The wetlands at the Yellow River Delta National Nature Reserve. HU YOUWEN/FOR CHINA DAILY

Biodiversity enriched

Liu, from the monitoring center, said this good environment has enriched biodiversity, and according to the delta nature reserve, the wetlands are now home to 1,630 wild animal species and 685 plant species.

A line on the big screen at the monitoring center indicates changes in the number of birds living or stopping over in the delta. It also shows that the number of avian species in the delta has risen from 187 in 1992 to 371.

Liu said: "We observed flamingos in March, white pelicans last December and spoon-billed sandpipers this year. More than 10,000 Saunders's Gulls bred at the reserve this year."

In addition, many Oriental storks live at the nature reserve throughout the year.

Zhao, the monitoring worker, said: "Oriental storks, an endangered species, gave birth at the nature reserve for the first time in 2005. Last year, they gave birth to 324 nestlings, and 2,278 of these storks have been born at the reserve."

The 34-year-old can identify more than 170 species of birds, and she has a wealth of experience in caring for her charges, such as building homes for the birds and creating a friendly and suitable environment on land and water for different species.

"Oriental storks like building nests in tall arbor trees, but because we have few of these trees, we have built nests for the birds on poles standing 15 meters to 17 meters high," Zhao said.

To date, 115 nests have been built for Oriental storks, she added.

"The nests, which are shaped like bowls, are 1.2 meters in diameter at the base, 2.2 meters in diameter at the top, and 35 centimeters deep. Birds place branches and leaves inside the nests, making warm homes for themselves in these artificially built structures," she said.

Zhao is among 20 people working at the reserve who monitor the birds' conditions every day.

Coastal waters near the Yellow River Delta are also important for marine life in the Yellow Sea and Bohai Bay to spawn, winter, feed and migrate, according to the nature reserve.

More than 2,000 swans, 40 red-crowned cranes and thousands of wild geese, gray cranes and wild ducks are now arriving daily in the delta, according to the nature reserve.

Zhao said: "When we walk around this vast reserve, we are not alone, as the birds are everywhere－on lakes, in woods and across the sky. It will be a beautiful winter."

A mallard leads her ducklings on a walk through seagrass at the reserve. LIU YUELIANG/FOR CHINA DAILY