Laboratoire Matière et Systèmes Complexes

Understanding the nature of foraging : fractal bugs, the math behind them, and what we can learn from behavioural complexity ?

Laurent Seuront, CNRS UMR 8187 Laboratoire d’Océanologie et de Géosciences (LOG) Station Marine, Wimereux, France

Both terrestrial and aquatic ecosystems have long been acknowledged to be highly structured and variable in both space and time over a considerable range of scales. There is still, however, a potentially detrimental lack of consensus on how to approach this complexity, as most – if not all – research areas are implicitly bound to a specific range of scales and/or specific organisms. In this context, I will illustrate how concepts and tools borrowed to the field of chaos theory and nonlinear physics as well as newly developed purpose-designed techniques can be uniquely used to characterize both the qualitative and quantitative nature of Nature’s complexity across a range of phyla and taxa (typically from microbes to mammals) – hence of range of scales (from micrometres to kilometres) – in various habitats in both terrestrial and aquatic environments considered under various climatic regimes (from polar to tropical). This system approach is based on the recognition that details matter, that is a thorough understanding of (i) the nature of abiotic and biotic habitat properties at scales pertinent to individual organisms and (ii) the behavioural properties of these organisms are critical to understand the fundamental nature of the complexity of interactions that rule the structure and function of ecosystems. Specifically, I will discuss how the consideration of the details of the interplay between behavioural strategies and environmental heterogeneity can deeply challenge our understanding of key issues such as carbon fluxes estimates, the ability of organisms to face climate change, and assessing stress levels at both the individual and ecosystem level. I will finally discuss how this approach may typically lead to entangle the ‘chicken or chicken-egg’ question of understanding the mechanisms that generate the observed patterns and processes, and their potential links with and effects on the spatial patterns of resources and habitats.