Beijing Zoo hid the death of 2-year-old Shui Ling for more than 20 days, its spokeswoman confirmed Thursday.

The zoo had not wished to share the bad news with the public nor was it under any legal obligation to do so, Ye Mingxia said.

Beijing Zoo covers up panda's death for 3 weeks.[File photo/Sohu.cn]

Borrowed on April 29 last year from Sichuan Province for the 60th anniversary celebration of the People's Republic, Shui Ling was found sick in her house on July 4, Ye said.

Shui Ling died the next morning of acute gut pain.

An autopsy determined the cause of death as mesentery volvulus, a twisting of the intestinal membranes that may block the blood flow resulting in deadly shock if not treated promptly, Ye said.

The zoo had attempted to cover up the death from curious visitors, the Beijing Times reported Thursday.

A woman surnamed Lu was repeatedly told that Shui Ling simply did not feel like coming out. The zoo maintained the fiction until Wednesday after Lu called the conservation and research center in Ya'an and was told the truth.

It should be easy to understand the coverup as "this is how bad news is handled in China," Ye said.

Keeping a panda in captivity costs more than 100,000 yuan (US$14,750) a year, Ye said.

Mesentery volvulus afflicts 10 percent of pandas in captivity, and one or two die of it every year, according to Tang Chunxiang, director of the panda con-servation and research center in Ya'an.

Despite a herbivorous diet, pandas have the digestive system of a carnivore characterized by short, thin bowels and a fragile intestine membrane, he said.

To make up for digestive inefficiency, pandas spend nearly all their waking hours eating bamboo, a grass low in energy and protein.

"It's false logic to blame the animal's physiology," Kati Loeffler, a veterinary advisor to the International Fund for Animal Welfare, said Thursday.

"The digestive system is perfectly designed to meet its needs in the wild," Loeffler said.

Stress, lack of exercise and improper diet could be the real culprits for a high mesentery volvulus rate among captive pandas, Loeffler argued.

"People expect them to breed like rabbits: That's the problem," Loeffler said.

Shui Ling's death came two days after another panda in the Beijing Zoo accidentally crushed her newborn cub on July 3.