Community composition and avian diversity in Nutan section of Qianjiang River in Guangxi

ObjectiveThe purpose of this study was to survey the composition characteristics of avian community structure and its diversity variation characteristics in different habitats and seasons in Nutan section of Qianjiang River in Guangxi,and provide reference for subsequent research on avian community in Guangxi river ecosystem.MethodThe fieldwork was conducted from March,2015 to February,2016,and divided into 4 seasons:spring,summer,autumn, and winter.The species,number,spatial distribution,and activities of birds in different seasons were investigated in the fixed transect and sample sites.The richness,dominance,species diversity and evenness index of birds in different habi-tats were calculated based on the information of birds,species and habitats.ResultThrough field investigation,37 spe-cies were recorded in Nutan section of Qianjiang River in Guangxi,which belonged to 22 families and 9 orders.Among them,24 species were resident birds(accounted for 64.9%),8 winter migrants(accounted for 21.6%),2 summer migrants (accounted for 5.4%),and 3 passage migrants(accounted for 8.1%). The dominant species(frequency index RB>10) were common sandpiper(Actitis hypoleucos),red-rumped swallow(Cecropis daurica),white wagtail(Motacilla alba), Richard's pipit(Anthus richardi),red-whiskered bulbul(Pycnonotus jocosus),light-vented bulbul(Pycnonotus sinensis) and eurasian tree sparrow(Passer montanus).The rest were common species or rare species.Among the five habitats,avian diversity index(H')and evenness index(E)presented the following features:woodland habitat>farmland habitat>wash-land habitat>riverside habitat>river surface habitat.The bird similarity indexes of woodland and farmland habitats were the highest,which were both 0.68.The seasonal variations of bird species and quantity in the study area were obvious.In woodland,the species of birds was the largest in winter(35 species),the least(26 species)in summer;and in farmland, the species of birds was the largest in spring(4394 species),and the least in summer(2334 species).ConclusionIn Nu-tan section of Qianjiang River in Guangxi,the proportion of forest birds is more than that of water birds.The seasonal variation of bird diversity is obvious,with the lowest species and number of birds in summer. The construction of the Datengxia water control project will pose great influence on water birds with strong dependence on rivers and wetlands in Nutan section of Qianjiang River,but it will not affect forest birds that adapt to farmland and woodland.The reservoir habitat will be difficult to attract water birds to rest and forage.