Wetlands on the middle and lower Yangtze River floodplain are of vital importance to many species of waterfowl, the summary of a recent survey confirmed. It also disclosed that different water levels in the region had changed waterbird distribution considerably this spring.

The survey, the second comprehensive, simultaneous count of waterfowl along the floodplain of the middle and lower reaches of the Yangtze River, was organized by the State Forestry Bureau and China Program Office of the World Wide Fund for Nature (WWF). The first count was carried out in February 2004.

From February 15 to 28 this year, 12 survey teams visited most of the wetlands scattered around the provinces of Hubei, Hunan, Jiangxi, Anhui and Jiangsu and Shanghai Municipality to conduct the count. Teams comprised over 60 experts and volunteers from nature reserves, provincial and county forestry bureaux, colleges and conservation NGOs.

Last week the WWF published the conclusions of the survey. It reveals that over 630,000 waterbirds wintered on the middle and lower Yangtze River floodplain this spring.

According to the summary, 635,967 waterbirds of 95 species were counted during the survey, an increase on the 515,896 from 83 species recorded in 2004.

Of those, 226,175 birds were counted in Jiangxi Province - the area found to have the largest distribution in terms of waterfowl numbers. The place with the lowest, numbering 20,018 birds, was Shanghai.

Fourteen globally-threatened species and one under threat were found during the survey, according to the report.

Of these, the count of Swan Geese (61,178 individuals) exceeded the current estimate of the global population (55,000).

The number of Lesser White-fronted Geese amounted to 8,636, representing 62 per cent of the estimated flyway population.

Large numbers of cranes were spotted. Ninety per cent of the global population of Siberian Crane, 2,693 individuals, were counted and 37 per cent of the regional population of the White-naped Crane, 1,491 individuals. The number of Hooded Cranes, 1,088, exceeded the estimated flyway population - 1,000.

Forty percent of the global population of the Oriental White Stork, 1,194 individuals, were counted.

Other globally-threatened species seen in smaller numbers were the Black Stork (61), Scaly-sided Merganser (44), Saunders's Gull (34), Baer's Pochard (8), Black-faced Spoonbill (4), Swinhoe's Rail (2), Relict Gull (2) and Dalmatian Pelican (1).

In addition, 123 individuals of the under-threat Ferruginous duck were counted.

According to the report, the most common waterbird recorded was the Bean Goose with over 100,000 sited during the survey. Other species counted in large numbers were the Tundra Swan, 65,114, Swan Goose, 61,178, Common Teal, 43,037, Dunlin, 41,744, Spot-billed Duck, 29,210, Greater White-fronted Goose, 26,494, Common Black-headed Gull,22,616, Pied Avocet, 20,636, Black-crowned Night-Heron, 16,934, Falcated Duck, 14,763, Mallard, 13,884 and Common Coot, 12,414.

The number of Eurasian Spoonbill, 6,853, exceeded the estimated flyway population of 6,500. Species present in large percentages of their estimated flyway populations were: Bean Goose (91 percent), Tundra Swan (77 percent), Black Stork (61 percent), Falcated Duck (42 percent), Pied Avocet (21 percent) and Greater White-fronted Goose (20 percent).

The most common species groups were ducks, geese and swans, comprising 67 percent of the waterbirds counted. Next came shorebirds at 16 percent, egrets and herons at 5 percent, and gulls at 4 percent.

In comparison to the 2004 count, 120,000 more waterfowl were counted in 2005, and an additional 12 species (95 compared to 83) were identified. But this increase was mainly due to extended coverage of the survey in Jiangxi, Hubei and Shanghai, the report pointed out.

Heavy rainfall in the middle and lower Yangtze River floodplains raised water levels in the spring, affecting the distribution of waterfowl, according to the report.

It also revealed that increasing human activity around the wetlands, especially fishing, had greatly disturbed waterbird behavior and caused serious deterioration of water quality and the wetland ecosystem.

In order to analyze the changing trends and reasons for waterbird distribution, consecutive data collection is needed. As a result, sources with the China Program Office of the WWF said that it would cooperate with government bodies to continue the survey in 2006 so as to develop a statistical monitoring mechanism in the future.

(China Daily April 14, 2005)