Horizontal and vertical movements as predictors of foraging success in a marine predator
Horizontal and vertical movements as predictors of foraging success in a marine predator
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DOI：
10.3354/meps09498
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发表时间：
2012-01-01
影响因子：
2.5
通讯作者：
Guinet, Christophe
中科院分区：
文献类型：
--
作者：
Dragon, Anne-Cecile;Bar-Hen, Avner;Guinet, Christophe
随着野生动物遥测技术的进步，对神秘捕食者对猎物分布的反应的研究已经发生了革命性的变化。在海洋捕食者的情况下，最近开发了高分辨率的标记设备，以收集精确的潜水数据集，涵盖很长一段时间。在这项研究中，我们调查的水平运动和潜水模式的海洋捕食者，南象海豹，在精细的时间和空间尺度的变化。用切换状态空间模型处理了9个密封件的卫星跟踪数据。海豹身体状况，作为觅食成功的代理，估计通过时间深度记录仪（TDR）数据漂移率的变化。我们从跟踪数据中识别出（1）统计上不同的行为模式（密集与广泛的觅食模式）和（2）从TDR潜水数据中识别出不同的潜水类别（漂移，探索，浅主动和深主动潜水）。活跃的潜水，与垂直觅食和追逐，更多的海豹时，在密集的觅食模式。海豹的身体状况和体重增加的改善也与密集的觅食模式有关，在垂直方向上，与高度活跃的潜水组有关。总之，潜水类的比例根据海豹的水平行为而变化。从表面跟踪数据检测到的密集觅食是一个很好的预测潜水活动和觅食成功发生在垂直方向。
With technical advances in wildlife telemetry, the study of cryptic predators' responses to prey distribution has been revolutionised. In the case of marine predators, high resolution tagging devices have been developed recently to collect precise diving datasets covering extended periods of time. In this study, we investigated changes in the horizontal movements and diving patterns of a marine predator, the southern elephant seal, at fine temporal and spatial scales. Satellite tracking data collected for 9 seals were processed with switching state-space models. Seal body condition, as a proxy for foraging success, was estimated through changes in drift rate from Time Depth Recorder (TDR) data. We identified (1) statistically distinct behavioural modes from the tracking data (intensive vs. extensive foraging modes) and (2) distinct dive classes from the TDR diving data (drift, exploratory, shallow active and deep active dives). Active dives, associated with vertical foraging and chasing, were more numerous when the seals were in intensive foraging mode. Improved body condition and mass gain of seals were also associated with the intensive foraging mode and, within the vertical dimension, with sets of highly active dives. In conclusion, proportions of dive classes varied according to seals' horizontal behaviour. Intensive foraging detected from surface tracking data is a good predictor of diving activity and foraging success occurring in the vertical dimension.