Dry Season Forage Selection by Alpaca (Lama pacos) in Southern Peru

Abstract

Two hundred eighty adult female alpacas (Lama pacos) and 200 tui alpacas (young alpacas 3-7 months of age) were grazed on a Festuca-Calamagrostis association at the South American Camelids Research Station, La Raya, Peru, during the dry season and early wet season of 1981 (June-December). Vegetation was sampled monthly during this period for herbage yield by species. Fecal material from both adult female alpaca and tui alpaca was collected monthly for microhistological analyses of food habits. Alpacas were primarily grazers rather than forb eaters during the dry season and early wet period of 1981. Forage classes consumed were different for adult and tui alpaca. Tui alpaca consumed more grass-like plants and forbs than adults during the driest months. Diet indices revealed the following as highly selected, common forage species: Eleocharis albibracteata, Poa. sp., Calamagrostis heterophylla, C. vicunarum, Alchemilla pinnata, Muhlenbergia fastigiata, and Carex spp. Highly selected, trace species were P. gymnantha, M. peruviana, Stipa brachiphylla, Ranunculus limoselloides, and Trifolium amabile. Festuca dolichophylla had been considered by range managers as highly preferred species overall. However, because it was the most abundant species (73% of the total forage yield), F. dolichophylla had a low selection index during the dry season. Alpacas consumed remarkable quantities of grass seeds (up to 20% of the diet) during the driest months of the year, apparently compensating for low quality forage.