Uhhh...
"Giant pandas (also) produce barks, moans, honks, growls, roars and squeals," said Charlton, a postdoctoral research biologist at Zoo Atlanta. "In addition, females produce chirps when they are approaching and entering estrus, and some non-vocal sounds, such as the snort and chomp, which are sometimes heard."
So much for my mental image of prurient zookeepers.
