浙江舟山五峙山列岛夏季繁殖水鸟资源及其分布动态

1989～2007年,对浙江舟山五峙山列岛自然保护区繁殖水鸟进行调查和监测,记录繁殖水鸟的种类、数量、分布及其繁殖生态。在五峙山列岛繁殖的水鸟主要有黑尾鸥Larus crassirostris、黄嘴白鹭Egretta eulophotes、小白鹭E.garzetta、中白鹭Mesophoyx intermedia、大凤头燕鸥Sterna bergii、黑枕燕鸥S.sumatrana和蛎鹬Haematopus ostralegus等7种。自1988年保护区建立以来,尤其是近年来,五峙山列岛繁殖水鸟的种类和珍稀鸟类黄嘴白鹭的繁殖数量呈上升趋势,其中黄嘴白鹭和大凤头燕鸥大繁殖群的出现大大提高了保护区的保护价值,不同年份间鸟类总体数量保持相对稳定。五峙山列岛繁殖水鸟的资源和分布动态呈现两个值得关注的现象:一方面,由于繁殖资源限制,繁殖种类间存在竞争替换;另一方面,不同繁殖年间繁殖水鸟在不同岛屿的分布数量存在较大的波动。其内在的影响因素值得进一步探讨,这对有针对性地制订保护和管理对策,降低黄嘴白鹭的竞争压力,最大限度地提高保护区繁殖水鸟的多样性具有重要价值。

Dynamics of Breeding Waterbird Resource and Their Distributions in Wuzhishan Archipelago,Zhonshan

The species, abundance, distributions and breeding ecologies of breeding waterbirds were investigated during 1989 to 2007 in Wuzhishan Archipelago Nature Reserve, Zhoushan, Zhejiang Province. Larus crassirostris, Egretta eulophotes, E. garzetta, Mesophoyx intermedia, Sterna bergii, S. sumatrana and Haematopus ostralegus were the main breeding waterbirds in the Wuzhishan Archipelago. Since the nature reserve was founded in 1988, especially in recent years, the species richness of breeding waterbirds and abundance of endangered species, Chinese egret have significantly increased, while the total breeding waterbird abundance has remained relative stabilization. There were two patterns of dynamics of breeding waterbird resource, and their distributions in Wuzhishan Archipelago were worthy of further research: the composition replacement potentially caused by breeding resource competition, and the distribution turnover of breeding individuals among different islands. To work out the underlying process will be important to the conservation of the breeding waterbirds, especially the Chinese egret in this area.