Two pandas, female Shin Shin and male Ri Ri, arrived in Tokyo from China in February 2011 and went on view to the public soon after a devastating earthquake and tsunami the following month, providing some welcome good news.

Hopes for a baby began after the two pandas were recorded on camera mating earlier this year.

Those hopes have risen further over the past month as 6-year-old Shin Shin began showing signs of pregnancy such as diminished appetite, more time sleeping and hormonal changes.

“At Ueno Zoo we’ve had three panda births, but the last one was in 1988, 24 years ago. So to have a birth for the first time in 24 years is obviously something we’re looking forward to,” said Yutaka Fukuda, vice deputy director at the zoo.

Panda fans have flocked to the zoo to see Shin Shin before she disappears from public view on July 3. The birth could take place any time from July to August.

“I came to the zoo for the first time in a while because I heard there may be cause for celebration soon, and I really wanted to see the pandas,” said 45-year-old Michio Souma.

Although the zoo has already begun preparations for the birth, such as amassing incubators and running “birth drills”, pandas often show false signs of pregnancy and there is no scientific way to confirm that a baby may be on the way.

“We will continue observations, but actually we won’t know until the very last minute, when she has begun giving birth, if this is a false pregnancy or the real thing,” Fukuda said.

“Of course we are hoping for the best.”