Feeding habits of guanacosLama guanicoe in the high Andes of north-central Chile

Abstract

2003. Feeding habits of guanacos Lama guanicoe in the high Andes of north-central Chile. Acta Theriologica 48: 229-237.The guanaco Lama guanicoe Muller, 1776 has a wide distribution along the Andes and Patagonia. We studied the feeding behaviour of a guanaco population that lives over 4100 m altitude in the Andes of north-central Chile. By contrasting the diet of guanacos during a dry year with that of a wet year and comparing it with the plant availabilities in the field, we tested the hypothesis that the guanaco is a generalist herbivore. We predicted that under such extreme habitat conditions guanacos should consume whatever plant species are available in the environment, especially in a dry year, when vegetation is scarcer. In addition, we compared its diet at three different age classes. We estimated the diet through the microhistological analysis of plant remains found in guanaco pellets collected during January of 1997 (ie after a dry year) and 1998 (ie after a wet year; 41 vs 495 mm, respectively). Then, we computed dietary preferences, food niche-breadth, and food-niche overlap between years and among age classes. Vegetation cover and plant species richness were higher during the wet than during the dry year. The most common plants in the environment were perennial graminoids and legumes. Contrary to our prediction, the guanaco preferred a few plant species, showing a relatively narrow diet breadth that changed little between years differing in plant abundances. The diet proportions differed among the three age classes, however. Our data indicate that at least in this high-elevation population, guanacos are selective and non-opportunistic herbivores. This specialized feeding behaviour is puzzling given the energetic demands of living in a harsh environment with low availabilities of resources. The hypothesis that this is due to the lower palatability of the plants not eaten, remains to be tested.

Trophic preferences in an assemblage of mammal herbivores from Andean Puna (Northern Chile)

“…Regarding the herbaceous plants, the Poaceae S. chrysophylla, highly consumed by the short-tailed chinchilla and the vicuña, has already been reported for the diet of other camelids and chinchillids (Benítez et al, 2006;Cajal, 1989;Cortés et al, 2002bCortés et al, , 2003a. Genus Stipa includes some species important as food source for herbivorous vertebrates (e.g., camelids, cattle, rodents) in the areas where they are dominant (Benítez et al, 2006;Cortés et al, 2002b).…”

Does the presence of livestock alter the trophic behaviour of sympatric populations of wild camelids Vicugna vicugna Molina 1782 and Lama guanicoe Müller 1976 (Artiodactyla: Camelidae)?: Evidence from Central Andes

“…In the North of Chile, L. guanicoe is considered locally as Endangered Species (SAG 2012). As for this species diet, in high Andean areas with wetlands L. guanicoe has been reported to eat mainly grasses and pseudograsses, whereas in wetlands absence its diet consists mainly on grasses, and secondarily shrubs (Cortés et al 2003, Puig et al 2011.…”

“…From a feces pool made from each sample, a microhistological preparation was composed through Williams's technique (Williams 1962, Dizeo de Strittmatter 1984. This method was repeated for each of the samples collected, obtaining a total of 10 preparations per species (Cortés et al 2003, Cortés et al 2006, Tirado et al 2012.…”

“…Observations were carried out with a Nikon® (Eclipse E-200) with a reticulate lens of 20 x 20 quadrants with a magnifi cation of 40X. Fields with less than 50% of the area used were excluded (Cortés et al 2003, Cortés et al 2006. Epidermic material was identifi ed at species level using the reference collection.…”

Análisis De Isótopos Estables en Colágeno De Huesos De Camélidos De Quebrada Tulán, Puna De Atacama, Periodo Formativo Temprano: Ca. 3.100-2.400 A.P

“…Si se consideran los datos relacionados a las preferencias alimentarias de los camélidos domésticos y silvestres para zonas desérticas y semidesérticas de altura se observa una clara preferencia en el consumo de gramíneas tanto en sectores de pajonales como de bofedales. los estudios realizados por Cortés et al (2003) en los sectores cordilleranos de Chile norte-centro sobre la dieta del guanaco muestran una alta inclusión de Stipa chrysophylla (Poaceae) tanto en los periodos secos como húmedos. En el caso de los hábitos alimentarios del guanaco en la costa del Desierto de Atacama, Raedeke y Simonetti (1988) identificaron una mayor concentración de líquenes como base de la dieta durante todas las estaciones, seguido por Euphorbia lactiflua (Euphorbiaceae) y Solana sp.…”