Population Size And Migration Strategy Of Wintering Eurasian Spoonbill (Platalea Leucorodia) In China

The Eurasian Spoonbill(Platalea leucorodia)includes 3 subspecies and 6 geographic populations,and its East Asian populations overwinter in China,Korea and Japan.There is very little research on the distribution,number and migration strategy of the Eurasian Spoonbill overwintering population in China.Based on telemetry and bird survey data,this article updated the distribution range of the wintering populations in the summer and wintering areas in China,and assessed the population numbers and trends.The migration strategy,habitat use and protection status of this species are clarified,and the main results are as follows:Based on satellite tracking data,two main groups of Eurasian Spoonbills overwintering in China are obtained: the Yangtze River overwintering group in China;and the coastal overwintering group in China.Previous studies have shown that Eurasian Spoonbills spend summer in Northeast China,Xinjiang,and northern Mongolia.This article adds central Mongolia and the Hetao Plain of the Yellow River Basin in China as summer sites.Previous studies have shown that the Eurasian Spoonbill wintering grounds are distributed in the middle and lower reaches of the Yangtze River,in the east(Shanghai),4 provinces in the southeast(Zhejiang,Fujian,Guangdong,and Guangxi),and the southcentral Yunnan Province in the southwest.This article finds that this species is concentrated in the coastal areas of Jiangsu Province and Shanghai in the east,and very few in the southeast.The distribution range of the southeast coast is reduced to the coastal areas of Zhejiang Province,Fujian,Guangdong and Hainan.The southwestern Yunnan Province lacks data and retains the original distribution area..There are different migration corridors for wintering groups on the Yangtze River and the coastal areas in China.Migration corridors for wintering groups along the coast of China: Individuals who spend summer in the Naoli River,Sanjiang Plain and Xingkai Lake in Heilongjiang Province stop in Ussuri Bay and Jianghua Bay in Russia,and live in the coastal areas of Yancheng,Jiangsu Province and Taihu Lake in Zhejiang Province.The wintering population of the Yangtze River in China includes two migratory corridors.The eastern migration corridor shows: individuals who spend the summer in Hulun Lake in Inner Mongolia,travel through the Yellow River Delta to Poyang Lake in the Yangtze River Basin for winter;the western migration corridor shows: in Ubusu,Mongolia Individuals who spend summer in the Uvs lake and the Hetao Plain of the Yellow River Basin travel through southern Mongolia and the Yellow River Basin in Inner Mongolia to winter in Dongting Lake,Poyang Lake and Shengjin Lake in the Yangtze River Basin.Based on the structure of the migration route and the distribution of overwintering,combined with the survey data of overwintering waterbirds,this article estimates the number of overwintering populations of this species in China for the first time.The average value for 2016-2020 is about 19,500.Among them,19,200 in the middle and lower reaches of the Yangtze River and 300 in coastal areas.Including the overwintering numbers of Japan(80)and South Korea(300),the current population of East Asia and Eurasian spoonbills is 20,000.Compared with the estimated value of East Asian population data(10,000)in 2012,it shows an upward trend.This is mainly related to the increase in the number of China..The vast majority of East Asian Spoonbill populations are distributed in the Yangtze River Basin of China.During 2004-2005,there were 6 sites in the Yangtze River Basin where the population reached 1%,namely Poyang Lake in Jiangxi Province,Caizi Lake and Shengjin Lake in Anhui Province,and Hubei Province.Provincial Net Lake,East Dongting Lake in Hunan Province.During 2016-2020,there were 16 sites in the Yangtze River Basin where the population reached 1%.Including Shijiu Lake in Jiangsu Province;Caizi Lake,Shengjin Lake,Fengsha Lake,Qili River,Huangpi Lake,Wuchang Lake in Anhui Province;Poyang Lake in Jiangxi Province;Shenhu Lake,Fuhe Lake,Luhu Lake,Wanghu Lake,Huanggai Lake,and Haikou Lake in Hubei Province;South Dongting Lake and East Dongting Lake in Hunan Province.It was found that with the increase in the number of white spoonbills in recent years,the wintering distribution in the Yangtze River has become more widespread,and more than 40% of the individuals live in Poyang Lake..The study on the migration strategy of the white spoonbill found that,except for one breeding in eastern Inner Mongolia,the other two groups showed that the migration time in autumn was significantly longer than that in spring.The Eurasian Spoonbill juvenile will change its summer and winter grounds in the second year,thus shortening the migration distance.In summer,the main habitat types used by Eurasian Spoonbills are water bodies,wetlands and grasslands around wetlands,but in wintering areas almost only water bodies are used.During the spring migration,all tracked individuals did not use the protected area.Individuals in eastern Inner Mongolia and Naoli River make better use of the protected area at other times of the annual life cycle(49-95%),but the annual use rate of protected areas in western Mongolia is very low(5-22%)..This article reveals for the first time the migration routes of the Eurasian Spoonbill populations wintering in China,including the relationship among summering,stopover and wintering area;the distribution of Chinese populations is updated,and population trends are evaluated;at the same time,it determined the habitat utilization type and protected status of the Eurasian Spoonbill group wintering in China,clarified the importance of the water body's habitat for the species in the entire annual life cycle,and provided important basic data for the conservation and management of the species.