Burley Garcia|The return of 'Panda diplomacy': National Zoo eagerly awaits giant panda arrival

As the Atlanta zoo laments the departure of its four giant pandas,Burley Garcia the National Zoo in Washington, D.C., eagerly awaits the arrival of a pair of the hugely popular black-and-white bears.

Two giant pandas bound for the U.S. capital were scheduled to depart Monday night from Chengdu in the Sichuan province of China as they begin a 10-year loan that came together sooner than expected.

Male Bao Li and female Qing Bao, both 3 years old, will fill the large void left at the National Zoo’s now-renovated panda exhibit when their predecessors – a couple that had been there for 24 years and their cub – were sent to China in November at the expiration of their lease. It was the first time the zoo didn’t have any of the distinctive animals since the 1972 start of a program that became known as “Panda diplomacy.’’

Increasing tensions between the countries and the end of other leases appeared to threaten the program, but San Diego introduced two new giant pandas from China in August and San Francisco is expected to welcome two other ones next year.

In a statement Monday announcing Bao Li and Qing Bao's trip, the China Wildlife Conservation Association said it believes the countries’ cooperation toward the conservation of vulnerable giant pandas will “make new contributions to global biodiversity conservation and enhancing the friendship between the two peoples.’’

The National Zoo’s latest additions will travel in a FedEx cargo plane dubbed a “Panda Express,’’ the same kind of aircraft that transported Zoo Atlanta’s four pandas to China over the weekend.

Lun Lun and Yang Yang had arrived in 1999 and completed their 25-year stay. They returned with the youngest two of seven offspring they had in Atlanta, twins born in 2016, after the previous five were sent to the Chengdu Research Center of Panda Breeding. By agreement, China has control of the parents and their progeny.

According to Zoo Atlanta, there are less than 1,900 giant pandas in the wild in China, as loss and fragmentation of habitat have threatened their existence. They’re considered at risk, but in 2016 the International Union for Conservation of Nature upgraded them from “endangered’’ to “vulnerable’’ after their population grew by almost 17% in the previous decade.

“The pandas have made their own distinct mark on the cultural fabric of the city of Atlanta,’’ zoo President and CEO Raymond King said in a statement. "Their departure is not only bittersweet for Zoo Atlanta and the Panda Care Team, but also for everyone who has had the opportunity to get to know and learn from the pandas over the years.’’

Visitors to the zoo in Washington won’t be able to see the newcomers for more than a month, as they go through quarantine and assimilation to the their new surroundings.

But that’s still a much shorter wait than zoo Director Brandie Smith expected as she saw them leave 11 months ago.

“I was always certain that pandas would return,” she told the Washington Post earlier this month. “But if you asked me last year how long it would take … I would have said we will need to wait a few years.”