Habitat Selection And Migration Strategy Of Tundra Swans(Cygnus Columbianus)in Dongting Lake And Poyang Lake

Cygnus columbianus is a long-distance migratory bird that migrates twice a year between its wintering and breeding habitats,stopping at different places several times during its migration.This research aims to protect the habitat and migration route of Tundra Swan.Firstly,based on the GPS satellite positioning data of Tundra Swan from 2014-2017,we use remote sensing information technology to obtain the habitat land use type,clarify the home range of Tundra Swan in the habitat,and explore the habitat selection preference of Tundra Swan in combination with the land use type.At the same time,the migration route of Tundra Swan was mapped,migration parameters were calculated,key stopover sites were identified,and the current status of protected area utilization along the migration route was analyzed.(1)Tundra Swan wintering grounds habitat types were divided into seven categories,including water,grass,mudflat,paddy field,artificial surface,forest and bare land.Despite the same months,large shifts in land use types still occurred between years in the Dongting Lake study area.2014-2016 saw the highest rate of mudflat shift,with 58.62%transformed into water,8.90%into grass,and only 13.48%retained.2016-2017 saw a higher rate of water shift,with only 51.98%were retained,23.80%were transformed into mudflats,followed by grass with 21.70%.Comparing the land use types in the study area of Poyang Lake in 2015 and 2016,it was found that the rate of mudflat transfer was higher in the same months,with 31.77%converted to grass,9.10%transformed to water,and the retention rate was 48.40%.The habitat types of breeding sites for Tundra Swan were relatively simple,with those in northern Russia divided into tundra,water,bare land and ice/snow,and those in the Dornogovi of Mongolia and China’s Inner Mongolia Autonomous Region divided into grass,water and bare land.(2)In 2014,the overwintering Tundra Swan in Dongting Lake were mainly distributed in Bai Lake,Qixing Lake and Dingzhi Dike,and the home area(95%)of different individuals varied greatly,with the largest being 295.05 km2 and the smallest only 7.00 km2.2015-2017,they were mainly distributed in Dingzhi Dike and Big and Small West Lake.During the wintering period of three successive years from 2015 to 2017,the home range area of DTL-07(Dongting Lake-07)Tundra Swan decreased year by year to 464.79 km2,127.94 km2 and 56.99 km2,respectively.In 2015 and 2016,the wintering Tundra Swan in Poyang Lake were mainly distributed in Shi Lake,Dongjiang Lake,Baisha Lake and Sanniwan area,and the home range was larger than the wintering Tundra Swan home range in Dongting Lake.The home range of summering Tundra Swan in breeding areas is smaller than that of wintering areas.(3)Water,grass and mudflats were the three habitat types most used by wintering Tundra Swan in Dongting Lake,part of the Tundra Swan have some preference for paddy field and artificial surface,and forest was the habitat type never used.The wintering Tundra Swan in Poyang Lake have a large home range and complex habitat use.However,water,grass and mudflats were still the main types,and part of the Tundra Swan have a strong preference for farmland habitat.The habitats within the home range of Tundra Swan breeding in northern Russia were mainly large tundra as well as water,with a small amount of bare land and ice/snow,and for Tundra Swan located in the Dornogovi of Mongolia and Inner Mongolia Autonomous Region,water was the main habitats within their home range.(4)The fall migration of Tundra Swan was shorter and faster than the spring migration.In Asia,the migration route was divided into three parts:western,central and eastern routes.Tundra Swan spend most of their flight stopping to replenish their energy,which is a minimal energy consumption strategy.The Yellow River wetlands in Baotou,Inner Mongolia,the Yellow River delta on the eastern coast,Huolin River Wetland,Jilin Province and the central Lena River wetlands in Russia were the main stopover sites.Although the t Tundra Swan made several stops on their migration,out of a total of 50 stopover sites,only two were within the protected areas,eight were around the protected areas,and most of the stopover sites were not in any protected areas.This study can provide scientific basis for Tundra Swan population conservation,habitat protection and restoration.At the same time,it can help to understand its migration ecological rules,and can provide factual reference for the identification of important stopover sites,the planning and management of protected areas,and the protection and construction of migration ecological corridors.