Galemys 21 (nº especial): 121-132, 2009 ISSN: 1137-8700 121 EXPANSION OF THE INTRODUCED WILD BOAR (Sus scrofa) IN THE ANDEAN REGION, ARGENTINEAN PATAGONIA MOISÉS PESCADOR 1• , JAVIER SANGUINETTI 2 , HERNÁN PASTORE 3 AND SALVADOR PERIS 1* 1. Departamento de Zoología, Facultad de Biología, Universidad de Salamanca 37071 Salamanca. (moises@usal.es)• (peris@usal.es)* 2. Sección Técnica, Parque Nacional Lanín, San Martín de los Andes, Argentina. (sanguinetti@fronteradigital.net.ar) 3. Departamento de Ecología, Centro Regional Universidad de Bariloche, Universidad Nacional del Comahué, Bariloche, Quintral 1250, R8400 FRF Bariloche, Río Negro, Argentina. (hpastore@crub.uncoma.edu.ar) ABSTRACT Wild boar (Sus scrofa) from Siberia were introduced into Patagonia (Argentina) between 1904 and the 1920s. Wild boar were first observed in the Lanín National Park in the 1980s. Their invasion pattern follows rivers and lakes, moving vertically from the original release site in the eastern steppes to the western hillsides. During the last 20 years, the area occupied by wild boar has increased throughout the park from 10% in 1985 to nearly 30% two decades later, mainly in Araucaria-Nothofagus forests and scrubland. These landscapes hold 83% of the current wild boar distribution, with a statistically significant three-fold increase (Sr = 0.891, p<0.01). Pine plantations, grassland–steppe and bare ground are less favoured by the species, with only a two-fold increase or less during the last two decades. Its distribution range has increased to over 70000 ha during the last 20 years, with an average increase of about 3500 ha/y. At this rate, the species would need 50-60 years to cover the entire Lanín National Park, but cold winters, years with poor Araucaria-Nothofagus seed production, increasing predation by puma (Puma concolor), and the possible appearance of new parasites and diseases as the population increases could limit wild boar dispersal to a lower rate. Key words: Exotic species, expansion, wild boar, Patagonia. RESUMEN Expansión del jabalí (Sus scrofa) en la región andina de la Patagonia argentina El jabalí (Sus scrofa) fue introducido en Patagonia (Argentina) desde 1904 hasta la década de 1920, principalmente con animales importados de Siberia. Las primeras observaciones de jabalí en el Parque Nacional Lanín fueron realizadas en los años 80 del pasado siglo. La pauta de la invasión de la especie se desarrolla por ríos y lagos, moviéndose hacia arriba en altitud, desde los