Everything you always wanted to know about panda sex (but were afraid to ask) | Sam Knight

After years of disappointment, staff at Edinburgh zoo hoped that this month would bring the birth of a baby panda. But is captive breeding really the way to save the species?

At about 5pm on 25 March, a cold, wet Wednesday earlier this year, Tian Tian, the female giant panda at Edinburgh zoo, stirred from the wooden platform in her outdoor enclosure and began to bleat. Tian Tian, who was born in Beijing zoo in 2003, has proved a terrific hit with visitors since she arrived in Britain with the zoo's male panda, Yang Guang, in December 2011. Yang Guang, whose name means "Sunshine", might be a larger and, to all appearances, more affable creature, but Tian Tian ("Sweetie") is a panda with more edge, more wit and more dash.

These are unusual qualities. Pandas are vegetarian bears with slow metabolisms. They subsist almost entirely on bamboo, which they digest poorly. They do everything they can to avoid unnecessary exertion. If you give Yang Guang a ball, he will most likely see if he can eat it, then let it go. Tian Tian, on the other hand, has been known to skip after balls and do forward rolls. Sometimes she hangs from the bars on the top of her indoor den - a pose that her handlers call "ninja panda" - just for the hell of it. She is not all nice. Tian Tian has bullied keepers off the job, and sometimes takes sly swipes with her enormous claws at passing vets. "She has got her own mind, most definitely," said Alison Maclean, the chief panda keeper at Edinburgh zoo, who seems to love her deeply for precisely this reason. "You have to be very, very careful around her."