The wild animals in Pu'er Sun River National Park don't know when it's time for physical examinations, as the goal of the workers is to be as inobtrusive as possible.

For example, to collect information about red pandas - which like to hold onto peoples' legs - the workers attach measuring rods to their legs and wait for the pandas to cling to them.

The lorises may seem very listless, but they will quickly climb onto a scale if they can grab some bananas.

A heavy rhinoceros is drawn onto scales with piles of excrement, and workers are even able to collect samples of urine to test the animal's hormones.

To rebuild the rhinoceros groups, the park has introduced seven white rhinoceroses from Africa and will release them into the wild if the groups can be successfully rebuilt.

According to the park, the rhinoceroses are still growing into adulthood, so the physical examinations are essential to tracking their progress.

"We've had to deal with many emergencies and many difficult situations," said Qian Fuchun, deputy director of the park's animal caring department.

"To avoid possible injury to the workers, all staff are graduates from animal husbandry or veterinary medicine and they also need to receive two or three months of training."

According to the park, any examination methods that harm the animals, such as anesthesia or restraining them, will not be adopted.

Staff have designed various methods to examine the wild animals, including the shy egrets, naughty gibbons and heavy black bears.

On Sunday, China launched its first survey of many of the protected wild animals in the park, including the physical examination and distribution of different species.

The species investigation is slated to last one year.

The Pu'er Sun River National Park, which is 28 kilometers from Pu'er city, occupies 216.5 square kilometers. It consists of a national forest park, a provincial nature reserve and a forest. The 70-square-kilometer nature reserve has 812 kinds of wild species, among which 57 are protected.

Cang Wei in Nanjing contributed to this story.