urine and blood samples collected from Er Shun will allow the teams to determine the best time for insemination of the semen freshly collected from Da Mao, the zoo’s male panda, as well as his frozen supply.

“Female pandas only ovulate for three days out of the year so it’s a very small window we have to capture,” said Baird. “We will inseminate her two to three times with that semen.”

Er Shun gave birth to cubs Jia Panpan and Jia Yueyue in October 2015 at the Toronto Zoo. The trio as well as Da Mao, the cubs’ biological father, were relocated to Panda Passage at the Calgary Zoo in March 2018.

The panda parents are on loan from China as part of a 10-year-agreement between the two zoos and the Chinese government and the pair is scheduled to be returned in 2023.

The process of artificially inseminating with Da Mao’s sperm was also utilized to impregnate Er Shun with her Toronto-born offspring. “She doesn’t want him to get near her or mount her. Toronto did some testing and it certainly was not a positive experience.”

“We will have to do artificial insemination with this pair because they’re not compatible.”

Jia Panpan and Jia Yueyue, who were born after the agreement with China was made, are slated to return to China in late 2019.

Baird says that if the zoo’s attempts to impregnate Er Shun prove successful and the fertilized egg successfully implants into the panda’s uterine wall, cubs would likely arrive in approximately four months.

According to the zoo, there are fewer than 1,800 giant pandas left in the wild.

With files from CTV's Bill Macfarlane