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.

Seasonal abundance and potential of Japanese encephalitis virus infection in mosquitoes at the nesting colony of ardeid birds,Thailand

Objective:To investigate the abundance and seasonal dynamics of mosquitoes,and to detect Japanese encephalitis virus(JEV)in these mosquitoes at the nesting colony of ardeid birds.Methods:Mosquitoes were collected bimonthly from July 2009 to May 2010 by Centers for Disease Control.Light traps and dry ice,as a source of CO_2,were employed to attract mosquitoes.Mosquitoes were first identified,pooled into groups of upto 50 mosquitoes by species,and tested for JEV infection by viral isolation and reverse transcriptase polymerase chain reaction.Results:A total of 20370 mosquitoes comprising 14 species in five genera were collected.The five most abundant mosquito species collected were Culex tritaeniorhynchus(95.46%),Culex vishnui(2.68%),Culex gelidus(0.72%),Anopheles peditaeniatus(0.58%)and Culex quinquefasciatus(0.22%).Mosquito peak densities were observed in July.All of 416 mosquito pools were negative for JEV.Conclusions:This study provides new information about mosquito species and status of JEV infection in mosquitoes in Thailand.Further study should be done to continue a close survey for the presence of this virus in the ardeid birds.