Officials at Ueno Zoo in Tokyo said Wednesday that a female giant panda on loan from a zoo in Mexico City was artificially inseminated with sperm from an Ueno Zoo panda last week.
The procedure, undertaken July 14, was the second artificial insemination involving 18-year-old Ling Ling, the only panda in the Tokyo zoo, and 17-year-old Shuan Shuan from Chapultepec Zoo in the Mexican capital. The first trial in February ended in failure.
Shuan Shuan was flown to Japan in December for breeding, while Ling Ling made three trips to Mexico between 2001 and 2003.
However, Ling Ling's three breeding forays with Shuan Shuan and two other female pandas at Chapultepec Zoo all failed, as well as the February mating at Ueno Zoo.
Ueno Zoo conducted the latest insemination attempt after the pandas showed increased hormonal levels, indicating they were in heat.
Zoo officials conducted the insemination procedure on July 14, when their hormonal levels peaked.
If any cubs are born, the firstborn will be sent to the Mexican zoo and the second one will go to Ueno Zoo, the officials said earlier.