title: An approach to incorporate individual personality in modeling fish dispersal across in-stream barriers.
abstract: Animal personalities are an important factor that affects the dispersal of animals. In the context of aquatic species, dispersal modeling needs to consider that most freshwater ecosystems are highly fragmented by barriers reducing longitudinal connectivity. Previous research has incorporated such barriers into dispersal models under the neutral assumption that all migrating animals attempt to ascend at all times. Modeling dispersal of animals that do not perform trophic or reproductive migrations will be more realistic if it includes assumptions of which individuals attempt to overcome a barrier. We aimed to introduce personality into predictive modeling of whether a nonmigratory invasive freshwater fish (the round goby,Neogobius melanostomus) will disperse across an in-stream barrier. To that end, we experimentally assayed the personalities of 259 individuals from invasion fronts and established round goby populations. Based on the population differences in boldness, asociability, and activity, we defined a priori thresholds with bolder, more asocial, and more active individuals having a higher likelihood of ascent. We then combined the personality thresholds with swimming speed data from the literature and in situ measurements of flow velocities in the barrier. The resulting binary logistic regression model revealed probabilities of crossing a barrier which depended not only on water flow and fish swimming speed but also on animal personalities. We conclude that risk assessment through predictive dispersal modeling across fragmented landscapes can be advanced by including personality traits as parameters. The inclusion of behavior into modeling the spread of invasive species can help to improve the accuracy of risk assessments.
authors.affiliation: Research Centre for Sustainable Energy and Water Supply; Program Man-Society-Environment Department of Environmental Sciences University of Basel Basel Switzerland.
authors.forename: Philipp Emanuel
authors.identifier: 0000-0002-6927-2368
authors.initials: PE
authors.lastname: Hirsch
authors.affiliation: Department of Ecology and Environmental Science Umeå University Umeå Sweden.
authors.forename: Magnus
authors.initials: M
authors.lastname: Thorlacius
authors.affiliation: Department of Ecology and Environmental Science Umeå University Umeå Sweden.
authors.forename: Tomas
authors.initials: T
authors.lastname: Brodin
authors.affiliation: Research Centre for Sustainable Energy and Water Supply; Program Man-Society-Environment Department of Environmental Sciences University of Basel Basel Switzerland; Department of Biological Sciences University of Alberta Edmonton AB Canada.
authors.forename: Patricia
authors.initials: P
authors.lastname: Burkhardt-Holm
keywords: behavioral syndromes; ecological modeling; habitat fragmentation; invasive species; propagule pressure