Giant panda Ding Ding enjoys a birthday meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

The Moscow Zoo on Sunday celebrated the birthdays of two giant pandas Ding Ding and Ru Yi. Six-year-old male Ru Yi was born on July 31, 2016 whereas five-year-old female Ding Ding was born on July 30, 2017. 

The pair arrived in Moscow in 2019 from China's southwestern province of Sichuan for a 15-year joint research program.

READ MORE: Panda twins celebrate 2nd birthday in Chengdu

Giant panda Ding Ding enjoys a birthday meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ding Ding plays with a toy at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ru Yi at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ru Yi enjoys a meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ru Yi enjoys a birthday meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ding Ding enjoys a birthday meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ding Ding at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ding Ding feeds on bamboos at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ding Ding feeds on bamboos at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ru Yi at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ru Yi at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ru Yi enjoys a birthday meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ding Ding at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Giant panda Ru Yi enjoys a birthday meal at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ding Ding at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)

Visitors look at giant panda Ru Yi at the Moscow Zoo in Moscow, capital of Russia, on July 31, 2022. (PHOTO / XINHUA)