Climate matching and anthropogenic factors contribute to the colonization and extinction of local populations during avian invasions

Aim Concern about the impacts of biological invasions has generated a great deal of interest in understanding factors that determine invasion success. Most of our current knowledge comes from static approaches that use spatial patterns as a proxy of temporal processes. These approaches assume that species are present in areas where environmental conditions are the most favourable. However, this assumption is problematic when applied to dynamic processes such as species expansions when equilibrium has not been reached. Location Iberian Peninsula. Taxon Birds. Methods In our work, we analyse the roles played by human activities, climatic matching and spatial connectivity on the two main underlying processes shaping the spread of invasive species (i.e. colonization and extinction) using a dynamic modelling approach. We use a large data set that has recorded the occurrence of two invasive bird species-the ring-necked (Psittacula krameri) and the monk (Myiopsitta monachus) parakeets-in the Iberian Peninsula from 1991 to 2016. Results Human activities and climate matching play a role on species range dynamics. Human influence and urbanization were the most relevant factors explaining colonization. Additionally, an effect of climate matching was found. Persistence (the inverse of extinction) was mainly affected by human influence for the monk parakeet and by the extent of urban environments for the ring-necked parakeet. Main conclusions Human activities play a major role not only on colonization of new locations, but also on persistence during range expansion. Additionally, natural processes-notably climate matching-also affect new colonizations. These findings add to our understanding of the mechanisms that might allow alien species to expand their geographic range at new locations and might help to improve our capacity to assess invasion risks and impacts accurately.