Invasive birds in a novel landscape: habitat associations and effects on established species

Studying the relationships among introduced species, their preferred habitats, and native species can be important for predicting the effects of invasions on native populations. Examining the colonization of North America by the Eurasian collared-dove Streptopelia decaocto, we quantified the habitat characteristics of sites most likely to be occupied by this invasive bird species in the early stages of the invasion. Further, we studied the relationship between collared-dove abundance and the abundance of other dove species in the study area, anticipating a negative effect on established species following the introduction of a potential competitor. Linking satellite-derived landcover data with winter bird community data gathered from 444 study sites in Florida, USA from 1999 to 2008, we found that collared-doves were more likely to occur in landscapes that had been highly-modified by human activity than in forested landscapes. Collared-dove abundance increased as the proportion of the landscape characterized as low-intensity development and medium/high-intensity development increased. The probability of collared-doves occurring at a site was also related to the spatial proximity of other sites reporting doves (positive spatial autocorrelation). Contrary to our expectations, the site-level abundance of four other dove species all increased with collared-dove abundance throughout the sampling period. Interactions between collared-doves and native species should be further studied in different environments as this invasive bird rapidly colonizes North America.