Abstract:

Up till now,a complete survey on wintering bird population or avian community state in the Poyang Lake is lacking.So,here we mainly aims to study the avian population dynamics and species diversity in this area,which can help to put forward a better advice on the wintering birds and their respective habitations conservation.From 2010 to 2012,the winter bird community structure was investigated carefully in the whole Poyang Lake.Based on the distribution characteristic of the most wintering bird in the Poyang Lake,both the ringlake walking directly counting process and sample line methods were used for the survey on wintering birds in all dished lakes.Moreover,we also went boating and used concentric circlesample method to investigate the water birds distributed in deeper water area of the Poyang Lake.On the other hand,we walked or went boating at speed from 1.5 to 2.0 km per hour to investigate all onshore wading birds such as the cranes,storks,gooses and sandpipers by naked eye and telescope.When counting birds,we only adopted the birds staying or flying from the both sides and from the front.Meanwhile,considering heterogeneous distribution of the most wading birds,the individuals were counted by the statistic laws including the quadrat investigation,lineintercept method and direct counting method.
Eightyeight bird species were totally found in the field,but there was no record for 29 species reported formerly.All these 117 species belonged to six orders including Podicipediformes,Pelecaniformes,Ciconiiformes,Anseriformes,Gruiformes,Charadriiformes and Coraciiformes.Seventyeight winter migrant bird species,the most group in all bird species,were recorded in this investigation.There were 6 dominant wintering species including Cygnus columbianus, Anser cygnoides, A.fabalis, A.albifrons, Anas crecca and Anas poecilorhyncha in the Poyang Lake.Their mean individuals per year were all more than 10 000 in the survey area.Cygnus columbianus had the highest population number among this species,which reached to 54 277±36 600 per year.Especially,most of individuals of Cygnus columbianus were found in the Xin River and its peripheral dished lakes in Yugan County of Jiangxi Province.
Our investigation on wintering bird also indicated that the most birds were found in the lakes including Banghu,Dahuchi,Shahu,Dashahu,Huangjinzui,Baishahu,Linchonghu,Nanhu and Zhuhu,which were just the most important habitats for winter migrants in the Poyang Lake that needed to be concerned carefully and conserved in the future for the conservationist.Finally,our research indicated that the difference of species diversity and individual quantity distribution in Poyang Lake wetland was mainly caused by the water level and food richness of dished lakes.Only water level declined gradually in the winter,the wintering birds can more effectively make use of the food from these lakes.