Summer diet selection of a rock specialist: the Wolffsohn´s viscacha (Lagidium wolffsohni) in protected natural area of Pinturas River, Cueva de las Manos, Patagonia, Argentina

A study of the Wolffsohn’s viscacha (Lagidium wolffsohni) in Patagonia, Argentina, reveals that this rock-specialist herbivore exhibits a highly selective summer diet, favoring grasses and specific shrubs near rocky outcrops. The research found that the viscacha's diet is narrow (Bst = 0.31 ± 0.04), with 81% composed of high-quality grasses such as Festuca pallescens, Pappostipa spp., and Poa spp., alongside the shrub Berberis heterophyla. This selective feeding behavior, similar to that of the southern vizcacha, suggests an adaptation to maximize nutrient intake while minimizing foraging effort. The study used microhistological analysis of fecal pellets from 83 groups and vegetation cover estimates on three rocky outcrops to assess diet composition and trophic specialization. These findings highlight the viscacha's reliance on specific food sources in summer, which may have implications for its conservation status, currently listed as Data Deficient by the IUCN.

Galende, G. I., & Vega, R. (2020). Summer diet selection of a rock specialist: the Wolffsohn´s viscacha (Lagidium wolffsohni) in protected natural area of Pinturas River, Cueva de las Manos, Patagonia, Argentina. Studies on Neotropical Fauna and Environment, 56(2), 135–145. https://doi.org/10.1080/01650521.2020.1763763