Data from: Intraspecific trait variation is correlated with establishment success of alien mammals

Many studies have aimed to identify common predictors of successful
introductions of alien species, but the search has had limited success,
particularly for animals. Past research focused primarily on mean trait
values even though genetic and phenotypic variation have been shown to
play a role in establishment success in plants and some animals (mostly
invertebrates). Using a global database describing 511 introduction events
representing 97 mammalian species, we show that intraspecific variation in
morphological traits is associated with establishment success, even when
controlling for the positive effect of propagule pressure. In particular,
greater establishment success is associated with more variation in adult
body size but surprisingly, less variation in neonate body size,
potentially reflecting distinct trade-offs and constraints that influence
population dynamics differently. We find no mean trait descriptors
associated with establishment success, although species occupying wider
native distribution ranges (which likely have larger niches) are more
successful. Our results emphasize the importance of explicitly considering
intraspecific variation to predict establishment success in animal
species, and generally to understand population dynamics. This
understanding might improve management of alien species and increase the
success of intentional releases, e.g. for biocontrol or reintroductions.