Data from: Activity and migratory flights of individual free-flying songbirds throughout the annual cycle: method and first case study

We describe a method and device (< 1.2 g) for recording, processing and storing data about activity and location of individuals of free-living songbirds throughout the annual cycle.Activity level was determined every five minutes from five 100 ms samples of accelerometer data with 5 s between the sampling events. Activity levels were stored on an hourly basis throughout the annual cycle, allowing periods of resting/ sleep, continuous flight and intermediate activity (foraging, breeding) to be distinguished. Measurements from a light sensor were stored from preprogrammed key stationary periods during the year to provide control information about geographic location.Successful results, including annual actogram, were obtained for a red-backed shrike Lanius collurio carrying out its annual loop migration between northern Europe and southern Africa. The shrike completed its annual migration by performing > 66 (max. 73) nocturnal migratory flights (29 flights in autumn and > 37, max. 44, in spring) adding up to a total of > 434 (max. 495) flight hours. Migratory flights lasted on average 6.6 h with maximum 15.9 h. These flights were aggregated into eight travel episodes (periods of 4–11 nights when flights took place on the majority of nights). Daytime resting levels were much higher during the winter period compared to breeding and final part of spring migration. Daytime resting showed peaks during days between successive nocturnal flights across Sahara, continental Africa and the Arabian Peninsula, indicating that the bird was mostly sleeping between these long migratory flights.Annual activity and flight data for free-living songbirds will open up many new research possibilities. Main topics that can be addressed are e.g. migratory flight performance (total flight investment, numbers and characteristics of flights), timing of stationary periods, activity patterns (resting/sleep, activity level) in different phases of the annual cycle and variability in the annual activity patterns between and within individuals.

本研究报道了一种重量小于1.2克的方法与装置，可对自由活动鸣禽个体在全年周期内的活动与位置相关数据进行记录、处理与存储。活动水平每5分钟判定一次，基于5次间隔5秒的100毫秒加速度计（accelerometer）数据采样完成。活动水平数据将按小时存储于全年周期中，借此可区分休息/睡眠、持续飞行以及中等活动（觅食、繁殖）等不同行为时段。光传感器（light sensor）的测量数据将在全年预编程的关键静止时段存储，用于提供个体地理位置的对照佐证信息。针对在北欧与南非之间开展年度环形迁徙的红背伯劳（Lanius collurio），本装置已获取包含年度活动节律图（actogram）在内的成功实验结果。该红背伯劳通过完成66次以上（最多73次）夜间迁徙飞行完成年度迁徙：秋季飞行29次，春季飞行37次以上、最多44次，总飞行时长超过434小时（最长可达495小时）。单次迁徙飞行平均时长为6.6小时，最长可达15.9小时。这些迁徙飞行被整合为8个旅行阶段（即4至11晚的时段，其中多数夜晚均有飞行行为）。相较于繁殖期与春季迁徙末期，冬季的日间休息水平显著更高。在横跨撒哈拉沙漠、非洲大陆与阿拉伯半岛的连续夜间飞行之间的时段，日间休息水平出现峰值，表明该个体在这些长距离迁徙飞行之间主要处于睡眠状态。针对自由活动鸣禽的全年活动与飞行数据将为诸多全新研究方向提供可能。可开展的核心研究主题包括：迁徙飞行表现（总飞行投入、飞行次数与飞行特征）、静止时段的时间安排、全年周期不同阶段的活动模式（休息/睡眠、活动水平），以及个体间与个体内全年活动模式的变异性。