Study on Spartial Niche of Seven Species of Colonial Breeding Egrets and Herons of Fangcheng,Guangxi Autonomous Region

A wildlife survey of the egrets and herons from March to August of 2002 in Fangcheng,Guangxi Autonomous Region showed that seven species of egrets and herons,large egret(Egretta alba),intermediate egret(Egretta intermedia),little egret(Egretta garzetta),Chinese egret (Egretta eulophotes),cattle egret(Bubulcus ibis),Chinese pond heron (Ardeda bacchus),black-crowed night heron(Nycticorax nycticorax) were breeding in Wanheshan Mountain.Chinese egret was uniform distribution while the other six species egrets and herons were clumped distribution.The colonial breeding egrets and herons in Wanheshan Mountain showed obvious horizontal distribution and vertical distribution.Large egret,intermediate egret,little egret,cattle egret and part of black-crowed night heron occupied the east and the south of the central region of Wanheshan Mountain.Chinese pond heron and Chinese egret merely built their nests on the border region.The north and the west of the mountain were almost occupied by black-crowed night heron.Large egret,black-crowed night heron and intermediate egret located their nests on the upper levels of nestling trees,and little egret,Chinese egret and cattle egret in the middle,while Chinese pond heron on the lower.Factors influencing the spatial distribution of the colonial breeding egrets and herons,and the interspecific relationship of the community are inquired into.