Guanaco´s diet and forage preferences in Nothofagus forest environments of Tierra del Fuego, Argentina.

QUINTEROS, C. P.; BAVA, J. O.; GOBBI, M. E.; DEFOSSÉ, G.E

Forest Systems

INIA

Lugar: Madrid; Año: 2017

Guanaco (Lama guanicoe Müller), is a South American native ungulate widely distributed in Patagonia, which in the island of Tierra del Fuego (TF), extends its habitat into Nothofagus spp. forests. Within these forests, guanacos consume lenga (Nothofagus pumilio) leaves and twigs, and other understory species. The aim of this work was to determine: 1) the spring and summer diet of free ranging guanacos, and 2) which plants, grown in the forest understory, guanacos do prefer, or avoid, in these seasons of great forage abundance. On three representative areas of TF which combined Nothofagus forests and adjacent meadows (vegas), guanacos diet was determined by comparing epidermal and non-epidermal plant fragments with micro-histological analyses of feces. During spring, 48% of guanacos diet was composed of lenga leaves, 30% of grass-like species, 15% of grasses, and less than 7% of herbs, shrubs, and lichens. In summer, 40% of the diet was composed of grasses, 30% oflenga leaves, 25% of grass-like species and the rest corresponded to herbs,shrubs, and lichens. Within the forest understory, guanaco selected lenga leaves and twigs, grass species were consumed according to their availability(or sometimes rejected), while other herbs were not consumed at all. Guanacosconsumption preference for lenga, even considering the high availability of other forages, could adversely affect forest regeneration.