The breeding season for birds is in the spring. The nature reserve branch of the Dongying Public Security Bureau stood firm day and night to closely monitor the Yellow River Delta National Nature Reserve, and prevent and crack down on illegal acts related to wildlife and ecology, in order to ensure the safe and smooth hatching and reproduction of birds.

The nature reserve spans an area of 1,530 square kilometers and it boasts the world's best preserved and youngest wetland ecosystem in warm temperate zones. Two of the world's nine major migratory bird routes pass through the reserve, where more than 6 million wild birds feed, perch and breed.

The good environment has enriched biodiversity in the nature reserve. According to official statistics, the wetlands are now home to 1,630 wild animal species and 685 plant species.

Yang Huazhang, a policeman from the nature reserve branch of the Dongying Public Security Bureau, patrols the hinterlands of the reserve, observes the birds living in the area and studies their way of life. [Photo/Dazhong News]

Police officers release illegally hunted wild birds, enabling them to return to nature at the Dongying Yellow River Delta National Nature Reserve. [Photo/Dazhong News]

Police officers monitor the breeding of oriental white storks in the Yellow River Delta National Nature Reserve in Dongying via video surveillance equipment. [Photo/Dazhong News]

Policemen patrol the Yellow River Delta National Nature Reserve on amphibious terrain vehicles. [Photo/Dazhong News]

Policemen protect the vast reserve, which is home to 1,630 wild animal species and 685 plant species. [Photo/Dazhong News]