Alien birds in Argentina: pathways, characteristics and ecological roles.
Currently, there is a consensus that biological invasions are one of the most important factors in global change due to their ability to modify structures and functions of many communities. The aim of this work was to provide an exhaustive assessment of the alien birds of Argentina, their routes of entry, impacts, and a synthesis of their attributes. We reviewed and compiled data from a variety of sources and databases on alien birds in Argentina and provide a summary for ten species that had been introduced. Introductions occurred in two peaks, one at the end of the nineteenth century and the other during the 1990s. Most of species entered through the Pampas, Espinal, Bosque and Estepas Patagónica ecoregions between 34° and 50° south. Reasons for these introductions include game birds (Silver Pheasant Lophura nycthemera, California Quail Callipepla californica), domestic consumption (Mallard Anas platyrhynchos, Graylag Goose Anser anser, Rock pigeon Columba livia), pets (European Greenfinch Chloris chloris, European Goldfinch Carduelis carduelis, European Starling Sturnus vulgaris, Crested Myna Acridotheres cristatellus, House Sparrow Passer domesticus). These species occupy ecoregions similar to those of their origins, however most have experienced an expansion in the range of ecological conditions within their new habitats. These species provide opportunity for understanding the dynamics of invasions since they provide a diversity in their ecology and environmental needs.