Feeding Behavior of Herbivores in Rocky Outcrops of Northwestern Patagonia and its Importance in Conservation

GALENDE G. & RAFFAELE E.

Impacts of herbivores on vegetatio

Nova Publisher NY

Año: 2013; p. 153 - 157

Rocky outcrops in northwestern Patagonia Argentina occur in a variety of landscapes from scattered small rocky patches in the steppe to the high Andean mountains in the Nothofagus forests. These formations represent slightly disturbed habitats with a wide variety of flora and fauna, and are considered ?true refuges? of biodiversity because many of these sites have species of high conservation value. The rocky outcrops provide favorable conditions for plants and support a distinct flora with uncommon and rare species highly different from the surrounding vegetation communities. In addition, populations of rare plants and animals often exhibit patchy distribution in a natural condition. The heterogeneous structure of these environments with cracks, overhangs, and high diversity of vegetal species is accompanied by a high diversity of birds, small mammals, and reptiles. Despite the interesting characteristics of these unique ecosystems, the rocky outcrops have been little studied from the viewpoint of ecological and biological research which rarely attempts to interpret the relationships between biota and the physical characteristics of this environment. Opportunities for protecting outcrops in the steppes still exist in northwestern Patagonia. However, land protection strategies require information about the species diversity, natural disturbances, and a fundamental understanding of the ecological interactions. A central aspect in this regard is to interpret the feeding behavior and ecology of associated species in this habitat. In this chapter, we provided some recent insights of the different native fauna and plant species communities associated with the rocky outcrops, and the influences of exotic herbivores on the vegetation particularly on their interactions with a native herbivore, the mountain viscacha (Lagidium viscacia). This is a rock-specialist species that inhabits small colonies in isolated rocky outcrops, and by its feeding behavior is considered an obligatory specialist. These characteristics make it highly vulnerable to changes in food availability, for example overgrazing by alien species. Considering that herbivores may affect the structure of vegetation by changing plant composition, density and patchy distribution, then the increase of impacts on food resources and habitat quality could be threats to local wildlife. The knowledge of herbivores in this ecological context provides essential elements to develop management strategies that contribute to the conservation of these special rocky refuges with high diversity of flora and fauna.