Experts at Edinburgh Zoo in Scotland have begun daily check-ups of Britain's only female giant panda Tian Tian and male partner, Yang Guang, as the mating season approaches.
The zoo is hoping to put behind the disappointment of last year, when Tian Tian suffered a late-term miscarriage after being artificially inseminated, and is looking out for signs that the pair are ready to mate.
"Tian Tian and Yang Guang are both in great health and condition and things are progressing nicely," explained Iain Valentine from the Royal Zoological Society of Scotland (RZSS), which runs the zoo.
"The giant pandas are clearly showing an increased interest in one another, both pandas are fairly regularly scent marking now and we've also seen food intake increase in both pandas as they seek to drive their body weight up - all fantastic instinctive pre-breeding behaviours.
"Similar to last year, alongside our own experts, RZSS is working together with a number of global colleagues on the complex science that goes on behind the scenes. Natural mating will be attempted, likely followed by artificial insemination as recommended by our Chinese colleagues," he added.
The zoo acquired Tian Tian, whose name means Sweetie, and Yang Guang (Sunshine) from China in December 2011 but the pair have so far failed to mate.
Tian Tian was artificially inseminated in April last year, but the zoo announced she had lost her cub in October.
Pandas, whose natural habitat lies in mountainous southwestern China, have a notoriously low reproductive rate and are under pressure from factors such as habitat loss. China has about 1,600 pandas living in the wild.
Their normal breeding season is mid-April to May.