National Zoo awaits birth of pandemic panda cub

National Zoo's giant panda Mei Ziang
The Smithsonian National Zoo's giant panda Mei Ziang, sleeps in the indoor habitat at the zoo in Washington in August 2015. Zookeepers at the National Zoo are on baby watch after concluding that venerable giant panda matriarch Mei Ziang is pregnant and could give birth this week.
Jacquelyn Martin | AP Photo