Specialists at Tokyo's Ueno Zoo have concluded that giant panda Shin Shin, 8, experienced a phantom pregnancy, the zoo said Monday.
According to the zoo, Shin Shin is back to normal after showing signs of pregnancy, including a lack of appetite and reduced activity, that have gradually disappeared since mid-June.
Shin Shin did not give birth despite a test July 11 showing her progesterone had dropped to barely detectable levels. The hormone disappears from the bloodstream when the animals give birth.
The pregnancy period for giant pandas typical lasts 140 days, but that has elapsed since Shin Shin was last observed mating with Ri Ri on March 12, leading to the conclusion that she will not give birth.
Shin Shin began showing reduced appetite and hormone fluctuations in late May and was removed from public display on June 4. She returned on July 2 after a phantom pregnancy was suspected.
Kiyoshi Nagai, Ueno Zoo's public relations manager, said the facility will focus on managing Shin Shin's health ahead of the next breeding season.
