Worldwide impact of alien parrots (Aves Psittaciformes) on native biodiversity and environment: a review

Abstract

More than 16% of parrot species (Aves Psittaciformes) of the world have currently established at least one breeding population outside their natural distribution ranges. Though including the most introduced bird species all over the world, their interactions with native biodiversity and environments are still poorly known. In this paper, we summarize current knowledge about impacts of introduced Psittaciformes and we identify possible gaps to be filled with future research. Breeding site requirements of alien parrots, e.g. trunk cavities, indicate potential routes of direct and indirect competition with native hole-nesting bird species. Interactions with arboreal rodents, bats and insects are poorly documented, but appear to be limited. Psittaciformes potentially affect economy and human wellness, being responsible for damage to crops and to electrical infrastructures. Association with noise pollution has also been suggested, as many alien populations breed in urban parks or close to human settlements. Psittaciformes are potential reservoirs of Chlamydophila psittaci, the etiological agent of human psittacosis, and other diseases transmittable to humans and wildlife. Less is known about impact on native flora as well as on ecosystem functions. Predictive research and information on ecosystem recovery after parrot removal are scarce too, as eradication programs are often hampered by the emotional affiliation linked to these birds.

KEY WORDS:

• alien species
• introduced parakeets
• competition
• crop damages
• diseases

ACKNOWLEDGEMENTS

We would like to thank C. Gotti and D. Giunchi, who have been of decisive help for data collection. P. Clergeau, P. Hockey, L. Ancillotto, M. Braun, P. Edelaar, A. Fellous, M. Galuppi, H. Gebhardt, L. Hart, E. Koch, M. Koopman, C. Paoletti and U. Roll provided us valuable information. We acknowledge T. Blackburn and J. Groombridge, as well as three anonymous referees, for their helpful recommendations on our draft. A very special thank you to G. Mazza and E. Tricarico for their useful suggestions. O. Melaiu (University of Pisa), F. Lessio (University of Turin), G. Zazzeri (University of Egham) and G.P. Jennings (Google Ireland) kindly revised the first version of our manuscript. The authors would like to acknowledge the support provided by European Cooperation in Science and Technology (COST) for the realization of this review. The contents of this review are the authors’ responsibility and neither COST nor any person acting on its behalf is responsible for the use which might be made of the information contained in it.