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.