In this photo provided by the San Diego Zoo shows giant panda Yun Zi Monday, Jan. 31, 2011, atop a tree while his mother, Bai Yun, ate her bamboo in an adjacent exhibit at the San Diego Zoo in San Diego. The 79-pound panda Yun Zi is on the way to independence as he reaches a new milestone — 18 months old. The two are spending their mornings alone and, for the moment, still come together in the afternoons. Their behavior will dictate when the gate is shut between them for the last time. (AP Photo/San Diego Zoo, Tammy Spratt)

In this photo provided by the San Diego Zoo shows giant panda Yun Zi Monday, Jan. 31, 2011, atop a tree while his mother, Bai Yun, ate her bamboo in an adjacent exhibit at the San Diego Zoo in San Diego. The 79-pound panda Yun Zi is on the way to independence as he reaches a new milestone — 18 months old. The two are spending their mornings alone and, for the moment, still come together in the afternoons. Their behavior will dictate when the gate is shut between them for the last time. (AP Photo/San Diego Zoo, Tammy Spratt)

One of two newly born panda bears reacts in an incubator at the Zoo in Madrid, Friday, Oct. 8, 2010 in Madrid, Spain. The giant panda cubs, born last month were conceived using artificial insemination. The gender of the cubs is still not known. (AP Photo/Paul White)

One of two newly born panda bears reacts in an incubator at the Zoo in Madrid, Friday, Oct. 8, 2010 in Madrid, Spain. The giant panda cubs, born last month were conceived using artificial insemination. The gender of the cubs is still not known. (AP Photo/Paul White)

This picture taken on Tuesday, Sept. 7, 2010, and released on Wednesday, Sept. 8, 2010, shows a person feeding one of the two giant panda cubs born at Madrid’s Zoo on Sept. 7, 2010. An artificially inseminated female giant panda named Hua Zui Ba gave birth to the two panda cubs. (AP Photo/Spanish National Research Council) Read more →

This picture taken on Tuesday, Sept. 7, 2010, and released on Wednesday, Sept. 8, 2010, shows a person feeding one of the two giant panda cubs born at Madrid’s Zoo on Sept. 7, 2010. An artificially inseminated female giant panda named Hua Zui Ba gave birth to the two panda cubs. (AP Photo/Spanish National Research Council)

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In this photo taken Saturday, Sept. 4, 2010, captive-bred panda Cao Cao carries her one-month-old cub at the Hetaoping semi-wild training base of the China Panda Research and Protection Center in Wenchuan, southwest China’s Sichuan province. Cao Cao delivered the cub last month and had been raising it in a wild environment as part of measures to reintroduce the Giant Pandas back to the wild. (AP Photo)

In this photo taken Saturday, Sept. 4, 2010, captive-bred panda Cao Cao carries her one-month-old cub at the Hetaoping semi-wild training base of the China Panda Research and Protection Center in Wenchuan, southwest China’s Sichuan province. Cao Cao delivered the cub last month and had been raising it in a wild environment as part of measures to reintroduce the Giant Pandas back to the wild. (AP Photo)

In this Friday Sept. 3, 2010 photo, twin panda cubs cry in an incubator at the Wakayama Adventure World at Shirahama, southwestern Japan. The cuddly twins, born on Aug. 11, 2010, will make their public debut on Saturday Sept. 4, 2010. (AP Photo/Kii Minpou via Kyodo News)

In this Friday Sept. 3, 2010 photo, twin panda cubs cry in an incubator at the Wakayama Adventure World at Shirahama, southwestern Japan. The cuddly twins, born on Aug. 11, 2010, will make their public debut on Saturday Sept. 4, 2010. (AP Photo/Kii Minpou via Kyodo News)

A poodle with its fur dyed to look like a giant panda is displayed at a pet fair, Friday Sept. 3, 2010 in Shanghai, China. (AP Photo/Eugene Hoshiko)

A poodle with its fur dyed to look like a giant panda is displayed at a pet fair, Friday Sept. 3, 2010 in Shanghai, China. (AP Photo/Eugene Hoshiko)

In this photo taken with a surveillance camera and provided by the Schoenbrunn Zoo, female giant panda Yang Yang holds her newborn cub in an enclosed compound in Vienna, on Monday, Aug. 23, 2010. Yang Yang gave birth to her second cub on the third birthday of her first baby — called Fu Long — who has since left for China. (AP Photo/Schoenbrunn Zoo, Handout) Read more →

In this photo taken with a surveillance camera and provided by the Schoenbrunn Zoo, female giant panda Yang Yang holds her newborn cub in an enclosed compound in Vienna, on Monday, Aug. 23, 2010. Yang Yang gave birth to her second cub on the third birthday of her first baby — called Fu Long — who has since left for China. (AP Photo/Schoenbrunn Zoo, Handout)

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In this photo provided by the San Diego Zoo, the youngest panda at the San Diego Zoo eats a birthday cake made of ice, bamboo and apples to celebrate his first birthday on Thursday, Aug. 5, 2010 in San Diego. (AP Photo/San Diego Zoo, Tammy Spratt)

In this photo provided by the San Diego Zoo, the youngest panda at the San Diego Zoo eats a birthday cake made of ice, bamboo and apples to celebrate his first birthday on Thursday, Aug. 5, 2010 in San Diego. (AP Photo/San Diego Zoo, Tammy Spratt)

In this photo released by China’s Xinhua news agency, twin baby pandas are seen in Chengdu, southwest China’s Sichuan province, on Friday Aug. 6, 2010. A panda named Qizhen gave birth to the twin baby pandas Friday afternoon in Chengdu, Xinhua said. (AP Photo/Xinhua, Zhang Yujun)

In this photo released by China’s Xinhua news agency, twin baby pandas are seen in Chengdu, southwest China’s Sichuan province, on Friday Aug. 6, 2010. A panda named Qizhen gave birth to the twin baby pandas Friday afternoon in Chengdu, Xinhua said. (AP Photo/Xinhua, Zhang Yujun)

Under a canopy of bamboo, Mei Xiang, one of the National Zoo’s pandas, eats a fruit popsicle on a warm summer day in Washington, on Wednesday, July 7, 2010. (AP Photo/Jacquelyn Martin)

Under a canopy of bamboo, Mei Xiang, one of the National Zoo’s pandas, eats a fruit popsicle on a warm summer day in Washington, on Wednesday, July 7, 2010. (AP Photo/Jacquelyn Martin)

Tian Tian, one of the National Zoo’s pandas, wipes his face while eating a fruit popsicle on a warm summer day at the zoo in Washington, on Wednesday, July 7, 2010. (AP Photo/Jacquelyn Martin)

Tian Tian, one of the National Zoo’s pandas, wipes his face while eating a fruit popsicle on a warm summer day at the zoo in Washington, on Wednesday, July 7, 2010. (AP Photo/Jacquelyn Martin)

In this photo provided by the San Diego Zoo, Yun Zi, a 8-month-old panda cub, embraces one of his toys this morning at the San Diego Zoo on Monday May 24, 2010. The toy, and others like it, was made possible through donations from an online baby shower for Yun Zi and his family. (AP Photo/San Diego Zoo, Ken Bohn)

In this photo provided by the San Diego Zoo, Yun Zi, a 8-month-old panda cub, embraces one of his toys this morning at the San Diego Zoo on Monday May 24, 2010. The toy, and others like it, was made possible through donations from an online baby shower for Yun Zi and his family. (AP Photo/San Diego Zoo, Ken Bohn)

A panda seems so thrilled to see visitors at the Beijing Zoo. (Ellen Creager/Detroit Free Press/MCT)

A panda seems so thrilled to see visitors at the Beijing Zoo. (Ellen Creager/Detroit Free Press/MCT)

In a Wednesday, Feb. 3, 2010 file photo, Mei Xiang rolls herself down a snowy hill at the National Zoo in Washington. The National Zoo says Mei Xiang is not pregnant after all. The zoo says a final ultrasound and hormone analysis late Tuesday, April 27, 2010 confirmed Mei Xiang was experiencing a pseudo pregnancy over the past several months. (AP Photo/Jacquelyn Martin, File) Read more →

In a Wednesday, Feb. 3, 2010 file photo, Mei Xiang rolls herself down a snowy hill at the National Zoo in Washington. The National Zoo says Mei Xiang is not pregnant after all. The zoo says a final ultrasound and hormone analysis late Tuesday, April 27, 2010 confirmed Mei Xiang was experiencing a pseudo pregnancy over the past several months. (AP Photo/Jacquelyn Martin, File)

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