Threats for bird population restoration: A systematic review

Although widespread, actions aiming at the restoration of native species populations within their indigenous range still lack a clear definition of success, given the high degree of variability in species needs. In this sense, to understand and manage the mechanisms that lead to reintroduction or reinforcement failures may be a more feasible alternative to ensure conservation objectives. In this study, we aimed to systematize the main drivers that can negatively impact bird population restoration according to researchers and practitioners. Thus, a systematic review was performed in peer-reviewed journals, identifying 75 attempts, conducted from 1990 to 2016, in 30 countries involving 64 bird species and subspecies. Thirteen drivers that negatively impact reintroduction or reinforcement attempts were identified, where predation, unexpected dispersal movement and diseases were the main factors. We believe that if these drivers were prioritized during pre-release planning and post-release monitoring, restoration population programs would be more successful.