Activity Characteristics And The Habitat Suitability Of Oriental White Stork(Ciconia Boyciana)

Climate change and anthropogenic activity are two major contributors to recent wetland loss and degradation,further threatening the population of endangered waterbirds.The oriental white stork(Ciconia boyciana)is a typical endangered species in wetlands.It is necessary to identify its activity characteristics,migration routes,stopover sites and,distribution of potential habitat under different climate scenarios for restoring population and comprehensively planning the protection strategies of the oriental white stork.This study tracked 4 oriental white stork fledglings using satellite in the Sanjiang Plain in July 2016.Based on satellite tracking data,the activity rhythm and spatial movement patterns of the oriental white stork fledglings before leaving nests were analyzed.After the oriental white stork fledglings leaving the nests,the area and land cover in important activity zones were determined,the migration routes and stopover sites were verified.The distribution of current and future habitat suitability was analyzed by software Max Ent under four climate change scenarios of 2041-2060.Based on model results,we quantified the importance of environmental predictors on habitat suitability.This study provides systematic recommendations for the future conservation of oriental white stork.The main conclusions are as follows:(1)The oriental white stork fledglings were more active during the daytime,with significant activity peaks occurring around sunrise(3:00-6:00 A.M.)and sunset(17:00-19:00 P.M.).The high peaks and low peaks of daytime activities appeared alternately,while the intensity of night activities was lower.Fledglings tended to concentrate their movements around two or three hot-spot locations which were flat spaces or small ponds.The area of home range varied considerably among the four individuals,ranging from 14.79 to 39.40 km~2(100%MCP)and 5.56 to 16.01 km~2(95%FKD).The core home range of fledglings ranged from 0.01 to 3.46 km~2(50%FKD).The movement range of oriental white stork fledglings in the early chick-rearing period was small,while it increased in the late chick-rearing period.The area of home range in late chick-rearing period is 12-49 times larger than early chick-rearing period.(2)There were 10 important activity zones distributing near rivers and lakes after the fledglings leaving nests.The stopover time of the oriental white stork fledglings in the activity zones ranged from 8-45 days.The mean activity zone areas of four oriental white storks were 468.92±167.07 km~2(100%MCP)and 379.89±119.68 km~2(95%FKD),and the mean area of the core activity zones was 63.19±13.76 km~2(50%FKD).The main types of land use inside the activity zones were paddy(43.39%),swamp(29.78%),dryland(12.35%),and water body(7.3%).(3)More than 40%of the satellite tracking sites for oriental white stork fledglings clustered in the swarm,and the percentage was higher in water body,paddy,and dryland.The distributions of oriental white stork were generally far from roads,villages,and buildings.In this study,we obtain two full migration routes of oriental white stork fledglings(Bird ID:NIG022,NIG023),Heilongjiang to Poyang Lake route,and Heilongjiang to Bohai Bay route.The Heilongjiang-Poyang Lake migratory fledgling migrated from the Sanjiang Plain in the autumn and traveled across the Bohai Bay to Poyang Lake for overwintering.The migration time in autumn was 50days,and the migration distance was 3276.34 km,with 4 stopovers during the migration.The migration in spring started from Poyang Lake,flew accross Bohai Bay,and arrived along the Heilongjiang.The migration duration in spring was 12 days,and the migration distance was 2795.83 km,with one stopover site during migration.The Heilongjiang-Bohai Bay migratory fledgling migrated from the Sanjiang Plain to the Bohai Bay for overwintering.The migration time in autumn is 39 days,the migration distance is 2057.19 km,and there are two stopover sites during migration;the migration in spring started from the Bohai Bay to the Heilongjiang.The duration was48 days,the migration distance was 2653.11 km,with 2 stopover sites.The mean area of stopover sites was 155.60±217.55 km~2(100%MCP)and 253.47±243.20 km~2(95%FKD).The core area of stopover sites was 44.37±36.30 km~2.The stopover sites near Bohai Bay had larger area than others.The main land use types inside stopover sites were swamp(45.00%),paddy(21.26%),unused land(17.47%),and water body(9.59%).(4)The predicted current suitable habitats(including highly suitable areas,moderately suitable areas,and marginally suitable areas)during the breeding period mainly distributed in northeast and southeast of Sanjiang Plain.The total proportion of suitable habitats was 19.98%(2.18×10~4 km~2).In 2041-2060,the suitable habitats expanded under SSP126 and SSP245 climate scenarios,increasing by 201.33%(4.38×10~4 km~2)and 275.81%(5.99×10~4 km~2)respectively.Under the SSP370 and SSP585 climate scenarios,the area of suitable habitats decreased by 44.12%(1.03×10~4 km~2)and 86.95%(1.89×10~4 km~2)The distribution of suitable habitats during the breeding period moved to higher latitudes in 2041-2060.(5)The predicted current suitable habitats during the wintering period were mainly around Poyang Lake,the costal of Bohai Bay,Yellow Sea,East China Sea,and South China Sea.The proportion of suitable habitats was about 3.33%(2.40×10~4km~2).Compared with the current habitat suitability classes,the area of suitable habitat under all climate scenarios in 2041-2060,the suitable habitat contracted.The suitable habitat decreased by 86.61%(SSP126)?44.30%(SSP245)?62.37%(SSP370),and56.42%(SSP585).The suitable habitats of the oriental white stork during the wintering period showed an overall shrinking trend from 2041-2060.