Département Ecologie, Physiologie et Ethologie, Université de Strasbourg, IPHC, Strasbourg, France.
PLoS One. 2010 Nov 9;5(11):e13908. doi: 10.1371/journal.pone.0013908.
Sea turtles are long-distance migrants with considerable behavioural plasticity in terms of migratory patterns, habitat use and foraging sites within and among populations. However, for the most widely migrating turtle, the leatherback turtle Dermochelys coriacea, studies combining data from individuals of different populations are uncommon. Such studies are however critical to better understand intra- and inter-population variability and take it into account in the implementation of conservation strategies of this critically endangered species. Here, we investigated the movements and diving behaviour of 16 Atlantic leatherback turtles from three different nesting sites and one foraging site during their post-breeding migration to assess the potential determinants of intra- and inter-population variability in migratory patterns.
METHODOLOGY/PRINCIPAL FINDINGS: Using satellite-derived behavioural and oceanographic data, we show that turtles used Temporary Residence Areas (TRAs) distributed all around the Atlantic Ocean: 9 in the neritic domain and 13 in the oceanic domain. These TRAs did not share a common oceanographic determinant but on the contrary were associated with mesoscale surface oceanographic features of different types (i.e., altimetric features and/or surface chlorophyll a concentration). Conversely, turtles exhibited relatively similar horizontal and vertical behaviours when in TRAs (i.e., slow swimming velocity/sinuous path/shallow dives) suggesting foraging activity in these productive regions. Migratory paths and TRAs distribution showed interesting similarities with the trajectories of passive satellite-tracked drifters, suggesting that the general dispersion pattern of adults from the nesting sites may reflect the extent of passive dispersion initially experienced by hatchlings.
CONCLUSIONS/SIGNIFICANCE: Intra- and inter-population behavioural variability may therefore be linked with initial hatchling drift scenarios and be highly influenced by environmental conditions. This high degree of behavioural plasticity in Atlantic leatherback turtles makes species-targeted conservation strategies challenging and stresses the need for a larger dataset (>100 individuals) for providing general recommendations in terms of conservation.
海龟是长距离迁徙者，在迁徙模式、栖息地利用和种群内及种群间觅食地方面具有相当大的行为可塑性。然而，对于最广泛迁徙的海龟——棱皮龟 Dermochelys coriacea，结合不同种群个体数据的研究并不常见。然而，这种研究对于更好地了解种群内和种群间的变异性以及在实施这种极度濒危物种的保护策略时考虑到这种变异性至关重要。在这里，我们调查了来自三个不同筑巢地和一个觅食地的 16 只大西洋棱皮龟在繁殖后迁徙期间的运动和潜水行为，以评估迁徙模式中种群内和种群间变异性的潜在决定因素。
方法/主要发现：使用卫星衍生的行为和海洋学数据，我们表明海龟使用分布在整个大西洋的临时停留区（TRAs）：9 个在近岸域，13 个在大洋域。这些 TRA 没有共同的海洋学决定因素，但相反与不同类型的中尺度海洋表面特征相关（即，测高特征和/或表面叶绿素 a 浓度）。相反，海龟在 TRA 中表现出相对相似的水平和垂直行为（即，缓慢的游泳速度/弯曲路径/浅潜水），表明在这些多产区域进行觅食活动。迁徙路径和 TRA 分布与被动卫星跟踪漂流物的轨迹显示出有趣的相似性，表明来自筑巢地的成年个体的总体分散模式可能反映了幼龟最初经历的被动扩散程度。
结论/意义：因此，种群内和种群间的行为变异性可能与最初的幼龟漂移情景有关，并受到环境条件的高度影响。大西洋棱皮龟的这种高度行为可塑性使得针对物种的保护策略具有挑战性，并强调需要更大的数据集（>100 个个体），以便就保护提供一般性建议。
