Shanghai Daily News

Chongming is China's third biggest island after Taiwan and Hainan, but the rural county is also home to Shanghai's largest wildlife sanctuary.

The Shanghai Chongming Dongtan National Natural Reserve is a sea of green that is home to numerous animals, including that of the flying, swimming and land variety, in an area simply known as Dongtan Wetland.

The island, formed by the mud and sand silt where the Yangtze River and East China Sea collide, is growing by about 80 to 110 meters annually as it stretches into the sea. It is estimated to have an area of 326 square kilometers, of which 241.55 square kilometers belong to the nature reserve.

At present, a total of 265 species of birds have been observed at the wetland, 34 of which are protected by the Chinese government.

In early November, shorebirds touched down and then departed on their migration to Australia. As more wild geese, ducks and other birds spend the entire winter here, their numbers peak late this month and in January. With the increased population, now is the season for bird watching in Chongming. Visitors to Dongtan National Bird Natural Reserve, those of the human variety, need to apply for a permit at the management office at the site for entry.

This week, District Special looks at some of the inhabitants living temporarily in Chongming County.

Shorebirds

The East Asian-Australian migratory shorebird flyway is one of eight major bird migration routes in the world. The Dongtan Wetland is the birds' first station when heading north and their last stop when flying back to Australia.

Their migration season in East Asia is March to May. They then fly back home starting in August to enjoy the southern hemisphere's summer in Australia and New Zealand starting this month. The shorebirds have a hard journey in spring when they struggle to reach Western Siberia early to get a good nesting spot.

When flying home to the southern hemisphere, the birds have already bred and their journey takes them about 90 days, twice as long as the flight north.

After the first 5,000 kilometers of their trip to Dongtan, the birds are in need of food and refreshment to restore their weight, up to 60 percent of which has been lost during 15 days of non-stop flying. They live on grass seed, shells, snails and the tiny crabs found in Dongtan's pools, reeds and shallows.

Threatened species

Since the fall season, the Dongtan Wetland management has documented about 10,000 birds. It is estimated about 60,000 birds will make the site their temporary home through March.

Nationally-protected birds here include tundra swans, hooded cranes and black-faced spoonbills, among others. Each winter, more than 100 hooded cranes fly to Dongtan and stay until late March.

In November, a black stork was spotted there for only the second time since 1998, the year the reserve was established. The animal is an endangered species whose numbers are estimated to be no more 1,000 worldwide. The last record of black storks appearing in Chongming was in 1929.

Banding of birds

There are more than 9,000 species of birds on earth and more than a third are migratory - they migrate for the sole purpose of food and reproduction. Each year, the birds fly thousands of kilometers between the northern and southern hemispheres to get away from winter conditions. Islands and coastal beaches are their prime choice for midway resting places.

To chart their migration, some birds are tagged with a metal ring on their leg, a universally-accepted method for studying flight patterns and activity.

Starting from 2002, the Dongtan reserve set up a database for each banded bird, sharing the information with the National Bird Banding Center of China and similar organizations worldwide. The data can reveal valuable ecological analysis. This year, the reserve tagged more than 7,000 birds, the most among any other banding spot in the world.

Working with birds

Researcher Ma Qiang has worked at Dongtan Wetland since graduating from East China Normal University last year. While most of his classmates chose cellular and molecular biology, the 25-year-old Qinghai Province native chose zoology as he preferred to work in the wild with animals, instead of doing lab experiments.

Each 15 days, Ma and his Dongtan colleagues venture out into the wetland to carry out their observations. Calculating the number of birds can be a tough task as migratory birds move in large groups, there is no way to count them one after another. Researchers must identify a certain flying area first, and divide it into tens of smaller equal areas to get an approximate count.

Environmental protection

In the past 20 years, nearly half of the waterfowl species in Dongtan have seen their numbers reduced. This could be contributed to the fact that since 1987 the mud flat has dwindled by about 20 percent.

As waterfowl are essential to evaluating a wetland's quality, its biodiversity, which includes all forms of life, is drawing more and public awareness.

In 2002, the Dongtan Wetland joined the Convention on Wetland of International Importance Especially as Waterfowl Habitat - short for the Ramsar Convention - and was designated world Ramar Site 1144.

The reserve is now planning more activities to arouse public awareness on environmental protection. It intends to launch a student education area in the wetland by the end of May.

Address: Dongwang Road

Getting there: Take the ferry from Baoyang Port in Baoshan District to Baozhen Port. Ferries depart regularly. From Chongming, take the Chenhai Road eastward to Dongtan. There is no public bus so a taxi is the most common mode of transport.