CALGARY -- The Calgary Zoo confirms the two giant pandas on loan to the zoo have departed Calgary, destined to return their homeland of China.

A Lufthansa Cargo flight with the pandas on board left Calgary shortly after 5 a.m. Friday.

Difficulties securing fresh bamboo amidst the pandemic prompted the zoo to begin arranging the return of Er Shun and Da Mao in the spring, but red tape delayed their departure for months.

The giant pandas, which require a total of 40 kilograms of bamboo each day, remained in their enclosures at the Calgary Zoo but not on display, as the Panda Passage building was closed to the public.

The animals arrived at the zoo in March 2018 alongside Jia Panppan and Jua Yueyue — two pandas that were born at the Toronto Zoo in 2015 during the first stop of Er Shun and Da Mao's Canadian visit — and were originally scheduled to spend five years in Calgary.

Jia Panapan and Jia Yueyue were sent to China in early 2020 to participate in a breeding program.

The pandas' time in Calgary was extended as a result of international permit delays.

Calgary Zoo officials confirm the permits have been secured and the pandas have departed.