Back in April, Edinburgh Zoo’s female giant panda Tian Tian experienced her once a year ‘fertility window’ – the only opportunity for a successful pregnancy. Although male Yang Guang failed to successfully mate with Tian Tian, the zookeepers opted for artificial insemination after the failure of a more natural process.

Almost four months later, Edinburgh Zoo is cautiously suggesting that there might indeed be a new giant panda on the way – a potential UK first. Talking to BBC, the zookeepers confirm hormonal tests have indicated a possible pregnancy, and Tian Tian has adopted habits and moods often associated with pregnancy.

However, given the panda’s ‘moody’ condition, an ultrasound is not feasible to confirm the pregnancy, with the zoo's Iain Valentine stressing “we’re not going to risk the hand of our vet". ‘Phantom pregnancies’ are a common phenomenon in pandas, so it’s very possible the bear is exhibiting the signs of impending motherhood without actually being pregnant.

Giant pandas – an endangered species - have unusual reproductive habits, which has caused many challenges in terms of conservation. The difficulties include short fertility windows and very fussy mating habits. Zoologists have also been unable to conclusively identify the gestation period. This is as a result of a process known as ‘delayed implantation’, where the fertilised egg remains in the reproductive tract for a certain period of time before implanting in the womb and beginning the process of full growth.

The period between mating and birth has ranged from 95 days to 160, and it has been suggested that this can result in the cub being born in more favourable birthing conditions. Giant pandas also have a high chance of giving birth to twins. Since the zookeepers used several frozen sperm samples for artificial insemination, it's possible that Tian Tian's cubs would have two different fathers.

Any cubs born to Tian Tian will only stay in Edinburgh for two years. The zoo's two adult pandas are on-loan from China, and as part of the loan deal any children born will be transferred to Chinese authorities after their initial stay with the parents in Scotland.

Scotland’s Highland Wildlife Park recently saw the birth of a male red panda cub called Kush.