Fans at National Zoo in US bid farewell to three pandas

For zoo visitors from the US capital and beyond, saying goodbye to the pandas was not easy.

One zoo-goer identified as DC Panda Girl wrote, "Dear Mei Xiang, Tian Tian, and Xiao Qi Ji — I have dreaded this post for quite awhile, living in denial and hoping this day would somehow never come. Because saying goodbye to you is the hardest thing I've ever had to do.

"You may never know it, but you have given me so much over the years. You gave me a reason to smile, to laugh and to find joy, even in some of my darkest moments. You provided comfort and support in a way that humans simply could not," her letter continued.

Brandie Smith, director of the Smithsonian's National Zoo and Conservation Biology Institute, said that as the family of three departed for their new home in China, they left behind a "tremendous" legacy in Washington.

"It is exciting and humbling that people around the world have followed these pandas, shared in our joys and rooted for our success," Smith said. "As this chapter of our giant panda program closes, we remain committed to the conservation of this species and look forward to continued collaboration with our Chinese colleagues."

Asked how she would cope with having an empty panda habitat at the zoo, Smith said she would immediately think about the future, working with colleagues to bring pandas back.

What will she tell visitors who want to know when they might expect new pandas?

"I will say that they have to wait the same as I do until we know that information for sure," Smith told China Daily.

"We have a great relationship with our colleagues in China, and we look forward to working together to bring them back," she added.

More than 2 million visitors travel to the zoo each year, and giant pandas are at the top of their watch list.

In an interview with China Daily in August, Smith said the absence of the bears may mean that the other animals will get "a little extra" attention.

In 2000, China and the United States signed a Giant Panda Cooperative Research and Breeding Agreement for the second pair of giant pandas, Mei Xiang and Tian Tian, to stay at the zoo for a decade, starting on Dec 6 that year.