Comparison of Wintering Behaviors among Three Wading Birds at Nanji Wetland National Nature Reserve, Poyang Lake
The behavior patterns of the three sympatric,commonly coexisting wading birds Siberian crane (Leucogeranus leucogeranus),Grey heron (Ardea cinerea) and Eurasian spoonbill (Platalea leucorodia) were comparatively studied at Nanji Wetland National Nature Reserve,Poyang Lake,Jiangxi province,from December 2014 to March 2015.The main behaviors of the Siberian crane were foraging (82.60±6.57)% and vigilance (10.38±3.93)%,whose foraging behavior was more frequent than those of the other two wading birds (Grey heron (81.05±7.42)%,Eurasian spoonbill (63.30±28.77)%).What made the differences were (1) the Siberian crane and Eurasian spoonbill needed to consume more energy than the Grey heron because they are walking while foraging and in a fair to make up for the energy consumption by the time consumption;(2) compared with flesh-eating species (Grey heron,Eurasian spoonbill),the plant-eating species (Siberian crane) needed more time to take for food to accumulate sufficient energy.The main behaviors of the Grey heron and Eurasian spoonbill were resting and foraging,but the extremely significant differences found between this two birds were,the Eurasian spoonbill's foraging percentage was higher than that of Grey heron,the Grey heron' s resting percentage ((81.05±7.42)%) was higher than that of Eurasian spoonbill ((63.30±28.77)%),which indicated that these species might balance the energy consumption and acquirement,and then took corresponding behavior strategy.The study showed that (1) the vigilance behavior of the Siberian crane had no significant rhythm,and the percentage of foraging was relatively higher in each period;(2) the foraging and resting of the Grey heron occurred with no rhythm,and its foraging was less frequent in each period;(3) the Eurasian spoonbill's foraging behavior peaked in the morning (seven to fifty-nine past seven) and evening (seventeen to),and the resting behavior peaked at thirteen-one to fourteen.This three wading birds' rhythm benefited their coexistence,somehow reduce inter-specific competition for food resources among the three wading birds.