Personality, density and habitat drive the dispersal of invasive crayfish

Shams M Galib,Jingrui Sun,Martyn C Lucas,Sean D Twiss

doi:10.1038/s41598-021-04228-1

Shams M Galib, Jingrui Sun + Show 2 more

Open Access

https://doi.org/10.1038/s41598-021-04228-1

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Abstract

There is increasing evidence that personality traits may drive dispersal patterns of animals, including invasive species. We investigated, using the widespread signal crayfish Pacifastacus leniusculus as a model invasive species, whether effects of personality traits on dispersal were independent of, or affected by, other factors including population density, habitat, crayfish size, sex and limb loss, along an invasion gradient. Behavioural traits (boldness, activity, exploration, willingness to climb) of 310 individually marked signal crayfish were measured at fully-established, newly-established and invasion front sites of two upland streams. After a period at liberty, recaptured crayfish were reassessed for behavioural traits (newly-established, invasion front). Dispersal distance and direction of crayfish movement, local population density, fine-scale habitat characteristics and crayfish size, sex and limb loss were also measured. Individual crayfish exhibited consistency in behavioural traits over time which formed a behavioural syndrome. Dispersal was both positively and negatively affected by personality traits, positively by local population density and negatively by refuge availability. No effect of size, sex and limb loss was recorded. Personality played a role in promoting dispersal but population density and local habitat complexity were also important determinants. Predicting biological invasion in animals is likely to require better integration of these processes.

Highlights

There is increasing evidence that personality traits may drive dispersal patterns of animals, including invasive species
We investigated whether behavioural traits indicative of boldness and exploration in signal crayfish were consistent over time, and whether these traits constituted a behavioural syndrome
This study provides evidence that dispersal of an invasive species under natural conditions can be driven by individual personality, but that population density and habitat characteristics are important factors as hypothesized (Fig. 4)

Summary

Introduction

There is increasing evidence that personality traits may drive dispersal patterns of animals, including invasive species. We investigated, using the widespread signal crayfish Pacifastacus leniusculus as a model invasive species, whether effects of personality traits on dispersal were independent of, or affected by, other factors including population density, habitat, crayfish size, sex and limb loss, along an invasion gradient. Individual crayfish exhibited consistency in behavioural traits over time which formed a behavioural syndrome Dispersal was both positively and negatively affected by personality traits, positively by local population density and negatively by refuge availability. Whether personality is h eritable[24], or a product of early developmental e nvironment[25,26], the existence of consistent individual differences in behavioural traits can have fundamental impacts on population ecological processes[8,10,27,28], as this difference between individuals can be important for successful resource acquisition and mating. Enhanced exploration and activity is often linked with increased fitness and more exploratory/active individuals are expected to play a key role in range expansion by dispersing further[12] but often expose themselves to greater predation

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