Experts have warned the chances of a panda cub being born at Edinburgh Zoo are fading – as Tian Tian’s ‘pregnancy’ enters its third month.
Staff at the zoo remain optimistic they will see the pitter-patter of tiny paws, but it is still unclear wether Tian Tian is actually pregnant.
Specialists say unsuccessful pregnancies – where the female re-absorbs the foetus – are extremely common.
And, given most cub births take place in late August or early September, concerns are now starting to be aired.
Andy Kouba is director of research and conservation at Memphis Zoo, which has been helping carry out pregnancy tests on Tian Tian.
He said: “It’s relatively common for pandas to lose babies. Our test looked very positive but that does not always mean there will be a successful birth. At our zoo we have had multiple pregnancies in which our female has aborted.
“The zoo will be able to tell if the pregnancy is lost if the hormone progesterone goes baseline and stays that way for several weeks.”
Mr Kouba hopes that isn’t the case with Tian Tian, though, and added: “We’re keeping our fingers crossed that a cub is on the way.”
Panda expert Jeroen Jacobs agrees that, as time goes on, it looks less likely Edinburgh Zoo is about to celebrate the birth of the UK’s first giant panda.
He said: “It is getting very late and this is unusual – everybody expected something to have happened by now.
“One of the things that could have happened is that Tian Tian was pregnant and that she has lost the cub.
“But if that is the case there will be signs in the future that Tian Tian has had a pseudo-pregnancy – it will come out in the end.
“It’s just a case of biology keeping us on our toes and it’s impossible to say. It’s a waiting game.”
Tian Tian was artificially inseminated in April using sperm from Yang Guang and from another male named Bao Bao, who died at Berlin Zoo last year.
If she does give birth, the newborn cub will weigh in at between three to five ounces.
Despite the misgivings, a spokeswoman for the zoo said staff remained hopeful.
She said: “Both pandas are off show at the moment because Tian Tian continues to remain sensitive to noise.
“Everything looks good with her hormone levels and behaviour – as long as it does we will continue to be on panda watch.
“Until something changes or she goes into labour, that won’t change.”
Tian Tian and Yang Guang arrived in December 2011 after a 5000-mile flight from China and became the first giant pandas in the UK for 17 years.