Fact Sheet on Guanaco Migration

The guanaco is the most widespread herbivore in South America, and the continent’s only ungulate with documented migratory behavior. Guanacos in Argentina’s Monte León National Park and surrounding lands – predominantly coastal shrublands and grasslands – typically perform elevational migrations. They generally spend winters in the northern extent of their migratory range, near where the Santa Cruz River carves a broad, low-elevation valley that may provide shelter from snow and harsh winter conditions. As the austral spring approaches in September and October, guanacos migrate south to areas ~200m higher in elevation than their winter range, where they give birth and forage on vegetation in optimal nutritional stages. November is the start of the mating season, where males establish breeding territories that they defend through the summer. The timing of guanaco movements is flexible, and influenced by year-to-year weather variability. During the winter months, some guanacos also make escape movements east towards the coast when severe environmental conditions likely drive them away from their usual ranges.