Diet of Guanaco and Red Deer in Neuquen Province, Argentina

Abstract

Spring and summer diets of guanaco (Lama guanicoe) and red deer (Cervus elaphus) in northern Patagonia were determined by the microhistological analysis of their droppings. Forbs were the main components of the guanaco diet both in spring and summer. Spring diet of deer was comprised mainly of grasses, whereas the summer was comprised equally of trees, shrubs, forbs and grasses. These results indicate differential use of the area by both species. The 2 main wild ungulate species coexisting with domestic sheep in a large section of the southern Andean foothills are guanaco (Lama guanicoe) and red deer (Cervus elaphus). This area, called precordillera, forms an ecotone between moist nothofagus forest to the west and arid steppe vegetation to the east (Anchorena 1978). Sheep were first brought to the area toward the end of last century. Overgrazing by the sheep has been blamed for habitat deterioration. Guanaco is a species native to the area and widely distributed throughout all Patagonia. Its number have decreased considerably as a result of deterioriating habitat and excessive hunting (Raedeke 1980). Red deer were introduced in the area at the beginning of the century and have since increased considerably in number and area of distribution (Staudt 1978). Guanaco, deer, and sheep diets have been determined separately in a variety of different habitats (Crocker 1959, Wardle et al. 1970, Mitchell et al. 1977, Bonvissuto and Moricz 1981, Ramirez et al. 1981, Tilton and Willard 1981, Clutton-Brock et al. 1982, Bonvissuto et al. 1983). The purpose of this study was to expand the knowledge base by determining the spring and summer diet of guanaco and deer feeding on the same precordillera area.