■已经开发了多种方法来从动物运动数据中推断行为状态,但是很少有独立证据评估它们的准确性,特别是对于以高时间分辨率采样的位置数据。在这里,我们使用监视猎物捕获尝试的声音记录来评估行为分割方法的性能。
■我们在11只墨西哥食鱼蝙蝠的觅食之旅中记录了GPS位置和超声波音频,MyotisVivesi,使用微型生物记录器。然后,我们应用了五种不同的分割算法(k均值聚类,期望最大化和二元聚类,第一次通过时间,隐马尔可夫模型,和相关的速度变化点分析)来推断两种行为状态,觅食和通勤,从GPS数据。为了评估推断,我们独立地确定了在录音中觅食期间发生的Biosonar叫声(“喂食蜂鸣声”)的特征模式。然后,我们比较了分割方法,以确定它们正确识别这两种行为的程度,以及它们对觅食运动参数的估计是否与有嗡嗡声的位置相匹配。
■虽然五种方法在预测的觅食事件期间发生的嗡嗡声的中位数百分比不同,或真阳性率(44-75%),两状态隐马尔可夫模型的中值平衡准确率最高(67%).隐马尔可夫模型和首次通过时间预测的觅食飞行速度和转弯角度与在有觅食蜂鸣的位置测得的速度和转弯角度相似,并且预测的觅食事件的数量或持续时间没有差异。
■隐马尔可夫模型方法在识别食鱼蝙蝠觅食段方面表现最好;然而,首次传代时间没有显著差异,并给出了相似的参数估计.这是首次尝试评估回声定位蝙蝠的分割方法,并提供了可用于其他物种的评估框架。
UNASSIGNED: Multiple methods have been developed to infer behavioral states from animal movement data, but rarely has their accuracy been assessed from independent evidence, especially for location data sampled with high temporal resolution. Here we evaluate the performance of behavioral segmentation methods using acoustic recordings that monitor prey capture attempts.
UNASSIGNED: We recorded GPS locations and ultrasonic audio during the
foraging trips of 11 Mexican fish-eating bats, Myotis vivesi, using miniature bio-loggers. We then applied five different segmentation algorithms (k-means clustering, expectation-maximization and binary clustering, first-passage time, hidden Markov models, and correlated velocity change point analysis) to infer two behavioral states,
foraging and commuting, from the GPS data. To evaluate the inference, we independently identified characteristic patterns of biosonar calls (\"feeding buzzes\") that occur during foraging in the audio recordings. We then compared segmentation methods on how well they correctly identified the two behaviors and if their estimates of foraging movement parameters matched those for locations with buzzes.
UNASSIGNED: While the five methods differed in the median percentage of buzzes occurring during predicted
foraging events, or true positive rate (44-75%), a two-state hidden Markov model had the highest median balanced accuracy (67%). Hidden Markov models and first-passage time predicted
foraging flight speeds and turn angles similar to those measured at locations with feeding buzzes and did not differ in the number or duration of predicted
foraging events.
UNASSIGNED: The hidden Markov model method performed best at identifying fish-eating bat foraging segments; however, first-passage time was not significantly different and gave similar parameter estimates. This is the first attempt to evaluate segmentation methodologies in echolocating bats and provides an evaluation framework that can be used on other species.