Densidad y selección de hábitat de guanaco en el sitio Patrimonio de la Humanidad Ischigualasto-Talampaya

PABLO ACEBES; JUAN TRABA; JUAN E. MALO; RAMIRO OVEJERO; C. E. BORGHI

Catamarca

Congreso; IV Congreso Mundial de Camélidos; 2006

First estimations on guanaco population and habitat selection are presented for an area of Montedesert. In the wet and dry seasos 2005 transects were carried out throughout the Ischigualasto Provincial Park (San Juan Argentina). In parallel during systematic survey through the area all guanaco obse rvations were GPS located and the habitat occupied by individuals/groups identified. Population densities were estimated with DISTANCE software, showing differences between the wet (0.597 ind/km2) and dry seasons (0.115 ind/km2). Such densities are only slightly lower than those found for Tierra de Fuego or Península Valdés. Thus, the population estimate for the Park would range between 75 and 388 individuals (in dry and wet seasons  respectively). Guanacos showed a differential habitat selection between seasons, (chi-cuadrado = 23.85; gl = 9; p < 0.01), preferentially selecting the mixed creosote bushland and Atriplex-dominated barelands during the wet season, and open shrublands and cacti -dominated slopes in the dry season. Our results point to strong seaso nal oscillations in guanaco populations and to an intense use of the most productive patches.