Study On The Migration Of Black Kite Tracked By Satellite

The Black Kite(Milvus migrates)is a national level II key protected wild animal,and the IUCN species is no danger(LC)species,which belongs to the hawk family(Accipitridae)of the eagle order(Accipitriformes).In recent years,due to poaching and legal trade and habitat degradation,the survival of Black Kites is facing serious threats.At present,the migration studies of Black Kites are mostly focused on European populations,but there is no report on the migration studies of Black Kites in China.In this study,a new satellite tracking technique was used to track the Black Kite in China,in order to provide scientific data for the protection and habitat research of Black Kites.On September 25,2018,two Black Kites were rescued and released for the rescue center of Baoding City,Hebei Province.Two Black Kites were equipped with satellite trackers(No.YYDZ014 and YYDZ010).The migration route,stopover places,migration speed,migration height and daily migration distance of Black Kites were obtained by sorting and analyzing the data of satellite trackers.At the same time,the migration data and meteorological factors(weather,wind direction,wind force,temperature)were combined to understand the impact of meteorological factors on the migration of Black Kites,and the activity habitat,activity area and activity rule of Black Kites were analyzed according to the data of Black Kites in breeding place and overwintering place.The main results were as follows:1 Migration routes and stopoversThe overwintering places of Black Kites were Southeast Asia:Myanmar and Thailand respectively,and the breeding area was Hulunbuir city of Inner Mongolia Autonomous Region.The migration mode of Black Kites was narrow migration,mainly along the Northeast-Southwest mountains such as Daxing'an Mountain,Taihang Mountain,Wushan Mountain and Dalou Mountain.There were two kinds of stopover places in the process of migration:long-term stopover and night rest.The number of stopover places at night was very significantly higher than that of long-term stopover places(P<0.01).There was a extremely significant positive correlation between the long-term stopover in autumn and the weather(P<0.01),while there was a significant positive correlation between the long-term stopover in spring and the daily average temperature(P<0.05).In addition,the stopping frequency of Black Kites in forest area was very significantly higher than that in farmland,waterside forest land and grassland(P<0.01).2 Migration strategies(1)Black Kites mainly migrate during the day.The daily migration time of Black Kites in spring was significantly higher than that in autumn(P<0.05).During spring and autumn migration,the daily pause time of Black Kites was very significantly higher than the daily migration time(P<0.01).(2)The average migration speed and daily migration distance of Black Kites in spring were significantly higher than that in autumn(P<0.05),The average migration height in spring was higher than that in autumn,but the difference was not significant(P>0.05).In addition,there was no significant discrepancy in the average migration speed and average daily migration distance between spring and autumn migration stages(P>0.05).(3)There was no significant difference in the average migration speed,average migration height and average daily migration distance between the autumn migration after the rescued and released of Black Kites and the autumn migration in the natural state of the second year(P>0.05).(4)There was an extremely significant positive correlation with the weather and wind direction(P<0.01)and a significant negative correlation with wind speed(P<0.05)in autumn migration.However,there was no significant correlation between the migration distance and velocity of Black Kites in spring and the weather,wind direction and wind force(P>0.05).In addition,during the migration in spring and autumn,there was a significant negative correlation between migration height and latitude(P<0.01),and there was a significant positive correlation between migration height and weather(P<0.05).(5)In autumn,Black Kites prefers to migration in good weather?downwind?breeze?1-2 levels of wind,and the distance was the farthest;In spring,Black Kites will move under adverse weather conditions.3 HabitatThe overwintering and breeding grounds of Black Kites were near the wetland.The overwintering area was divided into three regions and four periods.There were fixed night rest areas in each period,and the active areas of each period were 108.48±64.35 km~2?87.50±51.75 km~2?69.48±36.93 km~2 and 12.45±11.45 km~2 respectively.Moreover,the daily activity range of early stage was very significantly higher than that of other periods(P<0.01);the activity amount of early stage was significantly higher than that of other periods(P<0.05);the active area of early stage was larger than that of other periods,but the difference was not significant(P>0.05).The breeding ground was divided into two areas and two periods,and the active areas of each period were 20.67±30.60 km~2 and 210.67±244.79 km~2.There was a fixed night resting place in the early bleeding stage.The daily activity time was 4:00-21:00,the activity amount was largest at 10:00 and 16:00.In addition,the regional habitats of the early activities were waterside,grassland and forest.There was a very significant discrepancy in the time distribution between waterside and grassland(P<0.01),and there was a significant difference in time allocation between forest and grasslands(P<0.05),but there was no significant difference in time allocation between waterside and forest(P>0.05).There was no fixed night rest place in the later bleeding period,which the straight line distance of the two night rest places was 0.17-27.39km.The activity area and daily range of activities in the later period were higher than the early period,but the difference was not significant(P>0.05),while the amount of activity in the later period was very significantly higher than the early period(P<0.01).