Hong Kong Ocean Park announced on Tuesday that female giant panda Ying Ying has started displaying typical pregnancy symptoms.

Ocean Park has artificially inseminated Ying Ying by using male giant panda Le Le's fresh semen and An An's frozen semen to increase the chance of pregnancy, after Ying Ying and Le Le failed in their natural mating attempts during the breeding season, which was around late March to early April.

Howard Chuk, Senior Curator of Terrestrial Life Sciences of Ocean Park, said that since early July, Ying Ying has started displaying some typical pregnancy symptoms, including reduced food intake, increased resting time, a swollen vulva, and corresponding hormonal changes.

These symptoms, however, can also be indication of pseudo-pregnancy, Chuk said, adding that the park will continue to work closely with experts from the China Conservation and Research Center for the Giant Panda in Wolong of Sichuan Province to follow Ying Ying's condition.

"We hope to bring some good news to the people of Hong Kong this year," Chuk said, telling the media that the gestation period of giant pandas can last from around 70 to 300 days.

Ocean Park started to arrange mating opportunities for Ying Ying and Le Le since 2011 and Ying Ying had experienced pseudo-pregnancy.

There are a total of three giant pandas in Ocean Park, with Ying Ying and Le Le turning 12 this month, and An An, at the age of 31, has officially become the world's oldest male giant panda under human care.