According to zoo officials, in July, her levels of “urinary progesterone began to rise and that indicated that she would give birth to a cub or experience the final stages of pregnancy within 6 to 8 weeks.”
In August, zoo keepers started to watch her closely. Mei Xiang’s behavior began to change and she became sensitive to noise, prompting officials to close the panda house. Ultrasounds were performed several times a week to look for changes in her uterus.
But it wasn’t meant to be.
Veterinarians didn’t see a fetus on any ultrasounds and her hormone levels and behavior are returning to normal, officials said.
It isn’t atypical for female giant pandas to have pseudopregnancies that can last between three to six months — just like a real panda pregnancy.
Mei Xiang has given birth to three surviving cubs with Tian Tian. All of the cubs were born at the zoo. Her first cub, Tai Shan, was born in 2005, and her second cub, Bao Bao, was born in 2013. Both live in China.
Her third cub, Bei Bei, was born in 2015 and is expected to go to China in the coming months. All panda cubs born at the zoo move to China when they are about 4 years old as part of an agreement between the countries.
“We’ve been watching her hormones for months,” said zoo spokeswoman Devin Murphy. “This is one of the things that can happen for . female pandas. Their hormones can be the same whether they are having a pregnancy or a pseudopregnancy, which is why we monitor her so closely.”
For visitors who typically go in droves to see a new panda cub and follow it on the panda cam, the news will be disappointing.
“It’s always special and exciting to have a panda cub,” Murphy said. “We’ve been lucky to have three born here. This year, it looks like we won’t have one.”
At 21, Mei Xiang is considered to be at “advanced maternal age,” zoo officials said, but they said giant pandas older than her have had cubs. It’s not known whether she will breed next year. Zoo experts will consult with their counterparts in China, Murphy said.
Mei Xiang will likely return to her “normal routine” within a few weeks, her keepers said. The panda house reopened Wednesday.