Sometimes it's hard to say goodbye, especially to an adorable panda bear. Last month, the National Zoo in Washington, D.C., announced that its 4-year-old giant panda will soon leave the zoo. In January or February, the panda, named Tai Shan, is going to China to live.

Giant Panda Tai Shan at the National Zoo in Washington, D.C., around his third birthday in July 2008. (Karen Bleier/AFP Photo/NewsCom)

China owns all the giant pandas living in the United States. Under an agreement between the two countries, any panda born in the U.S. belongs to China.

It must eventually be sent to China to live. Tai Shan was born at the National Zoo in July 2005. His new home will be the Wolong National Nature Reserve in China's Sichuan province.

Cub on camera

Tai Shan's name means "peaceful mountain." When he was born, the National Zoo set up a "panda cam" to record the new baby and his parents. Over the Internet, animal lovers could watch the pandas eat, nap, and play. They fell in love with the adorable cub.

"Tai Shan leaving Washington is terribly sad for the zoo, the community, and his fans around the world," said Steve Monfort. Monfort is acting director of the National Zoo. "We have learned so much from him in just four short years."

Pandas in trouble

Giant pandas are endangered. China is the only country where pandas are found in the wild. Scientists think that only about 1,600 giant pandas still live there. There were once many more. The giant black-and-white bears have lost much of their habitat, or natural home. They live in bamboo forests. Adult pandas eat 40 to 50 pounds of bamboo a day. As humans have cleared bamboo forests, the animals have struggled to survive.

Scientists working together

China loans pandas to zoos in the U.S. and other countries. The Chinese government wants people to learn about the endangered animals. It also wants to help scientists study them. Fourteen pandas now live in the U.S. Scientists in China and the U.S. hope that by learning more about the animals, they can help protect them.