CONICET | Buscador de Institutos y Recursos Humanos

A large number of protected areas have been impacted by biological invasions, threatening their biodiversity. Understanding habitat requirements of invasive species can be crucial for management and conservation decisions. Wild boar is one of the largest invasive species in Argentina, which occupies many ecoregions. The quality of its habitat is determined by the availability of free water and food; and by vegetation cover. The aim of our study was to assess the habitat use patterns of wild boar in the MaB Reserve of Ñacuñán, Argentina, at two scales (broad and small scale). Eighty transects of 1 km were set up, covering the study area. Transect surveys were conducted two times in the year 2008 (wet and dry season). Wild boar signs (tracks and rooting) were recorded within 3 m of either side of each transect. At each sign we established a plot (50 m2) where we recorded information on habitat and anthropogenic variables. We measured the same variables in plots were the wild boar was absent. To detect patterns of habitat use at broad scale we used Chi-squared contingency test. To analyze patterns of habitat use at a small scale we used multiple logistic regression analysis. During both seasons the wild boar showed preferences for a particular habitat (creosotebush shrubland) for feeding, avoiding mesquite forest and sand dunes (X2= 16.83, df = 2, p= 0.0002 wet season; X2= 6.51, df=2, p= 0.038 dry season). There were not significant differences with respects to tracks. At small scale, we found that the presence of wild boar during the wet season was mainly associated to herbaceous cover and distance to nearest water source. Instead, during the dry season we found a positive association of wild boar with shrub < 1 m and with litter cover, and a negative association with herbaceous cover.