Brigatti E, Ríos-Uzeda B, Vieira M V
Instituto de Física, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 149, Cidade Universitária, Rio de Janeiro, RJ, 21941-972, Brazil.
Laboratório de Vertebrados, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Caixa Postal 68020, Rio de Janeiro, RJ, 21941-590, Brazil.
Mov Ecol. 2024 Mar 25;12(1):23. doi: 10.1186/s40462-024-00465-x.
We record and analyze the movement patterns of the marsupial Didelphis aurita at different temporal scales. Animals trajectories are collected at a daily scale by using spool-and-line techniques and, with the help of radio-tracking devices, animals traveled distances are estimated at intervals of weeks. Small-scale movements are well described by truncated Lévy flight, while large-scale movements produce a distribution of distances which is compatible with a Brownian motion. A model of the movement behavior of these animals, based on a truncated Lévy flight calibrated on the small scale data, converges towards a Brownian behavior after a short time interval of the order of 1 week. These results show that whether Lévy flight or Brownian motion behaviors apply, will depend on the scale of aggregation of the animals paths. In this specific case, as the effect of the rude truncation present in the daily data generates a fast convergence towards Brownian behaviors, Lévy flights become of scarce interest for describing the local dispersion properties of these animals, which result well approximated by a normal diffusion process and not a fast, anomalous one. Interestingly, we are able to describe two movement phases as the consequence of a statistical effect generated by aggregation, without the necessity of introducing ecological constraints or mechanisms operating at different spatio-temporal scales. This result is of general interest, as it can be a key element for describing movement phenomenology at distinct spatio-temporal scales across different taxa and in a variety of systems.
我们记录并分析了有袋动物南美袋鼬在不同时间尺度下的运动模式。通过使用卷轴线技术在每日尺度上收集动物的轨迹，并借助无线电追踪设备，以周为间隔估算动物的移动距离。小规模运动可用截断的 Lévy 飞行很好地描述，而大规模运动产生的距离分布与布朗运动相符。基于在小规模数据上校准的截断 Lévy 飞行的这些动物运动行为模型，在大约 1 周的短时间间隔后会趋向于布朗行为。这些结果表明，Lévy 飞行行为还是布朗运动行为适用，将取决于动物路径的聚集尺度。在这种特定情况下，由于每日数据中存在的粗暴截断效应会导致快速趋向于布朗行为，Lévy 飞行对于描述这些动物的局部分散特性变得不太重要，其结果可用正态扩散过程而非快速、异常的过程很好地近似。有趣的是，我们能够将两个运动阶段描述为聚集产生的统计效应的结果，而无需引入在不同时空尺度上运作的生态约束或机制。这一结果具有普遍意义，因为它可能是描述不同分类群和各种系统中不同时空尺度下运动现象学的关键要素。
