Bennison Ashley, Bearhop Stuart, Bodey Thomas W, Votier Stephen C, Grecian W James, Wakefield Ewan D, Hamer Keith C, Jessopp Mark
MaREI Centre for Marine and Renewable Energy Environmental Research Institute University College Cork Cork Ireland.
School of Biological Earth, and Environmental Sciences (BEES) University College Cork Cork Ireland.
Ecol Evol. 2017 Nov 23;8(1):13-24. doi: 10.1002/ece3.3593. eCollection 2018 Jan.
Search behavior is often used as a proxy for foraging effort within studies of animal movement, despite it being only one part of the foraging process, which also includes prey capture. While methods for validating prey capture exist, many studies rely solely on behavioral annotation of animal movement data to identify search and infer prey capture attempts. However, the degree to which search correlates with prey capture is largely untested. This study applied seven behavioral annotation methods to identify search behavior from GPS tracks of northern gannets (), and compared outputs to the occurrence of dives recorded by simultaneously deployed time-depth recorders. We tested how behavioral annotation methods vary in their ability to identify search behavior leading to dive events. There was considerable variation in the number of dives occurring within search areas across methods. Hidden Markov models proved to be the most successful, with 81% of all dives occurring within areas identified as search. -Means clustering and first passage time had the highest rates of dives occurring outside identified search behavior. First passage time and hidden Markov models had the lowest rates of false positives, identifying fewer search areas with no dives. All behavioral annotation methods had advantages and drawbacks in terms of the complexity of analysis and ability to reflect prey capture events while minimizing the number of false positives and false negatives. We used these results, with consideration of analytical difficulty, to provide advice on the most appropriate methods for use where prey capture behavior is not available. This study highlights a need to critically assess and carefully choose a behavioral annotation method suitable for the research question being addressed, or resulting species management frameworks established.
在动物运动研究中，搜索行为常被用作觅食努力的替代指标，尽管它只是觅食过程的一部分，觅食过程还包括猎物捕获。虽然存在验证猎物捕获的方法，但许多研究仅依赖于对动物运动数据的行为注释来识别搜索行为并推断猎物捕获尝试。然而，搜索与猎物捕获之间的关联程度在很大程度上未经测试。本研究应用了七种行为注释方法，从北方塘鹅的GPS轨迹中识别搜索行为，并将输出结果与同时部署的时间深度记录器记录的潜水发生情况进行比较。我们测试了行为注释方法在识别导致潜水事件的搜索行为能力方面的差异。不同方法识别出的搜索区域内发生的潜水数量存在相当大的差异。隐马尔可夫模型被证明是最成功的，所有潜水中有81%发生在被识别为搜索的区域内。 -均值聚类和首次通过时间在被识别的搜索行为之外发生潜水的比例最高。首次通过时间和隐马尔可夫模型的误报率最低，识别出的无潜水搜索区域较少。就分析的复杂性以及在最小化误报和漏报数量的同时反映猎物捕获事件的能力而言，所有行为注释方法都有优点和缺点。我们结合分析难度考虑这些结果，为在没有猎物捕获行为的情况下使用最合适的方法提供建议。本研究强调需要批判性地评估并谨慎选择适合所研究问题或由此建立的物种管理框架的行为注释方法。
