Seasonal modulation of flight speed among nocturnal passerine migrants: differences between short- and long-distance migrants
Seasonal modulation of flight speed among nocturnal passerine migrants: differences between short- and long-distance migrants
复制标题
夜间雀形目候鸟飞行速度的季节性调节：短途和长途候鸟之间的差异
DOI：
10.1007/s00265-014-1789-5
复制
发表时间：
2014
影响因子：
2.3
通讯作者：
T. Alerstam
中科院分区：
文献类型：
--
作者：
C. Nilsson;J. Bäckman;T. Alerstam
候鸟预计会以更高的空速飞行，以最大限度地减少迁徙过程中的时间而不是能源成本。春季迁徙通常被认为比秋季迁徙选择更多的时间，因为春季迁徙具有较早到达繁殖地的优势。我们之前已经证明，与秋季相比，夜间活动的雀形目迁徙者在春季以更高的空速飞行，支持了春季迁徙的时间选择。在这项研究中，我们检验了这样的假设：由于秋季长距离迁徙的时间选择因素更强，短途和长途迁徙者之间的季节性空速受到不同的调节。为了支持这一假设，我们证明，与长距离（1.12 倍）移民相比，短距离移民的空速季节性差异显着更大（在校正高度、风和爬升/下降对空速的影响后，春季空速超过秋季空速 1.16 倍）。该结果基于瑞典南部法尔斯特博 3 年跟踪雷达数据的大样本。短途候鸟在秋季也往往会在更有利的风向下飞行，这表明与长途候鸟相比，时间限制更宽松（能够等待有利的风向）。这些结果表明，空速和对风的响应的季节性调节令人惊讶，这与适应春季和秋季迁徙期间不同水平的时间选择压力的行为策略相关。
Migrating birds are expected to fly at higher airspeeds when minimizing time rather than energy costs of their migratory journeys. Spring migration has often been suggested to be more time selected than autumn migration, because of the advantage of early arrival at breeding sites. We have earlier demonstrated that nocturnal passerine migrants fly at higher airspeeds during spring compared to autumn, supporting time-selected spring migration. In this study, we test the hypothesis that seasonal airspeeds are modulated differently between short- and long-distance migrants, because of a stronger element of time selection for autumn migration over long distances. In support of this hypothesis, we demonstrate that the seasonal difference in airspeed is significantly larger (spring airspeed exceeding autumn airspeed by a factor of 1.16 after correcting for the influence of altitude, wind and climb/descent on airspeed) among short-distance compared to long-distance (factor 1.12) migrants. This result is based on a large sample of tracking radar data from 3 years at Falsterbo, South Sweden. Short-distance migrants also tend to fly with more favourable winds during autumn, indicating relaxed time constraints (being able to afford to wait for favourable winds) compared to long-distance migrants. These results indicate surprisingly fine-tuned seasonal modulation of airspeed and responses to wind, associated with behavioural strategies adapted to different levels of time selection pressures during spring and autumn migration.