Recently, an article about the causes of behavioral differentiation among shrews, by Leszek Rychlik and co-authors from Portugal (University of Lisbon) and Germany (University of Munich), appeared, in its final form, in Behavioral Ecology and Sociobiology. Comparing the behavior in five species of shrews from several locations in Europe, the authors tested if fast-lived species would differ in average levels of behavior (boldness and aggression), as well as would show lower within-individual and among-individual variation than slow-lived ones. While the average levels of species’ behavior indeed matched their pace of life, their individual behavior and behavioral stability did not. It was rather explained by an interplay of ecological and physiological factors, as the variability in habitat choices and differences in anti-predator strategies. This study shows that behavioral variation cannot be explained by just one factor like pace-of-life syndrome at different hierarchical levels, but rather by a combination of factors including the animals’ life-history and ecological and physiological background.


The paper is available at: