基于卫星定位跟踪数据解读白头鹤的性别、年龄、繁殖及领域回归

Interpretation of sex,age,breeding and territory retention of Hooded Crane based on satellite tracking data

2014-2021年,在中国东北、长江中下游以及蒙古国和俄罗斯,通过救助和野外捕捉共计为33只白头鹤(Grus monacha)安装了卫星定位跟踪器,同时佩戴了金属环和彩色塑料环。根据卫星定位信息,找到繁殖巢后,在其周边布设红外照相机。利用卫星跟踪6年以上的6只白头鹤个体以及在小兴安岭北部度夏、繁殖的7只白头鹤个体的定位跟踪数据,将5月15日零时位点为基准点,利用设置的位移-时间计算公式将定位坐标转为位移-时间曲线,使获得的定位数据图形化,结合野外行为观察,获得判别指标:繁殖地或度夏地夜间位移-时间曲线的平直度,反映了白头鹤夜栖点的位置变化;根据曲线平直度判断:曲线平直的是雌性,曲线呈锯齿状的是雄性;距离繁殖区较近、曲线变化幅度非常大的是亚成体,在繁殖区域、曲线近乎平直达1个月左右的是成鸟;根据平直曲线长度,确认是否繁殖成功及初始繁殖年龄;4月初至6月末期间的不同跟踪个体的位移-时间曲线重合的,可以认定为配对关系;重合部分的长短,则反映出配对关系的稳定性;巢址的位移-时间曲线间距,反映出巢址的变化。不同年份的巢址间距离,可以展示白头鹤具有很规则的领域回归行为。依据这些指标对跟踪的全部33只白头鹤的性别、年龄进行了判别。解读跟踪个体的配对、繁殖状况以及领域回归等。结果表明,基于卫星定位跟踪数据的位移-时间曲线与野外观察获得的信息相结合,为进一步挖掘卫星定位跟踪数据,推进被跟踪物种的深入分析提供了新的方法。

From 2014 to 2021,a total of 33 Hooded Cranes(Grus monacha)that came from rescue and field-capture were tracked and banded by satellite trackers,metal rings and colored plastic rings in Northeast China,the middle and lower reaches of the Yangtze River,Mongolia and Russia.After finding the breeding nests based on the tracking data,we arranged the infrared cameras around these nests.Our satellite tracking data came from 6 Hooded Cranes that were tracked more than 6 years and 7 Hooded Cranes summering and breeding in the north of Lesser Khingan Mountains.We took the zero point on May 15 as the reference point and used the set displacement-time calculation formula to convert the positioning coordinates into displacement-time curve which makes the obtained positioning data graphical.Then by combining the displacement-time curve and field behavior observation,we obtained discriminant indexes as follows:(a)Nocturnal roost site:the straightness of the nocturnal displacement-time curve in breeding or summering area reflects the change of the nocturnal roost site of the Hooded Crane;(b)Sex:judging from the straightness of the curve,the female is straight curve while the male is serrated curve;(c)Age:the sub adults are close to the breeding area and the curve changes greatly;within the breeding area,the curve of adults is almost flat for about 1 month;(d)Breeding:confirming whether the breeding is successful and the initial breeding age according to the length of the straight curve;(e)Pairing:if the displacement-time curves of different tracked individuals coincide from the beginning of April to the end of June,it can be recognized as a pairing relationship;the length of the coincidence part reflects the stability of the pairing relationship;(f)Nest sites and territory retention:the displacement-time curves of nest sites reflect the change of nest sites;the distance between nest sites in different years reveals that the Hooded Crane shows a very regular breeding territory retention.Overall,we identify the sex and age of the whole 33 tracked Hooded Cranes through the indexes above.Furthermore,we can interpret their status of pairing,breeding,territory retention and so on.The results of this study show that the combination of the displacement-time curve based on the satellite tracking data and field observation information provides a new method for further mining of satellite tracking data and further analysis of the tracked species.