SHORT COMMUNICATION

Abstract We studied abundance, habitat use and social structureofan isolatedpopulationof guanacos in theLihue Calel National Park in central Argentina, based on data from foot surveys during 1998–2000. Based on topography and vegetation characteristics we distinguished three types of habitat: hills, valleys and piedmonts, and lowlands. Three types of social groups were observed: solitary males, family groups and male groups. The guanacos used hills preferentially, followed by valley and piedmont. The guanacos avoided the lowlands where the vegetation is dense. Habitat selection, both on a coarse and a fine scale, could be explained by habitat quality and possibly also predator avoidance behaviour. Abundance of guanacos increased by 21 % over the 3-year-study period. However, the specificity of habitat requirements of guanacos and the susceptibility of the study area to wildfires could cause guanacos to move into sub-optimal areas were they are more vulnerable to predation and human persecution