Foraging guild structure and niche characteristics of wintering waterbirds at Lake Shengjin, lower reaches of the Yangtze River

Abstract

集团结构和生态位特征是量化动物群落组织过程的重要指标，鸟类集团结构及其食物资源分割的分析对于理解群落中不同鸟种生态适应性具有重要意义.越冬水鸟集团结构和生态位特征取决于食物资源的丰富度和可获得性.本文通过对升金湖越冬水鸟的觅食生境和觅食行为的观察，对水鸟群落的集团结构进行划分，采用Levins指数和Pianka指数计算生态位宽度和生态位重叠度.结果表明，升金湖越冬水鸟可被划分为4个觅食集团，即G1浅水啄食集团、G2草滩啄食集团、G3广食性集团和G4深水潜水觅食集团.在浅水和中水区的觅食集团物种组成比深水区的水鸟集团丰富.G3广食性集团的生态位宽度远高于其余3个特化集团.比较而言，所有水鸟物种的觅食行为均较特化，但在觅食生境方面却较宽化.同一集团内物种间的生态位重叠远高于集团间的生态位重叠.G3广食性集团内物种的生态位重叠度低于其它特化集团内物种的生态位重叠度.研究结果表明，升金湖越冬水鸟群落集团结构主要受食物资源空间配置及其可利用性的影响.水鸟群落结构和生态位特征的信息对监测升金湖湿地的质量和制定有效的湿地保护策略都具有重要意义.;Guild structure and niche characteristics are important indicators to quantify the assemble process of animal community. It is of great significance to analysis bird guild structure and food resource partitioning for understanding ecological adaptability of different bird species in a community. The guild structure and niche characteristics of wintering waterbirds depend on the abundance and availability of food resources. In this study we divided the guild structure of waterbird community based on the data of foraging habitat and foraging behavior of wintering waterbirds collected at Lake Shengjin, and calculated the niche width and niche overlap using Levin's index and Pianka index. The results showed that the waterbirds at Lake Shengjin can be divided into four different foraging guilds, namely the G1, pickers in shallow-water, G2, pickers in grassland, G3, generalists and G4, divers. The species composition of foraging guilds in shallow and middle-depth water is richer than that in deep water. The niche width of G3 generalists is much higher than that of the other three specialized species guilds. In comparison, the foraging behavior of all waterbird species is more specialized, but the foraging habitat is more generalized. The niche intra-guild overlap of waterbird species is much higher than that of inter-guilds. The niche overlap of species in G3 generalist is lower than that in other specialized guilds. The results show that the guild structure of wintering waterbird community at Lake Shengjin mainly affected by the spatial allocation and availability of food resources. The information of water bird community structure and niche characteristics is of great significance for monitoring the quality of Lake Shengjin wetland and developing effective wetland protection strategies.