Giant panda Ultrasound (1 of 2) (IMAGE) Smithsonian Caption National Zoo Veterinarian Carlos Sanchez performs an ultrasound on giant panda Mei Xiang on May 7, 2008, at the Fujifilm Giant Panda Habitat. Scientists at the Zoo detected a secondary rise in urinary progestin levels in the Zoo's female giant panda Mei Xiang on June 16. This hormone rise is an indicator to Zoo scientists that it should be 40 to 50 days before Mei Xiang either gives birth to a cub or comes to the end of a pseudo pregnancy, or false pregnancy, which is common in giant pandas. Credit Jessie Cohen/Smithsonian’s National Zoo Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.