Data for "Linking ringed seal foraging behaviour to environmental variability"

These datasets are for replicating the hidden Markov models and generalized additive mixed models in the article "Linking ringed seal foraging behaviour to environmental variability" Abstract Background: Foraging rates directly influence animals’ energetic intake and expenditure and are thus linked to body condition and the ability to survive and reproduce. Further, understanding the underlying processes driving a species’ behaviour and habitat use is important as changes in behaviour could result from changes in environmental conditions.Methods: In this study, the dives of Saimaa ringed seals (Pusa hispida saimensis) were classified for the first time using hidden Markov models and telemetry data collected on individual dives, and the behavioural states of the diving seals were estimated. In addition, we used generalized additive mixed models on the foraging probability of the seals to identify environmental and temporal drivers of foraging behaviour. Results: We inferred three (in winter) or four (in summer) different dive types: sleeping/resting dives, shallow inactive dives, transiting dives and foraging dives, based on differences in dive metrics logged by or derived from data from telemetry tags. Long and relatively deep sleeping/resting dives were missing entirely in the winter, compensated by an increased proportion of time used for haul-out. We found profound differences in the behaviour of Saimaa ringed seals during the open water season compared to the ice-covered winter, with the greatest proportion of time allocated to foraging during the summer months (36%) and the lowest proportion in the winter (21%). The seals’ foraging probability peaked in summer (July) and was highest during the daytime during both summer and winter months. Moreover, foraging probability was highest at lake depths of 7-30 m in the winter and at depths >15 m in the summer. We also found some evidence of sex-specific foraging strategies that are adapted seasonally, with females preferring more sheltered water areas during winter. Conclusions: We suggest that the foraging behaviour of Saimaa ringed seals is largely influenced by diel vertical movements and availability of fish, and that the seals optimize their energy acquisition while conserving energy, especially during the cold winter months. Further, the seals display some flexibility in foraging strategies, a feature that may help this endangered subspecies to cope with the ongoing climate change.本数据集旨在复现论文《环斑海豹觅食行为与环境变异性的关联》（"Linking ringed seal foraging behaviour to environmental variability"）中所使用的隐马尔可夫模型（hidden Markov models）与广义加性混合模型（generalized additive mixed models）。 摘要 背景：觅食速率直接影响动物的能量摄入与消耗，因此与身体状况、生存及繁殖能力息息相关。此外，理解驱动物种行为与栖息地利用的内在过程至关重要，因为行为变化可能源于环境条件的改变。 方法：本研究首次利用隐马尔可夫模型，结合单次潜水采集的遥测数据，对塞马环斑海豹（Pusa hispida saimensis）的潜水行为进行分类，并估算了潜水海豹的行为状态。此外，我们针对海豹的觅食概率构建广义加性混合模型，以识别影响觅食行为的环境与时间驱动因子。 结果：基于遥测标签记录或衍生的潜水指标差异，我们推断出冬季3种、夏季4种不同的潜水类型：睡眠/休息潜水、浅层非活动潜水、巡游潜水以及觅食潜水。冬季完全不存在长时且相对较深的睡眠/休息潜水，取而代之的是海豹增加了上岸休憩的时间占比。我们发现，与冰封冬季相比，塞马环斑海豹在敞水季的行为存在显著差异：夏季月份的觅食时间占比最高（36%），冬季则最低（21%）。海豹的觅食概率在夏季（7月）达到峰值，且在夏冬两季均于日间达到最高。此外，冬季的最高觅食概率出现在7-30米的湖域水深，夏季则出现在水深大于15米的区域。我们还发现了一些证据表明，海豹存在随季节适应的性别特异性觅食策略：雌性在冬季更偏好栖息于更为隐蔽的水域。 结论：我们认为，塞马环斑海豹的觅食行为在很大程度上受昼夜垂直移动与鱼类可获得性的影响，且海豹会优化能量获取效率同时节约能量，尤其在寒冷的冬季。此外，海豹在觅食策略上展现出一定的灵活性，这一特性或许能帮助这一濒危亚种应对持续的气候变化。