Editor's note: As protection of the planet's flora, fauna and resources becomes increasingly important, China Daily is publishing a series of stories to illustrate the country's commitment to safeguarding the natural world.

A pair of patrolmen in Guangdong province's Nanling National Nature Reserve are going above and beyond the call of duty in their pursuit of surveying the local bird and butterfly populations.

Liu Zhifa and Wu Guoyi are both rangers in the reserve and both come from academic backgrounds, surpassing the requirements of your standard ranger.

After graduating from university, Liu and Wu forwent research positions to pursue their passions and a career getting their hands dirty.

To most patrolmen working in the country's nature reserves, their daily monitoring involves patrols along designated routes, taking note of any human activities that could threaten the environment and the wildlife, and uploading sightings of key species, typically those under State protection, onto their hand-held recording devices.

However, Liu and Wu have brought something to Nanling that few of China's reserves possess — the capacity to regularly conduct scientific surveys in specific areas of biodiversity conservation, such as birds and butterflies.

One of those surveys came in the form of the recent fourth Nanling Bird-watching Carnival, held from April 26 to 30 in Guangdong's Nanling National Nature Reserve and the bordering Mangshan National Nature Reserve in Hunan province.