Suzanna Hall of San Diego Zoo writes:
"Before that trip to Wolong, I was assisting in a trial study of scent presentations in San Diego, utilizing Bai Yun and Shi Shi. We would present them with a small wooden board, painted with urine collected from bears in Wolong. Ultimately, the purpose of the study was to see what kind of information the bears could extract from the urine scent. Bai Yun could always be counted on to interact with the board for a moment or two, at least giving it a good sniff before moving on to finding her breakfast.
"One day, I presented Bai Yun with a board and was surprised by her response. She sniffed and licked the board, then picked it up and sniffed it again, intensely. She continued to hold the board for some time, sniffing and licking and even performing a flehmen to bring the scent into her vomeronasal organ. Then she started anointing herself with the board, rubbing it over her ears and neck vigorously. In all, she probably spent more than 10 minutes with that board. I couldn't see why her reaction to this scent might have been so strong, so I looked back at the urine vial I had poured the scent from: it was labeled "Dong Dong." Years after leaving Wolong, and long after she had been weaned, Bai Yun seemed to recognize the odor of her mother."
image of the late Dong Dong
An inuit panda production