スミソニアン国立動物園さんのインスタグラム動画 - (スミソニアン国立動物園Instagram)「🐼 On March 15, #MeiXiang started exhibiting behavioral signs that breeding season is approaching! A urinary hormone analysis confirmed that her change in behavior was due to her rising estrogen levels, signaling that the panda breeding season will be here soon. Mei Xiang’s behavioral changes have not been especially subtle, she has broken from her energy-efficient routine of eating and sleeping and is instead much more active. Tian Tian has been following all of these changes vigilantly. Over the weekend, he started bleating at Mei Xiang, one of his ways to communicate that he is interested in her. He also has been spending a lot of time at the howdy window that separates their yards. This week he has been bleating more frequently and has tried to keep Mei Xiang within his sight. Although Tian Tian is very interested in Mei Xiang, she has made it clear with her vocalizations that she is not ready to breed. Keepers are going to continue to monitor the pandas for behavioral changes. Meanwhile, endocrinologists at the Smithsonian Conservation Biology Institute will continue monitoring her hormones to determine when Mei Xiang reaches peak estrus. #PandaStory」3月23日 1時55分