Preliminary Study On Wintering Ecology Of The Oriental White Stork (Ciconia Boyciana) And Two Anseriformes Birds In Poyang Lake

1. Population size and distribution, the behavior comparison of the coexisting wading birds, foraging strategy, coexisting waterbirds of the wintering Oriental white stork(Ciconia boyciana) was studied in the 34 lakes 4 nature reserves at Poyang Lake from December 2014 to March 2015. Results are as follows:(1) Most of the wintering Oriental white stork was distributed in Poyang Lake National Nature Reserve from Nov 2014 to Feb 2015. Partial wintering Oriental white stork was distributed in Nanji Wetland National Nature Reserve from Dec 2014 to Mar 2015. It indicated that these two national nature reserve were important for the Oriental white stork.(2) The Oriental white stork, Siberian crane(Leucogeranus Leucogeranus), Grey heron(Ardea cinerea) and Eurasian spoonbill(Platalea leucorodia) are the common coexisting wading birds at Poyang Lake. We compared the behavior patterns of the four sympatric wading birds at Nanji Wetland National Nature Reserve, Poyang Lake, from December 2014 to March 2015. The main behaviors of the Siberian crane were foraging. And the Siberian crane spent much more time in foraging than the other wading birds. The Oriental white stork,Siberian crane and the Eurasian spoonbill need consume more energy than the Grey heron because they walk when they are foraging. Compared with flesh-eating species(Oriental white stork, Grey heron, Eurasian spoonbill, the plant-eating species(Siberian crane) need spend too much time in taking the plant for food to accumulate enough energy.The Oriental white stork, Grey heron and Eurasian spoonbill's foraging rhythm are different; this rhythm could reduce the competition of food resource for them, and allow them to be sympatric.(3) Oriental white stork foraging habitats varied in different months and gradually shifted from shallow water to grassland. The oriental white stork mainly preyed on fish in shallow water, and it handled large-sized fishes(>15 cm) for 201.07±35.31 sec(n=23), and small-sized fishes(<15 cm) for 85.22 ± 20.86 sec(n=14).(4) A total of 46 coexisting waterbird species belonging to 13 families, 6 orders were recorded from Nov 2014 to Mar 2015. The Black stork(C. nigra), Siberian crane, Hooded crane(G. monacha) are listed in the first category of the nationally protected wildlife species.The Eurasian spoonbill, Tundra swan(Cygnus columbianus), White-fronted Goose(A.calbifron), Common crane(G. grus) and White-naped crane(G. vipis) are listed in the second category of the nationally protected wildlife species. Of 46 coexisting waterbirds, the Litter grebe Tachybaptus ruficollis, Grey heron(Ardea cinerea), Eurasian spoonbill, Swan goose,White-fronted goose, et al. were frequent coexisting with Oriental white stork.2. From December 2014 to March 2015, the behavior pattern and habitat use of the Swan goose and White-fronted goose were studied at Nanji Wetland National Nature Reserve,Poyang Lake, Jiangxi province to study how niche separation of these two anseriformes birds.Results are as follows:(1) The results showed that the main behaviors of the two geese were resting and foraging. The Swan goose spent more time in resting than the White-fronted goose, less time in foraging than the White-fronted goose. Foraging behavior of the Swan goose peaked at14:00–14:59 and resting peaked at 13:00–13:59. Foraging behavior of the White-fronted goose had the highest observation frequency at 8:00–8:59, 12:00–12:59 and 16:00–16:59, and resting behavior had the highest observation frequency at 10:00–10:59, 12:00–12:59 and16:00–16:59. The competition of food resource for Swan goose and White-fronted goose can be reduced through the differentiation of behavior, which allows them to be sympatric.(2) The Swan goose preferred usting the shallow water and mudflat, the White-fronted goose preferred using the grassland. However, these two birds both preferred selecting the habitat with the distance of > 400 m. The differentiation of habitat selection avoid the competition of the highly niche overlap in offshore distance, that made them gain the maximize fitness, reduced the interspecific competition and allowed them to be sympatric.