Edinburgh zoo pandas could mate 'within weeks' Edinburgh Zoo's two giant pandas could be ready to mate within the next month, according to experts. Both Tian Tian ("Sweetie") and Yang Guang ("Sunshine"), who were introduced to each other last April, have started to show important behavioural changes indicating their readiness to breed, panda specialists at the zoo say. Yang Guang has recently begun doing handstands against trees, walls and rocks, allowing him to leave scent markers as high up as possible - a known display of virility. Meanwhile Tian Tian has started calling out, a common behaviour during breeding season. Edinburgh Zoo - where the pandas have lived since their arrival from China in December 2011 - has employed a number of tricks to synchronise the breeding cycles of the pandas, including controlling the lighting and swapping their enclosures. While the behavioural signs are positive, so far no hormonal changes have been detected in either of the animals.