扎龙湿地游禽类数量变动及原因分析

2006-2009年对扎龙湿地内的游禽类种群动态进行了研究,并将结果与1983年研究结果进行了比较.调查共记录到游禽鸟类3目3科24种,夏季游禽类繁殖鸟种类少、繁殖种群数量低,春秋季节迁徙鸟类种类多、数量高.在调查期间内游禽鸟类年际间的数量变动略呈下降趋势.1983年记录的37种游禽中有13种在本调查中未见.本研究6-...

Numerical Fluctuation of Waterfowls in Zhalong Wetland and Its Influence Factors

A survey was conducted on waterfowls(Anatidae),grebes(Podicipedidae) as well as coots and moorhens(Rallidae) from May to September during 2006-2009 in Zhalong wetland.The result was compared with that of the previous study in 1983.A total of 24 species were recorded,belonging to three orders and three families.The species composition and population size for swimming waterbirds fluctuated dramatically in Zhalong due to the low density of the breeding birds.The annual change in waterbird populations presented a slightly downward trend.Thirteen species previously recorded in Zhalong were not observed in the present survey.Compared with the previous study in 1983,populations for 13 species declined,among them seven species were not recorded in the present survey;those species that declined or were not recorded included especially breeding birds that have strong preferences for fresh water habitats.Populations of seven species increased,and those of 6 species remained stable.Ecological changes in Zhalong wetland in recent years,such as,drought,fragmentation of the wetlands,fires,hydrological disturbances associated with human activities,and habitat degradation,appear to be the causes of the population declines;therefore,effective measures on wetland restoration are needed.