Dispersal has gained increased attention because of its fundamental role in determining biodiversity responses to rapid global changes. Recently acquired ecological and evolutionary knowledge suggests an inter-dependency of dispersal with diverse suites of traits in semi- or terrestrial organisms. However, connectivity in river networks represents another constraint to dispersal in freshwater environments, which may challenge the predictive utility of dispersal syndromes for conservation and management. Here, we asked whether dispersal in stream fishes (1) is a fixed property of species and (2) correlated with life history, ecological and behavioral traits. We performed a systematic review of the literature to collect estimates of dispersal from capture-recapture and radio-tracking studies and estimated dispersal distances using various percentiles of the dispersal kernels fitted to empirical distributions. Relationships between dispersal and species’ traits were then tested using Bayesian multivariate mixed-effects models, accounting for phylogenetic and spatial dependencies among estimates.
Results/Conclusions
Based on a final dataset comprising 118 species and 201 locations for which phylogeny, traits and quantitative estimates of dispersal distances were available, our meta-analysis revealed that dispersal (1) is highly repeatable within individual species, especially regarding long-distance movements, and (2) is correlated with a combination of multiple traits. In particular, we identified strong inter-dependencies with species life history strategy, ecological specialization, habitat stability, swimming skill and feeding behavior. We also showed that whereas the strength of the association with life history traits increased with increasing dispersal distances, the opposite trend was observed for habitat stability, suggesting that short- and long-distance dispersal are underlined to some extent by distinct mechanisms. Together, these results demonstrate that similarly to their terrestrial counterparts, the existence of dispersal syndromes in freshwater species offer opportunities for biodiversity conservation to better anticipate species responses in a rapidly changing world.