The delta of the Yellow River, China's second-longest waterway, has become a paradise for various species of wild bird thanks to restoration of the environment.

At least 368 species of birds have been spotted in the delta, including red crowned crane, oriental white stork and Saunders' gull, ornithologist Wang Lidong told Xinhua.

Located on the Yellow River estuary at Dongying in east China's Shandong Province, a reserve covers 153,000 hectares. In 2000, only 283 species were recorded in the area, Wang added.

Wang attributed the increase to conservation work at the reserve in recent years. A rising number of fish, frogs and snakes provide food for birds, he said.

Oriental white storks have been seen on the estuary for 13 years. The storks used to nests on top of telegraph poles but some nestlings were burnt to death when the wires caught fire.

Reserve staff have set up 35 15-meter poles to provide safe alternatives for the storks. Since 2005, a total of 741 oriental white storks have been bred on the delta, roughly 25 percent of the entire world population. A staff of 40 at the reserve protect birds from poachers.

Eight artificial islands have been built in reed beds in the delta with 2,000 birds on each island, Wang said.

A more reliable water supply has played an important role in protecting the delta. The river came close to silting up completely in the 1990s, with about 100 dry days each year. The shortage of water resulted in groundwater recession and sea water encroachment, leaving the soil salinated and desertified.

The river is an important water source for people living around the delta. Industrial water and more than 90 percent domestic water in Dongying, where the river empties into the sea, depend on the river.

Water from the Xiaolangdi Reservoir on the middle reaches of the Yellow River has flown into the wetland since 2008. The operation has increased both surface water and groundwater in the area while reducing soil salinity. The Xiaolangdi project has also helped clear up sediment in the lower reaches of the river, carrying hundreds of million tonnes of silt into the sea.

The 5,464 kilometer Yellow River originates on the Qinghai-Tibet Plateau and winds its way through eight provinces and autonomous regions before it meets into the Bohai Sea in Shandong.