The Habitate Use Of Migrant Shorebirds In Suaeda Salsa Salt Marshes And The Intertidal Flats In Liaohe River Delta

The Liaohe Estuary National Nature Reserve in Liaoning Province is an important international wetland,providing the breeding and wintering ground for many migratory birds.It is also an important stopover site for the migration of waterbirds and was much valuable in the conservation of shorebirds on the East Asia-Australasia Flyway.The study were conducted in the Liaohekou National Nature Reserve during the two migration periods from April to May in 2017 and October to November in 2018.The community composition,behavioral composition and feeding utilization of shorebirds in the Suaeda salsa salt marshes and adjacent intertidal mudflat were studied.In addition,the food composition and foraging behavior of two Suaeda salsa habitat dependent shorebird species(Far Eastern Curlew Numenius madagascariensis and European Curlew Numenius arquata)were also studied.The main results are as follows:1.A total of 35 species of Charadriiformes were counted in the study area,of which 24 species were recorded in the spring migration period(the Suaeda salsa salt marshes:17 species,intertidal tidal flats:18 species),and 30 species were recorded(the Suaeda salsa salt marshes: 21 species,intertidal tidal flats: 24 species)in autumn.There were no significant differences of species and numbers in the Suaeda salsa salt marshes and adjacent intertidal mudflat habitat in spring and autumn,except for the number in the autumn.The number of shorebirds in the intertidal flats was significant higher than that of the Suaeda salsa salt.The density of shorebirds in the intertidal tidal flats plots was higher than that of Suaeda salsa salt marshes during all the migration.2.There were significant difference habitat use of different shorebird guilds.The tactile continuous and Pause-travel guilds mainly used the intertidal tidal flats.The gulls shorebirds species highly used the intertidal tidal flats.There was no significant difference in habitats use for visual continuous shorebirds in the two habitats.3.The main behavior of Charadriiformes were foraging(44.90%)and resting(41.41%)in the Suaeda salsa salt marshes.But in the intertidal tidal flat,the main behavior was foraging(79.02%),with 16.31% of behavior belonging to the resting.The visual continuous,the Pause-travel and the gulls guilds were mainly foraging and resting in the Suaeda salsa salt marsh,and mainly foraging in the intertidal tidal flat;but the tactile continuous shorebirds was mainly foraging in the two habitats.4.The tidal crabs(63.02%)and ragworms(30.70%)were the main prey for the Numenius madagascariensis and Numenius arquata curlews through pellet identification and video recording of foraging behavior.There was significant higher foraging efficiency for crabs in the intertidal mudflat than in Suaeda salsa salt marsh,but not for the foraging of ragworms by the curlews.