The ecology of bird introductions

A growing number of species have been transported and introduced by humans to new locations and have established self-sustaining wild populations beyond their natural range limits. Many of these species go on to have significant environmental or economic impacts. However, not all species transported and introduced to new locations succeed in establishing wild populations, and of the established species only some become widespread and abundant. What factors underlie this variation in invasion success? Here, we review progress that has been made in identifying factors underpinning invasion success from studies of bird introductions. We review what is known about the introduction, establishment, and spread of introduced bird species, focusing on comparative studies that use historical records to test hypotheses about what factors determine success at different stages in the invasion process. We close with suggestions for future research.