One of the Toronto Zoo's giant pandas on loan from China is pregnant, and may be expecting twin cubs.
The zoo made the announcement on Facebook Wednesday morning, saying a fetal heartbeat was detected on Friday, Sept. 25. The zoo said a vet checked the bear again on Tuesday, and captured an image of what may be a second panda fetus.
"While this is very exciting news, we remain cautiously hopeful as the next three weeks are critical," the zoo said on Facebook.
"Zoo staff and panda experts will continue to monitor Er Shun."
The zoo posted photos of the bear's ultrasounds on Facebook, and uploaded the video to YouTube.
Maria Franke, the zoo's curator of mammals, said staff members were surprised when they saw the ultrasounds.
"We were hugging and dancing all over the place," Franke told CTV Toronto's Janice Golding on Wednesday.
The 8-year-old panda, named Er Shun, underwent two non-surgical artificial inseminations in May as part of a worldwide giant panda captive breeding program.
Zoo officials said the procedure was necessary because the lumbering female wasn't "jiving" with her male partner, 7-year-old Da Mao. Reproductive scientists used sperm collected from Da Mao, as well as frozen sperm from two giant pandas living in China.
Giant pandas have what is called "delayed implantation," with a gestation period that can last anywhere from 87 to 186 days from insemination. As a result, scientists don't know whether females are expecting until approximately 20 days before they give birth.
Er Shun and Da Mao are on loan to Canada from China for 10 years, five of which are being spent in Toronto, and five which will be spent in Calgary. Any cubs born to the bear couple will remain in Canada.
The mother and baby have to be together for two years before the cubs can be weaned, so if Er Shun has more cubs, her stay at the Toronto Zoo will be extended past 2018.
Er Shun was artificially inseminated in April 2014, but that attempt was unsuccessful.
