The UK’s only female panda, Tian Tian, is believed to be pregnant, according to Edinburgh Zoo.
A spokesman for the zoo said it was hard to predict a specific date for any cub being born, and that the breeding season can last until late September.
Tian Tian, who arrived at the zoo as part of a breeding pair with Yang Guang in 2011, was artificially inseminated earlier this year.
The zoo said she was being closely monitored.
This is the fifth time Tian Tian has been artificially inseminated.
She had previously given birth to twins in China but all attempts to produce a cub at Edinburgh Zoo have failed.
A spokesman for RZSS Edinburgh Zoo said: “Giant panda breeding is a very complicated process but we believe that Tian Tian is pregnant.
“Although a specific date was suggested, like all babies it’s hard to predict precisely and the panda breeding season can last until late September.
“Tian Tian is being closely monitored by our expert team and we will be the first to share any news as soon as we can.”
News of the pregnancy came to light after documents were released to the Edinburgh Evening News under the Freedom of Information Act.
If a cub was born, it would be returned to China at the age of two – mimicking natural dispersal age in the wild.
Baby panda facts
- At birth, a cub is just 1,000th of its mother’s weight at about 5.3oz (150g). Giant panda foetuses do not start to develop until the final weeks of gestation
- Panda cubs are born pink and covered in short, sparse white hair, their eyes are tightly shut and they cry loudly and often
- Their black patches start to appear at about one week old, followed by black hair on the patches a few weeks later
- It is several weeks before they can crawl and cubs spend the first few weeks of life vocalising their needs to their mother, sleeping and suckling
- Panda mothers lick their cubs often and do not leave the cub to eat bamboo until offspring are three to four weeks old. At this point the cubs can regulate their body temperatures and do not need constant body contact from the mother to keep warm
- After a month, the cub looks much more like a miniature adult giant panda but with a longer tail
- Baby pandas’ eyes open partly after 30 to 45 days and fully open a week or two later
- Panda cubs grow to up to 10 times their birth weight in the first five to six weeks
Panda reproduction is a notoriously difficult process, with females only ovulating once a year.
Tian Tian (Sweetie) and Yang Guang (Sunshine) are the only giant pandas living in the UK.
They arrived on loan from China in December 2011 and are due to remain at Edinburgh Zoo for a decade.
The zoo first announced it was in negotiations to bring a pair of giant pandas to Scotland in 2008.
The pair were brought to the UK under a historic agreement between the UK and Chinese governments.
Described as a gift from China, they were the first giant pandas to live in the UK for 17 years.