四种鹭类繁殖生态生物学研究

本文对夜鹭，白鹭，黄鹭白鹭，池鹭混群在同一巢区的繁殖，种间协高及雏鸟生长进行进行了观察研究，其中黄嘴白路豫南大别山类新纪录，在此繁殖亦为首次发现。几种路在巢位，食性，取食活动和习性方面都表现出其混居同一巢地繁殖的种间协调性，符合高期假说。比较４种鹭鸟雏鸟生长过程中各生长参数。其中池鹭虽个体最小，但体重和各部位生长却对较快。

BREEDING ECOLOGY AND BIOLOGY OF FOUR SPECIES OF EGRET AND HERON

rom 1988 to 1989, observations on the breeding ecology and biology of four species ofegret and heron(Nycticornx nyticorax ,Egretta garzetta,E. eulophotes,Ardeola bacchus)havebeen taken in the Dongzhai bird conservation ,Henan province. The results are as following:E.eulophotes is a new record in south Henan province, breeding in this region for thefirst time.The four species of egret and heron are breeding in harmony of nested seat,nurture andaction in the same area. Most of N. nyticorax use the old nests,these seates are advanta-geous. Only fewer of E. garzetta and E.eulophotes use the old nestes.A. bacchus build theirnew nestes each and most of their nestes seating on the edge of the nest area. The nestes ofthese species are simple,dash-shapped.The size of nestes are varied depending on the size ofthe branches. Generally,its size is 30-45 outside ,20-30 inside,8-35 in depth and 12-25cm in height.Feeding habit of young birds:N. nyticorax feeds mainly on frongs and auxiliarily on littleloaches.E.garzetta feeds mainly on loaches and auxiliarily on small wild fishes.A. bacchusfeeds mainly on loaches and auxiliarily on frogs.E. eulophotes feeds only on loaches.The young birds of E. garzetta need about twenty days to pretect themself from beingcatched by man and easily escaped form one branch to another branch of tree.N. nyticoraxand E. eulophotes need twenty-two days.A. bacchus needs fifteen days. The growth rate of A.bacchus and E. garzetta is higher than N. nyticorax and E.eulophotes.When young birds ofthese four species leave their nestes,the length of their wings are nearly the same as theadult.The major breeding damage of egret and heron are disgusting weather in this region.