Diet of Huemul deer (Hippocamelus bisulcus) in Nahuel Huapi National Park, Argentina

Abstract

We determined the diet of a small population of Huemul deer (Hippocamelus bisulcus) in Nahuel Huapi National Park, Argentina, using microhistological analysis of fecal samples. The study area is of special interest for conservation because of the ingression of the introduced European red deer (Cervus elaphus). Thirty-two food items were identified as components of the diet, with Maytenus sp. and Nothofagus pumilio being the most consumed. These items also comprise a high proportion of the diet of red deer, which leads us to expect high trophic overlap wherever these two herbivores coexist, producing the displacement of the huemul to less favorable areas, and increasing its vulnerability.

Determinamos la dieta de una pequeña población del ciervo huemul (Hippocamelus bisulcus) en el Parque Nacional Nahuel Huapi, Argentina. Utilizando el análisis microhistológico de heces. El área de estudio es de especial interés para su conservación debido a la ingresión del ciervo colorado (Cervus elaphus) introducido de Europa. Se identificaron en la dieta un total de treinta y dos items alimentarios, siendo los más consumidos Maytenus sp. y Nothofagus pumilio. Estos items también comprenden una alta proporción de la dieta del ciervo colorado, lo que nos conduce a esperar una alta superposición trófica cuando estos dos herbívoros coexisten, provocando un desplazamiento del huemul hacia áreas menos favorables y aumentando su vulnerabilidad.

Keywords:

• Cervids
• Hippocamelus bisulcus
• interactions
• conservation
• endangered species
• feeding strategies
• Argentina

Acknowledgments

We thank Estela Raffaele, Susan Walker and Mónica Mermoz for useful comments on several versions of the manuscript and Claudio Chehébar, Cecilia Ezcurra and S. Walker for its translation. A. Sbriller for her advice on the microhistological analysis method. Administration of National Parks provided the permits and Universidad Nacional del Comahue support with material and necessary infrastructure.