After 10 years in the National Zoo, what's a few more? D.C.'s panda power couple, Tian Tian and Mei Xiang, will stick around the capital for another five years after zoo officials signed a new $1 million-a-year deal with the Chinese government. Zoo director Dennis Kelly traveled to China on Dec. 12 to present officials with a plan to study panda cub behavior and and work out the deal. Panda mating habits are notoriously complex and mysterious, and researchers have tried in vain to get Mei Xiang pregnant. But the pair is wildly popular among Washington zoo-goers, who will no doubt be happy to hear about their extended stay.