Characteristics of exotic ants in North America

Abstract

Th worldwide transport of species beyond their native range is an increasing problem, e.g. for global biodiversity. Many introduced species are able to establish in new environments and some even become invasive. However, we do not know which traits enable them to survive and reproduce in new environments. Ths study aims to identify the characteristics of exotic ants, and to quantitatively test previously postulated but insuffiently tested assumptions. We collected data on nine traits of 93 exotic ant species (42 of them being invasive) and 323 native ant species in North America. Th dataset includes 2536 entries from over 300 diffrent sources; data on worker head width were mostly measured ourselves. We analyzed the data with three complementary analyses: univariate and multivariate analyses of the raw data, and multivariate analyses of phylogenetically independent contrasts. Thse analyses revealed signifiant diffrences between the traits of native and exotic ant species. In the multivariate analyses, only one trait was consistently included in the best models, estimated with AICc values: colony size. Ths, of the nine investigated traits, the most important characteristic of exotic ants as compared to native ants appears to be their large colony size. Other traits are also important, however, indicating that native and exotic ants diffr by a suite of traits.