Migration Behaviors Of Reintroducted Pere David's Deer(Elaphurus Davidianus) In Dongting Lake District Based On GPS Technology

Movement refers to the process in which individual animals change their spatial position in a certain period of time,the purpose of which is to make animals move to a more suitable place in space.Movement is an important parameter for the study of animal behavior,which is the basic content of animal ecology.However,at present,the researches on the behavior of Milu(Elaphurus davidianus)mainly focus on the type and time distribution of behavior activities,and the research on movement has not been reported.On March 3,2016,in order to reduce the population degradation caused by inbreeding of Milu population,16 Milu individuals were introduced into the East Dongting Lake National Nature Reserve in Hunan Province from Dafeng Milu National Nature Reserve in Jiangsu Province.Eleven of them were equipped with GPS satellite trackers,which provided a rare observation opportunity to study the movement of Milu released in the wild.This study mainly uses GPS satellite tracking method and ground observation method to observe and analyze the movement behavior and adaptability of Milu released in the field from March 3,2016 to July 13,2018,and to explore the movement behavior of milu deer and the influence of several ecological factors.The main results of this study are as follows:(1)The movement activity curve of Milu in spring and summer showed obvious bimodal pattern.Among the two peaks,19:00-20:00 was the highest(the mean displacement distance was 209.70 m,the same as below.),followed by 6:00-7:00(173.25 m),and the two valleys were obvious at 4:00-5:00(93.07 m)and 23:00-0:00(91.83 m).Overall,the movement distance of Milu at night is longer than that of day,and with the passage of time from spring to summer,the diurnal movement behavior decreased gradually,and the nocturnal migration behavior increased significantly.(2)The long-distance movement mainly took place 10 months after the release of the wild Milu population,and gradually joined with natural wilderness Milu which was escaped from the enclosure of the Shishou Milu National Nature Reserve in Hubei Province in 2008,and eventually formed community in the Dongting Lake area.(3)Female Milu herds preferred to move over large distances(the daily displacement means was 1262.89m).Female Milu individual tended to wander in small areas around their habitats(the daily displacement means was 280.15 m),while the movement behavior of male Milu was relatively less affected by the aggregation(the daily displacement means was 808.05 m).(4)The first two months after the release of Milu in the field had an obvious adaptation period.The stress response of the first two days after release was obvious.The accumulated daily displacement on the first day could reach 8156.12 m,more than twice the normal value.After two months of adapting to the new environment,the movement activities gradually stabilized and accompanied by clustering.Later movement activities were more frequent until they were mixed with wild Milu.(5)Milu preferred to move in the temperature range of 11-22 0C.The move activity was less when the temperature is too high or too low,but it would rise slightly when the minimum temperature was below 5? in winter.The move distance of Milu was positively correlated with the elevation,especially in summer,and the influence of water level was higher in summer and autumn.There was a certain correlation with the elevation change of Milu reflecting that with the increase of water level,the Milu migrated to higher places.(6)The movement behavior of Milu was significantly different between Junshan Dadi and Houhu wetland(P=0.001)and Hongqi Lake wetland(P=0.024<0.05)in spring,and Houhu wetland in autumn(the progressive saliency is 0.000<0.01).The daily movement distance in Junshan Dadi area was far less than that in the other three wetland areas,which indicated that human disturbance factors have greater interference on the movement behavior of Milu.This study is helpful to understand the adaptation mechanism of Milu population released in the field,so as to promote the long-term self-maintenance and in-situ protection of Milu released in the field for our country.It provides important theoretical value and practical reference for the wild release of other endangered species under high intensity human disturbance in China.