Male Giant Panda Tian Tian is seen at the panda habitat of the U.S. National Zoo in Washington D.C., capital of the United States, Sept. 17, 2012. U.S. National Zoo on Monday announced Giant Panda Mei Xiang has given birth to a cub. The National Zoo now houses Mei Xiang and Tian Tian, a pair of giant pandas on loan from China. [Xinhua]