Abstract: Human disturbance including rapid urbanization and increased temperatures can have profound effects on the ecology of local populations. Ants have adapted to stressors of increasing temperature and urbanization, however these evolutionary responses are not consistent among populations across geographic space. Here we asked how urbanization and incubation temperature influence critical thermal maximum (CTmax) and various ecologically relevant behaviors in three ant species in urban and rural locations in Worcester, MA, USA. We did this by incubating colonies of three species of cavity dwelling ant (Aphaenogaster. picea, Tapinoma sessile, and Temnothorax longispinosus) from 2 habitat types (Rural and Urban), for 60-days at multiple temperatures. We found that incubation temperature, urbanization status and species of ant all significantly affected overall colony critical thermal maximum. We also found that recruitment time, colonization time and aggression were significantly affected by incubation temperature and varied between species of ant, while recruitment and colonization time were additionally affected by urbanization status. These variable changes in performance and competitive across species suggest that responses to urbanization and shifting temperatures are not universal across species. Changes in behavioral responses caused by urbanization may disrupt biodiversity, creating unusual competitive environments as a consequence of natural adaptations and cause both direct and indirect mechanisms for which human disturbance can lead to local species extinction.
