Study On Avian Diversity And Analysis Of Nest Site Characteristics Of Herons In Wuhu City

Urban avian diversity is an important part of city biodiversity, which plays an important role in ecological balance of cities. From March, 2004 to October, 2005, we studied four typical avian communities in habitats of village & farmland, urban woodlot, floodplain and riverine wetland in the urban and suburban area of Wuhu. A total of 138 species were recorded, which belong to 16 orders, 32 families. We analyzed each diversity index in summer and winter. During 2005, we also investigated nest site characteristics of little egrets, black-crowned night-herons and Chinese pond-herons by collecting samples from four heronries in Wuhu & vicinity. Eleven nest-site variables, i.e., nest tree species, nest height, height of nest tree, coverage above the nest, coverage 1m around the nest, diameter of nest tree at breast height, distance of nest from tree center, diameter of the nest branch, distance of nest to heronry edge, slope location, altitude were measured. Nest site characteristics among three species of herons have been analyzed and studied with the methods of one-way analysis of variance and principal component analysis. Results show that both the avian species and G-F index of the summer avian communities are higher than those of the winter communities in village & farmland, urban woodlot and floodplain; the species number, Shannon-Wiener index, Pielou index of the winter avian community are higher than those of the summer avian community in riverine wetland; both the avian species and G-F index of urban woodlot are greatest among the four habitats; Shannon-Wiener index and Pielou index of floodplain are higher than those of other three; in summer village & farmland has the highest density(31.1140 ind·hm^-2), while in winter urban woodlot has the highest density(42.9160 ind·hm^-2); the avian species, density, Shannon-Wiener index and G-F index of riverine wetland are all lower than those of the other three habitats. Four components describing sampled nest habitats are nest site, nest tree, protection and slope location, the contribution rate of them respectively is 25.508%,24.422%,13.192%,12.318%. Avian diversity can be enhanced by increasing spatial heterogeneity and reducing human disturbance.