Pandamonium

There's been a joyful surprise at Japan's oldest zoo: the birth of twin panda cubs.

Giant Panda Shin Shin, 15, gave birth last week at Ueno Zoo in Tokyo, one month before the start of the Summer Olympic Games. It's the first panda birth in four years. The newborns, genders still unknown, join big sis Xiang Xiang, born four years ago.

Pandas are notoriously difficult to breed in captivity, as the females go into heat only once a year and can be picky about partners. When Panda moms have twins, they usually raise only one of them, so zookeepers are making sure that Shin Shin breastfeeds one while the other is kept in an incubator. The cubs will be swapped out from time to time so they both benefit from natural feeding.

Shin Shin and her partner, Ri Ri, arrived at the Tokyo Zoo on loan from China in 2011. China's practice of giving pandas to other countries reportedly stretches back well over 1,000 years. Historical records show the Chinese empress Wu Zetian sent two pandas to Emperor Tenmu of Japan in the year 685. Today, China offers pandas to other nations only as 10-year loans, and all offspring are considered to be Chinese property. Xiang Xiang, Shin Shin, and Ri Ri were all supposed to have returned to China by now, but between requests for extended stays from Tokyo's governor and the pandemic, the family is still in Japan.

Ueno Zoo opened in 1882 on grounds once held by the imperial family. The zoo and its surrounding park are a popular tourist destination. Just five other Pandas have been born at the zoo, and this is the first time for twins.