The clock is ticking, and the heat is on. A giant male panda loaned to Britain by China has just 36 hours to make his move on his female companion or he'll have to wait another year.
Conservationists at Edinburgh Zoo in Scotland put Yang Guang together in the same enclosure as Tian Tian on Wednesday after months of monitoring the female panda's hormones and behaviour.
Over the past week, she has been calling out to Yang Guang, going up to the grate that separates their enclosures and spending time in her pond to cool off, while her hormone levels have also been changing.
But he will have to move fast as the two pandas, which were brought over from China in December, are being put together for just 15 minutes at a time -- any longer and they are likely to start fighting.
Experts concede that the normally placid bamboo-munching animals may start attacking each other immediately in any case.
"We have hopes that they will breed, but it's totally up to them," said the zoo's director of research and conservation, Iain Valentine.
"Our expert keepers will be on hand to separate the two bears if the sparks fly just a little too much, as at the end of the day, both are powerful and dangerous animals and it's not uncommon for pandas to attack each other after or instead of mating."
If they get on, they will be put together up to three times on the first day, and then again on the second day. If that fails, the zoo will look at whether Tian Tian can be artificially inseminated.
While natural breeding in captivity has proved difficult, insemination has a better track record -- the Wolong Breeding Centre in China, for example, has produced 94 cubs using this method since 2006.
The zoo will not be able to confirm if the panda is pregnant until July, and if she isn't, they will have to wait again until next year, or the year after that -- Tian Tian and Yang Guang are on loan to Scotland for the next decade.
Explore further: Flocks of starlings ride the wave to escape