Prospecting and dispersal: their eco-evolutionary dynamics and implications for population patterns

Abstract

Dispersal is not a blind process, and evidence is accumulating that individual dispersal strategies are informed in most, if not all, organisms. The acquisition and use of information are traits that may evolve across space and time as a function of the balance between costs and benefits of informed dispersal. If information is available, individuals can potentially use it in making better decisions, thereby increasing their fitness. However, prospecting for and using information probably entail costs that may constrain the evolution of informed dispersal, potentially with population-level consequences. By using individual-based, spatially explicit simulations, we detected clear coevolutionary dynamics between prospecting and dispersal movement strategies that differed in sign and magnitude depending on their respective costs. More specifically, we found that informed dispersal strategies evolve when the costs of information acquisition during prospecting are low but only if there are mortality costs associated with dispersal movements. That is, selection favours informed dispersal strategies when the acquisition and use processes themselves were not too expensive. When non-informed dispersal strategies evolve, they do so jointly with the evolution of long dispersal distance because this maximizes the sampling area. In some cases, selection produces dispersal rules different from those that would be 'optimal' (i.e. the best possible population performance-in our context quantitatively measured as population density and patch occupancy-among all possible individual movement rules) for the population. That is, on the one hand, informed dispersal strategies led to population performance below its highest possible level. On the other hand, un-and poorly informed individuals nearly optimized population performance, both in terms of density and patch occupancy.

Predicting population responses to environmental change: the importance of considering informed dispersal strategies in spatially structured population models

“…It is of course well-known that dispersal affects metapopulation dynamics (Hanski, 1998), but the consequences of individual behavioural strategies on the spatial and temporal dynamics of subdivided populations remain unclear Doligez et al, 2003;Delgado et al, 2014). Crucially, our results demonstrate that dispersal strategies strongly and differently influence population dynamics, structure and persistence when the environment is spatially and temporally variable.…”

Prospecting precedes dispersal and increases survival chances in cooperatively breeding cichlids

“…Other potential benefits of such between-group visits have also been proposed, e.g. extragroup matings (Young, Spong, & Clutton-Brock, 2007) or the establishment of safe havens (Bergmüller, Heg, Peer, et al, 2005), besides their potential importance for dispersal (Bergmüller, Heg, Peer, et al, 2005;Cox & Kesler, 2012;Delgado et al, 2014;Doolan & Macdonald, 1996;Kesler & Haig, 2007). Thus, in many cooperative species, individuals appear to build familiarity networks outside their own group by visiting and interacting with foreign groups.…”

“…Owing to a lack of knowledge about and familiarity with the new environment, dispersal can be a costly enterprise (Bonte et al, 2012). To mitigate this cost, animals may prospect the environment within their potential dispersal range to obtain information about dispersal options (Bocedi, Heinonen, & Travis, 2012;Delgado, Barton, Bonte, & Travis, 2014;Ponchon, Garnier, Gr emillet, & Boulinier, 2015). Indeed, dispersal decisions often appear to be informed and based on an evaluation of the current and potential future habitat (Clobert, Le Galliard, Cote, Meylan, & Massot, 2009).…”

Life history trade-offs imposed by dragline use in two money spiders

“…when the chances of reaching suitable habitat are low (Bonte et al, 2006). Costs incurred during different dispersal stages (initiation, transfer and settlement) eventually determine dispersal strategies and feed back among each other Delgado et al, 2014;Travis et al, 2012). We demonstrated here trade-offs between silk spinning and fitness-related life history components, with an overall effect under dietary restriction.…”