Fortune may favor the flexible: Environment-dependent behavioral shifts in invasive coqui frogs

Abstract

Biological invasions are a major driver of global biodiversity loss, impacting endemic species, ecosystems, and economies. While the influence of life history traits on invasive success is well-established, the role of behavior in the invasive potential of animals is less studied. The common coqui frog, Eleutherodactylus coqui, is a highly successful invader in Hawaii. We build on previous research characterizing changes in physiology and morphology to explore behavioral variation across the invasive range of coqui in Hawaii. We hypothesized that behavioral traits contributing to invasion expansion would be reflected in behavioral differences at the invasive center versus invasive edge. To investigate whether differences in the field represent local adaptation or behavioral plasticity, we additionally evaluated behavior following acclimation to a shared laboratory environment. While we identified only subtle behavioral variation among populations in the field, we found that individuals from all populations became less bold, active, and exploratory in the laboratory, converging on a similar behavioral phenotype. Alongside previous work, our results suggest that coqui adjust their behavior to local environmental conditions across their invasive range, and that behavioral flexibility may contribute to invasive success.