Breeding Biology of Night Heron (Nycticorax nyticorax) and Little Egret (Egretta garzetta) in Taihu Lake of Wuxi,China

This paper describes the breeding biology of Little Egret and Night Heron in Yuantouzhu of Taihu Lake.In the research area,the dominant vegetations are Pinus massoniana and Cinnamomum hupehanum,which are suitable for herons to make their nests.The results showed that there were totally ten thousand nests,the nest density was about 0.36 m-2 and the number of nests per tree in average was 1.06.The average clutch size was 3.55 for Night Heron and 4.89 for Little Egret.The average brood size was 2.68 for Night Heron and 3.96 for Little Egret.Incubating time for Little Egret ranged from 19 to 21 days and for Night Heron was from 22 to 23 days.Hatching success was 84.25% for Little Egret and 75.46% for Night Heron.Nestlings of Little Egret fed mainly on small fish and shrimps,nestlings of Night Heron fed mainly on fish and amphibians.