Both pandas, female Tian Tian (Sweetie) and male Yang Guang (Sunshine,) have started to display significant changes in their behavior which are seen as indications of their readiness to mate soon, the zoo's panda specialists told The Guardian newspaper.
Yang Guang has recently begun doing handstands against trees, walls and rocks, scent-marking as high up as possible, considered a display of virility, the panda experts said.
For her part, Tian Tian has begun calling out to Yang Guang, a behavior often seen during breeding season, they said.
The pandas arrived at the Edinburgh Zoo from China in December 2011.
"We're delighted that both Tian Tian and Yang Guang have started to scent mark and call, both clear behavioral indicators of courtship and mating behavior," Iain Valentine of the Royal Zoological Society of Scotland said.