The trouble with Pandas when it comes to mating are some seriously long odds
Pandas in the wild are solitary creatures as they roam from one forested bamboo patch to the next. Once a year they come into estrus and at this time, females will go to the outskirts of their ranges and rub their anal area on trees and rocks to deposit smelly secretions from their anogenital glands. Males do much the same to let the female know who is in the neighborhood. The female panda will except a mate for the brief period of approximately 24 to 38 hours if he has all the right moves. Now I'd call that a very small fucking window.
On top of that, the male giant panda has one of the smallest penises relative to body size in the entire animal kingdom.
A willing female must get into the lordosis posture, in which she lowers her front end, arches her back down and raises her tail end up, putting her vaginal cavity in the right position for the male to enter her from behind. And once he obtains the position, she has to shove on to him,
After orgasm, both male and female giant pandas bleat, or let out a goat-like cry. The male will then do a "roll back," in which he sits on his butt and lower pelvic area and pulls the female so that she's sitting on him — and holds on as long as he possibly can. It's unknown why the male does this.
He may hang a bit and try to possibly mate with the female a few more times.
I've watched Mei Xiang and Tian Tian attempt to mate a few times and it was mostly bleating's and Mei backing up to Tian Tian, who backed up from Mei Xiang. No joy.