射阳县林场鹭巢调查初报

射阳县林场属江苏盐城国家级珍禽自然保护区缓冲区范围。经调查，在29．33hm^2水杉林内，统计到牛背鹭、池鹭、夜鹭、中白鹭、白鹭5种鸟集群营巢数达11996．8个，高密度区域每株水杉营巢数为3个；巢位距地面高因树的高度而异，分别为90～100，110～125，130～140cm。外围优越的生态环境为其高密度集群营巢创造了有利条件。

Population Dynamics and Breeding Space Niche of Four Heron Species in Tanghai Wetlands

The population dynamics and breeding behaviors of Black-crowned Night Herons （ Nycticorax nycticorax ）, Egrets （Egtetta garzetta）, Chinese Pond Herons （Ardeola bacchus） and Great Egrets （Casmerodius albus） were observed in Tanghai Wetlands, Hebei Province from August 2004 to July 2005. Further, we studied the relationship of nest space distribution and directly calculated the nest density of vertical and horizontal levels, the niche overlapping index and the niche breadth. The results showed that there were two breeding areas, named Area Ⅰ and Area Ⅱ . The maximum population occurred in the period from April to September and was approximately 5800 individuals. Area Ⅰ was occupied earlier than Area Ⅱ by approximately half a month. In the breeding period, Black-crowned Night Herons were dominant in numbers and most occupied the upper nests of the core areas. Great Egrets also took the upper nests but they have the smallest population. Most Egrets took the middle nests of the edges of the area. Chinese Pond Herons, with a smaller population than the Egret, mostly nested in the edges, but some of them also took the lower nests of the core area. On the whole, the vertical niche of Egrets is the widest, the horizontal niche of Black-crowned Night Herons is the widest and the niche breadth of Chinese Pond Herons is the largest. The nest distribution pattern is the most similar between Chinese Pond Herons and Black-crowned Night Herons, and the niche overlapping index of Chinese Pond Herons and Egrets is the largest. Black-crowned Night Herons and Great Egrets control Egrets and Chinese Pond Herons in competition. Rich food and the optimal ecological environments lead to plenty of herons in the wetlands. In addition, it is a distinguishing feature of the four species that nests are built in poplar trees over 22 m tall.

Ardeid nesting colonies in central Guizhou,southwestern China

A survey of Ardeid nesting colonies in central Guizhou,southwestern China in May 2006,which covered about one-third of the area of this province,recorded a total of 1587 nests of five species,i.e.,Little Egret (Egretta garzetta),Cattle Egret (Bubulcus ibis),Chinese Pond Heron (Ardeola bacchus),Black-crowned Night Heron (Nycticorax nycticorax) and Grey Heron (Ardea cinerea) at 11 nesting colonies.The largest colonies were recorded at Fengyunyan and Yanfu resorts,the smallest one at Luobolin.The Little Egret was the dominant nesting species (49.7% of the total number of nests) and the Grey Heron was the least abundant (0.1%).All nesting colonies were located in the northern and central parts of Guizhou;no colonies were found in the Leigongshan area,the southern part of this province.The distribution of nesting colonies in central Guizhou appears to be affected by the relative composition of winter (wheat and vegetable) and summer (rice) crops during the breeding season (between late March and June).No colonies were found around farmlands with winter crops and most colonies were situated around rice paddies.The farmland use pattern is affected by rainfall.The summer crop is delayed if the rainy season starts late and the rainfall is light.Priority for conservation of the Ardeids in central Guizhou should be given to the larger colonies i.e.,Yanfu and Fengyunyan resorts.

Effect of colonial breeding of Chinese Egret(Egretta eulophotes) on the heavy metal accumulation in heronry soil

We measured the concentrations of heavy metal elements,i.e.,V,Cr,Mn,Ni,Cu,Zn,Cd,Se and Pb and the semi-metal element As in feces of Chinese Egret(Egretta eulophotes)on Caiyu Island in Zhangpu County,Fujian Province,China using inductively coupled plasma-mass spectrometry(ICP-MS) and compared the differences between the topsoil of their nesting and non-nesting areas before and after breeding.The results show that no Se and Cd was detected in any of the samples,including feces and soil,while heavy metal concentrations in the non-nesting soil were not significantly different before and after breeding(p > 0.05),but the differences in concentrations of Zn and Pb in the nesting soil were highly significant before and after breeding(p < 0.01).A comparison of the concentrations of the elements in the nesting and non-nesting soils also reveals that before breeding,the concentration of Zn in these two soils were significantly different(p < 0.01).After breeding,concentrations of Cu,Zn,As and Pb in the nesting and non-nesting soil were significantly different(p < 0.01) while V and Ni concentrations showed merely significant differences(p < 0.05).These findings indicate that the colonial breeding activities of E.eulophotes play an important role in the transfer of heavy metals between wetland and island eco-systems and that such activities may,over time,result in heavy metal contamination of the heronry soil on the island.