A female giant panda at Tokyo’s Ueno zoo has shown signs of being pregnant, including reduced appetite and longer sleeping times, the zoo’s operator said.

If 11-year-old Shin Shin does give birth, the cub will be the first giant panda born at Ueno Zoological Gardens in five years.

On Friday, the zoo put Shin Shin on public display for the first time since February, when she was housed together with male panda Ri Ri, also 11, after she appeared to be in heat.

The pair arrived from China in February 2011 and went on view soon after the devastating earthquake and tsunami in March 2011. Their debut provided a welcome distraction from the daily doses of bad news emerging from the Tohoku region and the crippled Fukushima No. 1 nuclear plant.

The birth of Shin Shin’s cub in 2012 marked the first time a panda had been born at Ueno zoo in 24 years and was greeted with widespread excitement.

But the tiny cub was later found motionless and without a heartbeat on his mother’s belly and, although it was moved to an incubator, efforts to revive it failed.

“The previous cub died after six days. Raising them at the early stage is very difficult, so we want to properly prepare,” Hirofumi Watabe, the deputy head of the zoo, said.

Shin Shin showed signs of being pregnant in 2013, but the event was a phantom pregnancy.

The zoo, in Tokyo’s Taito Ward, said that Shin Shin’s consumption of bamboo sprouts began to fall from around Tuesday and that she is sleeping and resting more.

On Feb. 27 zoo officials confirmed that the pandas had mated three times.

Panda pregnancies, rare in captivity and outside of China, are hard to achieve or predict. If Shin Shin is pregnant, she is likely to give birth in early June or soon after.

“Last time it didn’t turn out well, but I think it will be OK this time,” said Rie Nishimura, 40, who was in the crowd with her 3-year-old daughter, Koharu, watching the panda on Friday.