Study of optimal foraging of diving seabirds with micro-time scale measurements of accceleration

众所周知，海鸟在调整体重后比海洋哺乳动物潜得更深、更长。许多实验室研究已经进行，以了解这种高潜水能力的生理和行为机制。由于其水下觅食必须在有限的氧气储备量下才能实现，因此也是研究最优觅食的良好材料。然而，由于能量消耗和食物摄入数据的收集困难，在野外的实证研究还很不足。我们测量了深潜海鸟在野外的潜水行为和捕食行为的细节，以研究潜水的成本和收益。我们的具体目标是了解鸟类在水中面对浮力和阻力时的高潜水能力和捕食的机制。为了评估翼击或足击的生物力学成本、栖息地利用和猎物捕获，我们在alci的背部安装了加速度记录数据记录器和摄像记录器 ...更多信息 DS和企鹅，和性交。1)我们提出了一个假设，shags平衡的成本增加中风率和通过增加游泳速度减少渡越时间的好处。我们发现2）专业潜水员（海鸟和海洋哺乳动物）减少中风频率与体重的幂函数（0.3）可能是为了保持一定的游泳速度范围（2 m/s），和3）飞行潜水海鸟，然而，有更高和更低的中风频率在空中和水中，分别比预期的，这表明一个补偿中风模式适合飞行和游泳。此外，我们提出了新的技术，以估计4）食物摄入量在每次觅食回合通过测量翅膀中风频率在短时间尺度（<10分钟）在飞行期间潜水回合和5）微栖息地的使用和猎物的追求通过采取图像数据，而觅食在底部阶段。为了了解海洋环境变化对觅食行为的精细调整的影响，我们研究了白令海海鸠的潜水和觅食行为。结果表明：1）海鸠潜水深度和觅食水体的变化与温跃层的变化及由此引起的猎物垂直分布有关; 2）亲鱼容易捕食小型猎物、磷虾和0龄青鳕，但深潜捕食大型鱼类和1+青鳕以提高供给率。少

Seabirds are known to dive deeper and longer than marine mammals after body mass is adjusted. Many laboratory studies have been carried out to understand the physiological and behavioural mechanisms of this high diving ability. Since its underwater foraging has to be achieved under limitation of with the limited amount of oxygen store, it is also a good material of the study of optimal foraging. Empirical study in the wild, however, has bee insufficient because of the difficulties collecting data of energetic cost and food intake. We measured detail of diving bahaviour and prey pursuit in deep diving seabirds in the wild to examine the cost and benefit of diving. Our specific aim is to understand the mechanism of high diving ability and prey intake when the birds face with the buoyancy and the drag in the water. To estimate biomechanical cost of wing or foot stroke, habitat utilization, and prey capture, we attached acceleration recording data-loggers and camera-loggers on back of alci … More ds and a penguin, and shags. 1) We proposed a hypothesis that shags balance the cost of increasing stroke rate and the benefit of the reduction of transit time by increasing swim speed. We found that 2) specialist divers (seabirds and marine mammals) decrease the frequency of stroke with the power function of body mass (0.3) presumably to keep a range of swim speed (2m/s), and 3) flying-diving seabirds, however, had higher and lower stroke frequency in the air and water, respectively, than expected; indicating a compensated stroke pattern suitable for flying and swimming. Further, we proposed new techniques to estimate 4) food intake during a each foraging bout by measuring wing stroke frequency at short time scale (<10min) during the flight period between diving bouts and 5) micro habitat use and prey pursuit by taking image data while foraging during bottom phase. To understand the effects of marine environmental change on fine scale adjustment of foraging behaviour, we studied diving and foraging behaviour of guillemots in the Bering Sea. We found that 1) guillemots changed dive depth and foraging water masses in relation to the change of thermocline and resulting vertical distribution of prey, 2) parents forage easily collected small prey, krill and 0-year-pollack for themselves but dove deep to capture large fish and 1+ Pollack to increase provisioning rate. Less