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Titre : Selección de alimento y hábitat por vicuñas silvestres de la reserva provincial Los Andes (Salta, Argentina)

Food and habitat selection in wild vicuña in Los Andes provincial reserve (Salta, Argentina)

Auteur : Mosca Torres, María Eugenia

Université de soutenance : Universidad de Buenos Aires (Instituto Argentino de Investigaciones de las Zonas Áridas (IADIZA) )

Grade : Doctor de la Universidad de Buenos Aires en el área de Ciencias Biológicas 2010

Résumé
This thesis examines food and habitat selection by vicuñas (Vicugna vicugna, Molina 1782) within the framework of the optimal foraging theory. This theory predicts that individuals will narrow their dietary range in the season of highest resource availability and expand their diet during the unfavourable season due to decline in availability of high-quality items. With regard to habitat, it predicts that animals will select those patches exhibiting greater abundance of nutritional food items. However, social structure can strongly affect this selection strategy. The goal of this thesis was to identify food and habitat selection patterns of vicuñas during seasons of maximum and minimum resource availability, and interpret such patterns within the above conceptual framework. The selection of both resources was restricted by environmental variables (season of the year and food availability), and by the pronounced social structure typical of this species. Plant availability varied between seasons and between years, which influenced selection of dietary items and, accordingly, microhabitat selection. These variations in selection were detected for both territorial and non-territorial vicuñas.

Mots clés : CAMELIDOS ; TEORIA DE FORRAJEO OPTIMO ; DIETA ; ESTRUCTURA SOCIAL ; COMPORTAMIENTO ; ZONAS ARIDAS ; CAMELIDS ; OPTIMAL FORAGING THEORY ; DIET ; SOCIAL STRUCTURE ; BEHAVIOUR ; ARID ENVIRONMENT

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