March 10, 2013. A female giant panda Ke Lin watching a panda mating video at Chengdu Research Base of Giant Panda Breeding, Sichuan province, in this handout still image taken from video. According to the staff of the research base, they showed Ke Lin this video trying to let her know how to mate as she kept rejecting her mate panda Yong Yong from mounting her although she was in oestrum. After watching this video, Ke Lin and Yong Yong successfully mated.