Genetic Structure And Habitat Selection Of Dunlin (Calidris Alpine) Migratory Population In The Coast Of Rudong And Dongtai

Dunlin(Calidris alpina)is a small wader,and it is a circumpolar breeder in Arctic or subarctic regions.There are ten subspecies of dunlin and five lineages worldwide.Different subspecies would adopt different migratory strategies in the flyway,and they all select the intertidal flat in Rudong and Dongtai as staging site.During the fall migratory period in 2016 and 2017,the population genetic structure,habitat selection and the activity patterns of dunlin in Rudong and Dongtai were studied,with the morphological analysis,radio-telemetry tagging,environmental factors analysis,resighting and recovery data,and the phylogenetic analysis.The main results were as following:1.Combined recovery or resighting data,phylogenetic and morphological analysis,the result indicated that there are six subspecies staging in the coastal of Rudong and Dongtai during the autumn migration,which including C.a.actites,C.a.kistchinski,C.a.sakhalina,C.a.pacifica,C.a.hudsonia and C.a.arcticola.The individuals which breeding in Alaskan area formed the primary population in Jiangsu coastal wetland,and accounted for 47.32%of the whole population.The subspecies C.a.arcticola was common and accounted for 37.85%of the whole population.2.Six subspecies of dunlin mixed each other in Rudong and Dongtai coastal mudflat,and the migratory timetable of six subspecies was overlapped in that areas.The subspecies composition in 2015 was different from that in 2016.Individuals from Alaskan region held the higher proportion of population in 2015 than these in 2016.The result suggested that dunlin from Alaskan area would arrive at Rudong and Dongtai early during the fall migration,compared to these subspecies from the Far Eastern Russia.3.Dunlin had a habitat preference when they stay in Rudong and Dongtai.The intertidal area outside seawall was mainly regared as foraging area,and the artificial habitat was mainly regarded as high-tide roosting habitat when the tide was full.The culture pond had an eco-compensatory effect on the replenishment of dunlin at stopover.4.The unflooded area,distance from foraging region,soil humidity and the threaten have a key influence on the selection of the high-tidal habitat.Dunlin was preferred to roost at these habitats which are closing to foraging region,having a big unflooded area and wet.5.Dunlin adopted the headwind flight while the tide is rising or falling.The foraging behavior of dunlin between natural tide and artificial fishing pond were different.In the intertidal habitat,dunlin fed in visual pecking way and had a high foraging success.Whereas,dunlin fed in tactile probing way and had a low foraging success in culture pond.The composition of food in different habitats is the principle reason for the difference of foraging behavior of dunlin.