Publications des scientifiques de l'IRD

Bertrand Sophie, Joo Rocio, Fablet Ronan. (2015). Generalized Pareto for pattern-oriented random walk modelling of organisms' movements. Plos One, 10 (7), e0132231 [16 p.]. ISSN 1932-6203.

Titre du document
Generalized Pareto for pattern-oriented random walk modelling of organisms' movements
Année de publication
2015
Type de document
Article référencé dans le Web of Science WOS:000358194900037
Auteurs
Bertrand Sophie, Joo Rocio, Fablet Ronan
Source
Plos One, 2015, 10 (7), e0132231 [16 p.] ISSN 1932-6203
How organisms move and disperse is crucial to understand how population dynamics relates to the spatial heterogeneity of the environment. Random walk (RW) models are typical tools to describe movement patterns. Whether Levy or alternative RW better describes forager movements is keenly debated. We get around this issue using the Generalized Pareto Distribution (GPD). GPD includes as specific cases Normal, exponential and power law distributions, which underlie Brownian, Poisson-like and Levy walks respectively. Whereas previous studies typically confronted a limited set of candidate models, GPD lets the most likely RW model emerge from the data. We illustrate the wide applicability of the method using GPS-tracked seabird foraging movements and fishing vessel movements tracked by Vessel Monitoring System (VMS), both collected in the Peruvian pelagic ecosystem. The two parameters from the fitted GPD, a scale and a shape parameter, provide a synoptic characterization of the observed movement in terms of characteristic scale and diffusive property. They reveal and quantify the variability, among species and individuals, of the spatial strategies selected by predators foraging on a common prey field. The GPD parameters constitute relevant metrics for (1) providing a synthetic and pattern-oriented description of movement, (2) using top predators as ecosystem indicators and (3) studying the variability of spatial behaviour among species or among individuals with different personalities.
Plan de classement
Sciences fondamentales / Techniques d'analyse et de recherche [020] ; Ecologie, systèmes aquatiques [036]
Localisation
Fonds IRD [F B010064851]
Identifiant IRD
fdi:010064851
Contact