The San Diego Zoo will send two giant panda sisters to a reserve in China to help in the effort to save the critically endangered species.
Su Lin and Zhen Zhen will leave later this summer, according to zookeepers; Monday will be the last day zoo visitors can see the two pandas.
Giant pandas are on a research loan to the zoo from China to study the species. As part of the loan, China decides where the zoo-born pandas will go after their 3rd birthday.
Su Lin (translation: a little bit of something very cute) was born in August 2005. Zhen Zhen (precious) was born in August 2007. Su Lin was scheduled to depart last year for China but that plan was abandoned after a deadly earthquake shook that country.
Their mother, Bai Yun (white cloud), and brother, Yun Zi (son of cloud), will remain on exhibit in San Diego.
Last week, the zoo had a birthday party for Su Lin, Zhen Zhen and Yun Zi, who turned 1 on Aug 5.
Only 1,600 pandas live in the wild, and 290 are in captive-breeding programs worldwide.