It is hoped the two giant pandas will finally mate this season, after last year's unsuccessful attempts.
Perhaps the biggest obstacle to manoeuvre is the fact that female pandas are fertile for only 40 hours a year, as opposed to the four-month season for males.
Yet while the odds are against the zookeepers, project leaders are calling on all resources to increase the chances of conception.
Director of the giant pandas, Iain Valentine, said: "We have to bring a fair amount of science to the table in order to improve Tian Tian's chances of producing a cub.
"As of Christmas 2013, we again began to collect daily urine samples from Tian Tian; these are being picked up and analysed so that we can monitor two key hormones for breeding purposes - progesterone and oestrogen. So far, as we would expect, there is no big news to report."