One year ago Tai Shan was anything but a giant when he arrived in the US. He was nearly hairless, pink and weighed just 113 grams. But to celebrate his first birthday the giant panda Tai Shan is now an active, 25.4-kilogram cub and the star attraction of the National Zoo, Washington.

"He's like a rambunctious little toddler that loves to get into everything," Suzan Murray, the zoo's chief veterinarian, said on Sunday.

Murray has monitored every development benchmark for the panda since his birth on July 9, 2005. Those included the opening of his eyes, the development of his distinctive markings, his heartbeat, his mobility and even the frequency of his squeals, grunts and barks.

Under the agreement with China which allowed the National Zoo to bring two adult pandas to the US for breeding the cub must be returned to China at two years of age to become part of breeding efforts to preserve the endangered species.

The cub still nurses but he has advanced from milk provided by his mother, Mei Xiang, to eating bamboo. The woody perennial grass is the staple of adult pandas' diets and accounts for more than 90 percent of their nutrition.

"My next challenge is weaning Tai Shan from his mum," said Lisa Stevens, the zoo's curator of pandas and primates.

For his birthday staff prepared a giant fruits-icle for the cub -- frozen mixture of apples, yams, carrots and fruit juices. The recipe is a favorite of his mothers but this was the first such treat prepared for the growing cub.

Tai Shan, whose name means peaceful mountain, routinely awakens before daybreak. After a meal the mother and cub are often seen playing and wrestling. Tai Shan also rolls around in the outdoor paddock and climbs trees much to the delight of zoo visitors.

More than 1.2 million have visited the panda compound since the cub arrived last December and over 21 million people have linked to the panda cam website.

Tai Shan is aware of the scent of his father, Tian Tian, in a separate enclosure and although they're often in visual proximity they don't look at each other at all, said Stevens.

"In the wild, males play no role in the rearing of cubs, so there's no reason for there to be any recognition of who the strange neighbor's scent markings might belong to," explained Stevens.

Only about 1,600 giant pandas remain in the wild and fewer than 180 live in captivity. US zoo officials hope their Chinese counterparts will allow the cub to remain in the United States until it nears breeding age of 5 or 6.

Tai Shan was the product of artificial insemination. Zoo officials hope to breed the adult pandas again in the next year.

(China Daily July 11, 2006)